international sugar - inicio · international sugar journal 2013, vol. 115, no. 1372 229 for the...

April 2013

Volume CXV: Issue No. 1372

focus: CANe trANsport, juICe ClArIfICAtIoN ANd bAgAsse depIthINg

sugar processing and refining > power and cogeneration > biorenewables > agricultural production

sugarJOURNALwww.internationalsugarjournal.com

INTERNATIONAL

Join ISJ in our Global Sugar Network

For more information turn to pages 284-285

In need of reliable system solutions that allow you to focus on your core business? Rexroth – your one stop shop for excellent drive and control solutions that maximize performance and help optimize productivity. Regardless of technology or location our global organization can provide you with the right solution to meet the challenging everyday demands of the sugar industry. You can focus on your core business, relying on our high quality solutions and global network to provide complete peace of mind.

Bosch Rexroth AG www.boschrexroth.com/sugar

Photo by courtesy of Hägglunds.

BR_ISJ_Outlook_2013.indd 1 2012-11-13 10:06

Not currently an ISJ subscriber?

The complete value chain from sugarcane and beet production right through to sugar processing and sugar refining PLUS the latest developments in the biofuelsand biobased sectors

How you will benefi t from an ISJ subscription:• The latest in-depth news, analysis and intelligence from your

industry in one place • Reliable information that could improve your efficiency and save

your company money • React quickest with the latest issue available online at

www.internationalsugarjournal.com

The World’s Leading Sugar Industry Magazine• Cane sugar manufacturing • Beet sugar manufacturing • Sugar refining • Equipment and machinery • Alternative sweeteners • Biofuels • Cogeneration

• Nutrition and health

• Environmental issues

• Food and non-food uses of sugar

• By-products - molasses, alcohol and vinasse

• Economics, trade and legislation

From time to time we may wish to send you information and offers about Informa plc products and services. If you do not wish to receive this information, please tick the following box. In some circumstances we may wish to pass on your details to carefully selected 3rd parties, in order for them to send you relevant information and offers. If you would like us to pass on your details in this way, please tick the following box. Data Protection: Personal Data supplied is subject to the Data Protection Act 1998. The personal information shown on this form, and/or provided by you, will be held on a database and may be shared with companies in the Informa Group in the UK and internationally. It may be used to keep you, or any additional names provided by you, up to date with developments in your industry. If you have any questions about Informa’s use of your data please write to the Database Manager, PO Box 461, West Byfl eet, KT14 9BN. Tel: +44 (0)20 7017 5239 Fax: +44 (0) 20 7017 6241 or email [email protected]

International Sugar Journal one year sub:UK £600 Europe €750 Rest of World US$955

To enquire about advertising in ISJ, please contact [email protected]

or call +44 (20) 701 77559

3 easy ways to subscribe...1. To order online, please visit

https://store.agra-net.com/isj.html2. Call Alex Cast on +44 (20) 7017 750673. Or email [email protected]

for a FREE sample copy


1010_TW_ISJ Subs ad update.indd 1 21/03/2013 07:52

229www.internationalsugarjournal.comINTERNATIONAL SUGAR JOURNAL 2013, VOL. 115, NO. 1372

For the latest sugar industry news go to: www.internationalsugarjournal.comsugar

JOURNALwww.internationalsugarjournal.com

INTERNATIONAL

Editorial Comment

In late October last year, Dow Jones Newswires reported that Petrobras, Brazil’s state-controlled oil producer, was backing out of a multi-billion-dollar (U$ 3.45 billion) project to build a 1,300-kilometer ethanol pipeline it is jointly responsible for. This was confirmed by one of the project partners, Cosan; the leading sugar producer in Brazil. The project commenced in 2010 and was scheduled to be completed in 2016. The plan is to connect sugarcane growing regions to storage and distribution centers in southeastern São Paulo and Rio de Janeiro states. This decision, to date, has not rung alarm bells in the sugar industry.

Arnaldo Correa, director of sugar and ethanol consultancy Archer Consulting, responding to the news at the time said that Petrobras is probably reinforcing the perception held by many in the sugarcane industry that the Brazilian government sees ethanol as less of a priority than it once did.

But this seems to be a rather facile observation.

Probably the main reason for Petrobras pulling out of the project is to do with the fact that it sees any further investment as wasteful; the pipeline may become a white elephant in due course. This is mainly because there is considerable reserve of off-shore oil for Brazil to tap into. When the first major field was tapped, the then President Luiz Inácio Lula da Silva was reported as saying that “God is Brazilian”.

Petrobras estimates there are over 15 billion barrels of oil just in the fields discovered so far. Three times this much is estimated to lie under the massive “presalt” reservoirs offshore. This rivals Libya’s reserve.

In the recently published report 1 from the Harvard Kennedy School, the lead author, Leonardo Maugeri, states that “Contrary to what most people believe, oil supply capacity is growing worldwide at such an unprecedented level that it might outpace consumption.” Brazil is identified in the report as one of the four countries with “highest potential in terms of effective production capacity growth” for oil production.

In response to rocketing oil prices in the ‘70s, the Brazilian government initiated the National Alcohol Programme ‘ProAlcool’ in 1975. The intention was to substitute gasoline with cane based ethanol in automobiles. Since then, the cane ethanol sector has ballooned: cane production increased from 50 million tonnes in 1970 to over 600 million tonnes today. Over 50% of cane is diverted to ethanol production (Figure 2). Of the 440 plants in 2012, 267 produced both sugar and ethanol, 153 exclusively produced ethanol and the remaining 20 produced exclusively sugar.

The ProAlcool Programme was effectively a knee-jerk reaction by policy makers in response to the oil crisis. The decision by Petrobras to back off from the pipeline project does suggest that soon as the oil production commences in full gear, it is likely to jettison the programme.

This may send the sugar industry in tail spin with the collapse in prices from oversupply, unless policy makers observe a sensible transition period for diversion of cane into production of biochemical or biobased products. Only time will tell. •

Arvind Chudasama

Reference1 Maugeri, L. (2012) “Oil: The Next Revolution” The unprecedented upsurge of oil production capacity and what it means for the world. http://belfercenter.ksg.harvard.edu/publication/22144/oil.html

Chronicle of a death foretold - Brazilian biofuels industry

Figure 1. Worldwide potential addition crude oil and natural gas liquids output to 2020

Figure 2. Centre South Brazilian mills sugar/ethanol split

Source: Harvard Kennedy School Source: Unica, Macquarie

Panel of RefereesL. Jean Claude Autrey PhD, DSc, CBiol, FIBiol, Former Director, Mauritius Sugar Industry Research Institute, Mauritius.

M. Asadi PhD, Former Director of Research at Monitor (now Michigan) Sugar Company, USA.

L.S.M. Bento BSc, PhD, Formerly Audubon Sugar Institute, USA.

J.J. Bhagat Mission Director, Sugar Technology Mission, India.

L. Bichara Rocha PhD, Senior Economist, International Sugar Organisation, UK.

S.J. Clarke PhD, Director of Industrial Research and Development, Florida Crystals, USA.

J.C. Comstock PhD, Research Leader, USDA-ARS-SAA, Canal Point, Florida, USA.

L. Corcodel PhD, Head of Sugar Processing and Industrials Innovations, eRcane, Reunion, France.

S. Davis MSc, Head: Processing Division, Sugar Milling Research Institute, South Africa.

D. Day PhD, Audubon Sugar Institute, USA.

S.J. Edmé PhD, Research Geneticist, USDA-ARS Sugarcane Field Station, Florida, USA.

G. Eggleston PhD, Lead Scientist, SRRC-ARS-USDA, USA.

C. Garson MEngSc, BE (Mech), Bundaberg Walkers Engineering Ltd, Australia.

B. Glaz MSc, Research Agronomist, USDA-ARS-SAA, Canal Point, Florida, USA.

M.A. Godshall BSc, MSc, Formerly Managing Director, SPRI, USA.

D.K. Goel BEng (Mech), Executive Vice President, ISGEC John Thompson, India.

M. Inkson CEng, PhD, MIChemE, FEI Director, Sugar Knowledge International, UK.

P. Jackson PhD, CSIRO Plant Industry, Australia.

G.L. James PhD, DIC, CBiol, FIBiol, Retired Technical Adviser - Agronomy.

T. Johnson BS, MS, Chief Chemist and Manager of Quality Control, Sugarcane Growers Cooperative of Florida, USA.

L. Jolly BAgricEcon(Hons), Senior Economist, International Sugar Organisation, UK.

J. Joyce BEChem, MBA, Sugar Process Consultant, James Joyce & Associates, Australia.

C.A. Kimbeng PhD, Asst Prof, Dept of Agronomy and Environmental Management, Louisiana State University, USA.

M. Krishnamurthi PhD, Chief Executive, Sadhana Agritech Services and Consultancies Private Ltd, Bangalore, India.

V. Kochergin PhD, PE Audubon Sugar Institute, USA.

G.W. Leslie MSc, Entomologist, SASRI, South Africa.

S.E. Lingle PhD, Research Plant Physiologist, USDA-ARS-SRRC, New Orleans, USA.

P. Malein BA, MA, Head of Agriculture, Booker Tate Ltd, UK.

J.A. Mariotti PhD, Director, Tucumán Experiment Station, Argentina.

B. Muir PhD, British Sugar, UK.

H.A. Naqvi MSc, Technical Consultant, Sanghar Sugar Mills Ltd, Sanghar, Pakistan.

D. Nixon PhD, Agriculturist, Booker Tate Ltd, UK.

Y-B. Pan PhD, Research Plant Molecular Geneticist, Houma, Louisiana, USA.

L. Panella PhD, Research Leader & Research Geneticist USDA-ARS, NPA, USA.

C. Rhoten BSc, Manager of Process Technology, The Almagamated Sugar Company, USA.

M. Saska PhD, Audubon Sugar Institute, USA.

F.W. Schenck BSc, PE Consultant, Starch Hydrolysis Products, USA.

G. Shannon BAppSc, Extension Leader - North BSES Limited, Qld, Australia.

F.M. Steele PhD, Assistant Professor of Food Microbiology, Brigham Young University, USA.

P. Stevanato PhD, University of Padova, Italy.

M. Suhr CEng, BS President, MS Processes Intl, LLC, USA.

J. Torres PhD, Director Agronomy Program, CENICA-A, Colombia.

R.P. Viator PhD, Research Plant Physiologist, Houma, Louisiana, USA.

D. Weekes BSc, CEng, MlAgrE, Senior Agricultural Engineer, Booker Tate Ltd, UK.

W. Weiss Manager, Sugars International, USA.

A. Wienese MScEng(Mech), Consultant, ‘Sugarwise’.

M.S. Wright PhD Research Microbiologist, USDA-ARS-SRRC, USA.

S. Zhang PhD, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences (CATAS), China.

sugarJOURNALwww.internationalsugarjournal.com

INTERNATIONAL

INTERNATIONAL SUGAR JOURNAL 2013, VOL. 115, NO. 1372230

International Sugar JournalIBI, Guardian House, 119 Farringdon Road London EC1R 3DA, UK.

Editorial:Editor: Arvind Chudasama MSc., MAgSt. (Qld), MCLIP Email: [email protected]

Design and Production: Jane CrispinPhone: +44 (0)20 7017 7500Fax: +44 (0)20 7017 7599

Advertising:Business Development Manager: Stuart VeldenDirect: +44 (0)20 7017 7559Fax: +44 (0)20 7017 7593Email: [email protected]

Marketing and circulation:Marketing Manager: Toby WebbPhone: +44 (0)20 7017 7534

Subscriptions:Phone: +44 (0)20 7017 5540Email: [email protected]


All technical articles have been approved by our panel of distinguished referees. Other editorial material, including abstracts, appear at the discretion of the Editor.

ISSN 0020-8841

International Sugar Journal is published monthly by Informa UK Ltd.

© 2013 Informa UK Ltd. Conditions of sale: 1. All rights reserved, no part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise without prior written permission of the Publisher. Photocopying Licence: Informa UK Ltd. does not participate in a copying agreement with any Copyright Licensing Agency. Photocopying without permission is illegal. Contact the Marketing Department to obtain a photocopying license. 2. All abstracting of the content for republication and sale must have prior permission from the Publisher. 3. The publication must not be circulated outside the staff who work at the address to which it is sent, without prior agreement with the Publisher.


Product Feature

284 FPE Global wins fire damaged sugar system replacement contract

286 New products focus

Contents

April 2013

Volume CXV: Issue No. 1372sugarJOURNALwww.internationalsugarjournal.com

INTERNATIONAL

International Sugar Journal

250 Improving the harvesting and transport of whole crop harvested sugar cane

M. Inderbitzin and R. Beattie

257 Direct clear juice: A feasibility study and piloting investigation into the production of clear juice in a sugarcane diffuser

P.S. Jensen

272 A preliminary study into the environmental and economic consequences of a sugar factory depithing operation

T.J. Rainey, A.P. Mann, C.H. Bakir and I.M. O’Hara

279 Diagnosis of Sugarcane streak mosaic virus using recombinant coat protein antiserum in sugarcane

R. Viswanathan, V. Ganesh Kumar, R. Karuppaiah, M. Scindiya and C. Chinnaraja

229 Editorial comment: Chronicle of a death foretold - Brazilian biofuels industry

232 Market overview

234 Sugar industry news

240 The blackboard: Recovery and cane payment

242 Biofuels news

245 Biobased products news

247 Trends in science and technology

288 Meetings calendar

288 Advertisers’ index

Regular Items

focus: CANE TRANSPORT, JUICE CLARIFICATION AND BAGASSE DEPITHING

Compactor machine working on WC product in multi-lift road bin - see page 254

INTERNATIONAL SUGAR JOURNAL 2013, VOL. 115, NO. 1372232 www.internationalsugarjournal.com

MARKET OVERVIEW



INTERNATIONAL

General consensus amongst analysts is that there will be a significant global surplus in 2012/13. This is clearly having a bearish pressure on global price. In their latest review, Czarnikow puts the surplus at 9.1m mtrv (million metric tonnes raw value). Stock levels are rising amidst falling sugar prices as affordability drive price sensitive customers into buying.

Supply

• Globally,outputisstagnating,withproduction growing at around 2.9% compared with 6.4% and 7.8% in the previous two seasons.

• WiththeC/SBraziliancrushlastinglonger than first expected and production exceeding 34 million tonnes, the likelihood of 1Q13 production surplus continue to pressure prices.

• Czarnikowestimatesbeetsugarproduction in the EU to be 17.3m mtrv, while output from Russia and Ukraine is likely to be 5.2 and 2.4m mtrv. The US beet sugar production is expected to be 4.7m mtrv while output in Asia, covering both Japan and China, will probably be just short of expectations.

• Indianproductionisimprovingwithbetter than expected yields reported for both new plantings and ratoons (27.5m mtrv).

Demand

• Withrecordimportsofsugarduringthe second half of 2012 and then continuing into early 2013, traded volumes in the physical market appear inconsistent with a slow consumption growth environment, notes Czarnikow.

• Highstocksandabumperdomesticcrop should pressure Chinese import demand in 1H13.

• Possiblehighergasolinepricesin1Q13 as well as higher ethanol blend rates by June 2013, should increase Brazil’s demand for ethanol in the coming season resulting in more cane diverted away from sugar production.

Monthly snapshot

Year-on-year production growth has slowed significantly this year

Source: Czarnikow


Industry NEWS



INTERNATIONAL

The European Parliament voted to extend the sugar production quotas until the 2019/2020 marketing year on 13 March.

The move was carried in the parliament by a margin of 434 to 231, with eight MEPs (Members of European Parliament) abstaining. This reverses the previous commitment by the EU’s 27 member states to end the sugar quotas by 2015.

The extension of quotas is sugar beet producers, beet sugar processors and sugar traders but not some governments who were

opposed to it, along with cane sugar refiners and, food and drink companies.

Meurig Raymond, deputy president of the UK’s National Farmers’ Union, said “MEPs have listened to many of our concerns and have made meaningful changes that, if approved in the final deal, will strip out some of the unnecessary bureaucracy from the future CAP.”

Muriel Korter, the Secretary General of the European Sugar Users Association said that “Maintaining the disruptive sugar quotas until 2020 sends the wrong signal. Indeed the vote brings the EU back to outdated,

protectionist policies of the past, which distort the market and jeopardize security of supply for the entire food chain”.

The wholesale price of sugar in the EU is significantly higher than that on the international markets.

Rationale for the majority of MEPs persisting with extending the production quotas was to safeguard farmers against volatile prices, maintain continued investment in the industry, particularly in the midst of a recession. They were mindful of the previous reform in 2006 which led to the loss of 20,000 jobs. •

EU sugar quotas likely to be extended to 2020

Fiji risks losing prefer-ential access to the EU sugar market if it does not ratify the interim Economic Partnership Agreement (iEPA). Fiji rakes in around U$100 million annually from the existing deal.

Last September, Fiji was placed in a list of 18 countries from the African Caribbean and Pacific trade bloc (ACP) likely to lose preferential market access for their sugar (under the current sugar protocol) if they did not ratify the iEPA by 1st January 2014.

Denial of preferential access would mean Fiji’s sugar attracting an import duty of up to €339 from the current zero duty per tonne of raw cane sugar it exports to the EU. Under this circumstances, Fiji’s sugar industry will collapse as getting its sugar to new markets at the prevailing world price against the cost of production locally is simply not competitive.

Indications from Officials of the Fijian Government are that despite the long process of the Economic Partnership Agreements negotiations, there is likely to a resolution before the deadline. •

Fiji - Preferential access to the EU market at risk

The fall in sugar prices in US is likely to spur the Department of Agriculture into purchasing 400,000 tons of sugar in the local market to prop up prices in order to pre-empt defaults by sugar processors who borrowed $862 million under the government’s non-recourse loans or price support programme, the Wall Street Journal reported.

Names nor number of companies who received loans have not been revealed.

Sugar prices in the US have been trading at about 20 cents a pound, which are lowest in nearly four years, putting sugar processors at risk of defaulting on loans they received from the

USDA when prices were higher.According to the USDA

economist Barbara Fecso, the programme is likely to face a loss of $80 million.

The non-recourse loans programme supports the sugar industry by providing a price safety net to producers, should the domestic sugar price fall below an administered loan rate. The US Farm Bill authorises the Commodity Credit Corporation (CCC) to make loans available to domestic cane sugar and beet processors at the prevailing loan rate. Raw cane sugar and refined beet sugar is used as collateral for the loans. When the sugar is sold, the loan is repaid to the CCC. Alternatively,

the processor may forfeit stocks to the CCC as full repayment of the loan. As a result, the loan rates effectively create a floor price for sugar.

Ms Fecso suggested that should the price bounce bank by end of the month, than USDA would refrain from making the purchase.

The last time the government intervened under similar circumstances was 13 years ago. Then the loan programme incurred a loss of some $295 million, when the purchase of 132,000 tons sugar by USDA had little impact as borrowers ended up handing over to the agency 1 million tons of sugar instead of repaying their loans. •

US likely to purchase sugar in the domestic market to prevent default by processors


While there is a general consensus among the industry analysts that the outlook for sugar prices is bearish, analysts at Macquarie Commodities Research point out that there several mitigating factors that may signal a rise in prices post second quarter in 2013 after falling to 17.5 c/lb.

Macquarie analysts highlight six possible scenarios that are likely to dent the continued bearish outlook. While the output of cane will continue to increase, diversion to ethanol production is likely to increase to as much as 54% in 2013/14 compared with 50% in 2012/13. This is to address higher demand arising from “1) the government’s 5% move higher in the anhydrous/gasoline blend rate to 25%, 2) possible abolishment of the pis coffin tax rate on hydrous producers, 3) exports to meet the US’s advance biofuels mandates and 4) higher demand following the 6% rise in gasoline prices (which translates to a 4% rise in the pump price).”

With “expected tightness in corn-based ethanol production in the Jun-Aug period”, US may need to import some 3 billion litres from Brazil. Further, with transportation costs rising and the possibility of the Brazilian Real (BRL) appreciating, ethanol will become more attractive to millers than sugar.

Secondly there has been significant activity in short positions in NY’s raw sugar

futures and options market which is unlikely to continue to be rewarding, as “producers around the world” will be deterred “from investing in further expansion as profit margins start to get eroded. Thus, at these prices, risks are more likely to be on the upside, rather than downside - and funds may want to start covering their shorts. As the short position begins to contract, prices in latter 2013 could start getting a lift”.

Thirdly, while the output in some Indian states

has increased, the overall production is expected to be around 24 million tonnes. Due to low cane availability in 2012/13, some 14 mills were closed. Prospect for next year does not look as farmers in “Maharashtra, Karnataka and Tamil Nadu” may switch to other crops.

Fourthly the rise in the value of BRL, spurred on by global and domestic factors, will increase sugar production costs on the one hand, and decrease the value of exports on the other.

Fifthly, there is the usual suspect - vagaries of the weather. The extent of damage to the cane crops from the cold snap in southern China and flooding in Australia have yet to be fully quantified.

Finally, there is the opportunistic buying by China, India and Egypt at the current low prices to build up their reserves. Industrial users of sugar are also in the game. “As buying picks up, quarterly raw trade balances will sporadically tighten, and prices could rise as a result.” •

Third quarter in 2013 may see sugar prices bouncing back says Macquarie THE PEOPLE

BEHIND SUGAR

YEARS Of OPERATIONAL ExPERIENcE SUPPORTED BY A DEDIcATED R&T TEAm HAvE mADE TATE & LYLE PROcESS TEcHNOLOGY SYNONYmOUS wITH INNOvATIvE SOLUTIONS fOR SUGAR REfINERIES AND fAcTORIES. wE PROvIDE THE vERY HIGHEST STANDARD Of cONSULTANcY, DESIGN AND TEcHNOLOGY fOR NEw-BUILD PROjEcTS AND UPGRADES. fOR GUARANTEED wORLD-cLASS PERfORmANcE, PRODUcTION vOLUmES, PRODUcT qUALITY AND ENERGY EffIcIENcY, wITH A REDUcED ENvIRONmENTAL fOOTPRINT – AND mOST ImPORTANTLY, PEAcE Of mIND – TALk TO US, THE PEOPLE BEHIND SUGAR.

www.tlpt.co.uk T +44 (0)20 7540 1769

T&L Process Technology Ltd Thames Refinery factory Road, Silvertown London, E16 2Ew United kingdom

TLPT_ISJ_AD_190x134_OCT_AW.indd 1 26/09/2011 11:55


Industry NEWS For the latest sugar industry news go to: www.internationalsugarjournal.com

A state judge stopped a ban on restaurants, delis and other businesses in New York from selling large sugary drinks on 11th March, one day before they were to take effect.

Echoing the complaints of consumers and small-business owners that the rules were practically unworkable and unenforceable, suffused as they were with loopholes and exemptions, Justice Milton A. Tingling Jr. of State Supreme Court in Manhattan, stated in critical tone in the 37-page judgement that “It is arbitrary and capricious because it applies to some but not all food establishments in the city, it excludes other beverages that have significantly higher concentrations of sugar sweeteners and/or calories

on suspect grounds, and the loopholes inherent in the rule, including but not limited to no limitations on refills, defeat and/or serve to gut the purpose of the rule.”

Mayor Bloomberg who undertook a multi-million dollar campaign to address the issue of obesity, which included flying banners from airplanes and subway stations plastered with advertisements, said that he would immediately appeal to the ruling.

Mr Bloomberg was forthright on the proposed ban which would have limited the size of the sugary to drinks to 16 ounces at restaurants, theatres and other businesses. He stressed “We believe that the judge’s decision was clearly in error, and we believe we will win on appeal.”

The plan against sugary drinks was unveiled last May, and other cities in US, in particular Los Angeles and Cambridge, Massachusetts were pursuing similar bans.

A spokesman for the American Beverage Association welcomed the ruling. Its spokesman was quoted by New York Times as saying “With this ruling behind us, we look forward to collaborating with city leaders on solutions that will have a meaningful and lasting impact on the people of New York City”.

In his ruling, Justice Tingling broadly agreed with beverage industry’s legal arguments. He said that the Board of Health, appointed by the Mayor had overstepped their bounds for approving the plan. “The rule

would not only violate the separation-of-powers doctrine, it would eviscerate it,” Tingling wrote. “Such an evisceration has the potential to be more troubling than sugar-sweetened drinks.”

Further, the judge pointed out that the Mayor’s plan applied only to certain sugared drinks - dairy-based beverages, like milkshakes, for example, would be exempt, with the proviso that certain establishments like restaurants and delis would have to observe the enforcement, but not others, like convenience stores and bodegas. The judge stated that under these circumstances, the rules would result in “uneven enforcement, even within a particular city block, much less the city as a whole.” •

USA - Proposed ban on big sugary drinks in New York, dismissed by judge

ABF Sugar recently announced that it is “mothballing” two of its smallest beet sugar factories in north China due to decline in sugar prices impacting profitability.

“As a result of much lower sugar prices our operations in China will be loss-making this year. It is anticipated that sugar prices will continue at this level for some time and we have sought to reduce our cost base” Associated British Foods said, in a trading update for the six months to early March, the first half of the group’s financial year.

“At the end of this campaign, the small beet factories at Wangkui and Baolongshan have been mothballed,” the group

said, revealing a £22 million charge against the closures.

This measure by ABF Sugar reflects the particular dynamics of a Chinese market in which domestic prices, while well below 2011 highs, remain above world market prices, propped up by government measures to support the domestic industry.

Chinese sugar production costs are estimated to be 30 cents per pound compared with around 18 cents for Brazil, which is similar to current New York futures prices, the world benchmark.

The relatively high domestic prices are fuelling sugar imports, sometimes illegal, at levels far exceeding initial market expectations. •

ABF Sugar “mothballing” two beet sugar factories in China

The Economic Coordination Committee (ECC) of the Cabinet recently approved inland freight subsidy of Rs1.75 per kg (U$18/tonne) for the export of 1.2 million tonnes of sugar, reported The Express Tribune.

The ECC was chaired by the Federal Finance and Economic Affairs Minister, Saleem Mandviwalla.

The move came in the wake of slow pace of sugar export and the need to improve the industry’s liquidity position to help facilitate payment to cane growers.

This is the second support to the sugar industry by the government in the space of two months, as the government has already provided Rs8 billion in tax relief by lowering federal excise duty to 0.5%.

The ECC also endorsed the “Framework for Power Cogeneration 2013 (Bagasse/Biomass)” for inclusion in the Renewable Energy Policy 2006. This framework will be for all high-pressure cogeneration projects utilising bagasse and biomass.

The Renewable Energy Policy 2006 was also extended for five years. •

Pakistan - Government approves freight subsidy for sugar export

INTERNATIONAL SUGAR JOURNAL 2013, VOL. 115, NO. 1372

For the latest sugar industry news go to: www.internationalsugarjournal.com

Engineers & Contractors

Brussels • BelgiumTel.: +32 (0)2 634 25 00Fax: +32 (0)2 634 25 25

E-mail: [email protected]

www.dsengineers.com

Reliability through Experience

Sugar PlantSugar Refi nery

Bioethanol PlantCogeneration Plant

From Basic Engineering to

Full Turnkey Project

Single Point Responsibility through EPC or EPCM+© with guaranteed:

✔ Process Performances✔ Time Schedule

✔ Budget

pub-sugar-103x297.indd 1 10/01/11 12:55

Dalmia Bharat Sugar Industries Ltd is to invest Rs210 crore (U$38.6 million) to double the crushing capacity of its plant in Kolhapur to 5,000 tonnes crushed per day (tcd) by end-December reported The Hundu Business Online.

Speaking to reporters, B.B. Mehta, Director and CEO, Dalmia Bharat Sugar said that the company is also setting up a 23-MW bagasse and coal-based co-generation plant as part of the expansion plans.

The investment is funded through a term loan from banks and the rest from internal accruals, Mehta said.

Dalmia had acquired the

stressed assets of a sugar co-operative in Kolhapur in an auction last year for Rs 135 crore (U$24.8 mllion) and has restarted the acquired plant in the current sugar season.

Total expansion cost in Kolhapur is estimated at Rs 345 crore (U$63.4 million) for which the company has tied-up for term loan worth Rs 220 crore (U$40.4 million).

Mehta expects the company’s sugar output in the current 2012-13 season to increase to 300,000 tonnes from 240,000 tonnes in the previous year. Dalmia Bharat operates three sugar factories in Uttar Pradesh with a total crushing capacity of 22,500 tcd.•

India - Dalmia Bharat Sugar to invest U$38.6 million to expand capacity of its Kolhapur unit

Kakira Sugar Limited recently installed a new cogen unit that will significantly increase its power generation capacity at its factory.

Speaking to New Vision, Kakira’s managing director, Mayur Madhvani, said that the $65m investment in the new plant at the factory will result in power output increasing to 52MW in July this year up from the current 22MW with the existing unit at the factory.

Mayur told New Vision that the factory currently sells 14MW to the national grid. “By mid-March Kakira will be

generating 32MW and will be selling 22MW to the national grid. In July this year we will generate 52MW and sell 32MW to the grid on a regular basis,” Mayur said.

Expansion of the cogen unit will coincide with expansion in sugar production. The factory will be crushing two million tonnes of cane annually. Of these, the out-growers will supply 1.40 million tonnes of cane and the balance of 600,000 tonnes will come from the company’s own estate. This will support the production of 180,000 tonnes of sugar, Mayur said. •

Uganda - Kakira Sugar installs new cogen unit that will generate 52MW



Of the 330 sugar/ethanol plants in central-southern Brazil, accounting for 90% of all the sugar cane processed in the country, likelihood is that 60 will probably close down over the next two to three years, according to Industry Union Cane (UNICA), reported Exame.com. Further, UNICA confirmed that at least ten mills are unlikely to process cane in 2013/2014, due to financial difficulties.

Following the credit crunch in 2008, with access to cheap capital drying up and rise in interest rates, new build activity in the sector has slowed down considerably. In contrast, 36 plants have gone

into bankruptcy protection over the five years. Worse, during the past two year some 43 plants were closed.

Antonio de Padua Rodrigues, technical director of UNICA, was candid about some of the underlying issues contributing to the decline. He pointed out that the combination of mismanagement and loss of agricultural productivity was exacerbated by inclement weather and the drive towards mechanization (for planting and harvesting operations in particular) sapped capital and contributed to significant increase in production costs.

To make matters worse, on the hand, with gasoline price artificially low, ethanol

production for the local market has not been competitive, and increasing global surplus has decreased world sugar price over the past two years by 39%. Effectively therefore, rising costs and squeezed margins has resulted in increased debt.

Despite the recent increase in wholesale gasoline price by 6.6% by the government which has resulted in an increase in pump price by 4.2-5.3%, this appears to be too little and too late.

According to a survey by the investment bank Itaú BBA, the current level of industry debt in centre-south is around Reals 56 billion and set to rise by further 4 billion next year. Alexandre Figliolino from the bank has confirmed

that one-third of this sector is experiencing difficulties. He divides the sector into four distinct groups. The first, consisting of mainly international companies, with full access to capital, and the second, large national companies who continue to perform well. The problem is, he says, is with the remaining two groups, which are essentially family owned plants, comprising over 45% of the sector.

An informed source, an experienced sugar analyst, doubts the extent of mill closures, as the industry has recently made significant strides in increasing cane production and productivity. The perception being that the industry is turning around. •

Some 60 sugar mills in centre-south Brazil face probable closure during 2013/2014

Germany’s sugar beet har-vest has now ended and earlier forecasts of a slight fall in sugar production in the current 2012/13 season are likely to be confirmed, said Guenter Tissen, chief executive of the country’s sugar industry association WVZ.

“We do not have final harvest figures yet but our last forecast was for a reduction in refined sugar output to around 4.4 million tonnes or a fall of about 0.3 million tonnes compared to the previous season,” Tissen said.

Final production figures are expected in April. Germany is in most seasons the EU's

second largest sugar producer after France.

“Harvesting is now over and work progressed generally satisfactorily,” he said. “We had some minor problems in north east Germany where several thousand tonnes of beets could not be processed in refineries.”

Some sugar beets harvested had been damaged by changes between frosts and warm weather, he said.

Beet yields were also generally lower than the previous season, he said.

German farmers had planted 393,000 ha of sugar beet for the 2012/13 crop just harvested, little changed on the 394,000 ha harvested last

season. However, farmers had warned last summer that dry weather had not been favourable to beets.

German sugar output of 4.4 million tonnes would, as in past years, mean the country would exceed its EU production quota of some 2.8 million tonnes, this time by about 1.5 million tonnes.

The EU restricts output of some crops such as sugar with quotas. Sugar output over the EU quota cannot normally be sold as food or exported but may be marketed for industrial use in the production of chemicals or ethanol.

Germany also produced well over its EU production

quota in previous seasons. Much of its out-of-quota sugar in the past has been used for ethanol production.

Tissen said he also expected ethanol production to be a major outlet for non-quota sugar from this winter's crop, along with possible exports. The EU has permitted exports of 1.3 million tonnes of out-of-quota sugar.

It was also possible that part of the 1.5 million tonnes would be held over into the new season as quota sugar, he said. “This would mean producers will have sugar in store and will consider this when making planting recommendations to farmers,” he added. •

Germany - Slight fall in sugar output forecast

Find more stories on-line by visiting ISJ’s website at:internationalsugarjournal.com


Industry NEWSFor the latest sugar industry news go to: www.internationalsugarjournal.com

a Smart Eye

Color AnalyzerColobserver ®

Track Sugar Production in real-timeManage your sugar color and quality

Record video sequences on eventsOptimize centrifugal washing timeDetect out-of-specification sugar

Increase productivity and profitabilityReduce water and power consumption

Control Crystallization in real-timeFollow crystal growth in the panImprove crystallization processMeasure crystal sizes (from 4 µm)Keep video records of the processTrigger out-of-specification alarmsAcquire valuable statistical information

Pan MicroscopeMCC3000

www.iteca.fr - [email protected]: +33 (0) 442 977 700

According to a new mar-ket report published by Transparency Market Research sorbitol demand was 1,699.7 kilo tons in 2011 and is expected to reach 2,148.9 kilo tons in 2018, growing at a CAGR of 3.4% from 2012 to 2018.

Sorbitol is being increasingly explored as a platform chemical for the production of polyols such as ethylene glycols, propylene glycols and glycerols which are predominantly derived from petrochemicals. Sorbitol's product base is more or less the same as compared to polyols and isosorbides. Thus, the increasing application scope for polyols and isosorbides provides

significant potential for sorbitol downstream processing.

Key products analyzed and estimated in this study include liquid/syrup and crystal/powder sorbitol. Liquid sorbitol presently dominates the product market and accounted for 83.3% of the overall demand in 2011. Key applications analyzed and estimated in this study include toothpaste, Vitamin C, diabetic & dietetic F&B and surfactants. Diabetic & dietetic F&B and toothpaste are key applications for sorbitol and accounted for 23.6% and 21.3% of the overall demand in 2011. Vitamin C application follows diabetic & dietetic F&B and toothpaste and in terms of volumes, is expected to grow at a CAGR of

3.5% from 2012 to 2018.In terms of consumption,

Asia Pacific dominates the global market and accounted for over 50% of the overall demand in 2011, this demand is mainly distributed across China, Japan, India and Indonesia. Increasing demand for low calorie sweeteners, especially from the U.S. and the European Union is expected to drive sorbitol demand over the next five years. European sorbitol revenues are expected to grow at a CAGR of 12.5% from 2012 to 2018. However, product pricing has emerged as a key challenge to the industry, with bulk prices soaring by over 20% from the 2010 levels. Price fluctuations have primarily been caused by poor weather

forecasts and tight inventories owing to the rising demand in increasing applications across various domains. Recent volatility in basic raw material prices in recent times has emerged as a critical challenge for this market.

Key market participants profiled in this report include Archer Daniels Midland, Roquette Freres, Cargill Inc, Ecogreen Oleochemicals, SPI Pharma, Sigma- Aldrich, Gulshan Polyols and Sorini.

The report is titled “Global Sorbitol Market - Isosorbide, Propylene Glycol, Glycerol & Other Downstream Opportunities, Applications (Toothpaste, Vitamin C, Sweetener etc.), Size, Share, Growth, Trends and Forecast, 2012-2018.” •

Global sorbitol market to grow at a CAGR of 3.4%


Recovery and cane payment

Moberly (1935) considered cane

payment as “primitive” if cane

quality and/or factory recovery

were not considered. These add

to the complexity of a system

involving cane weighing and

tracking, sampling and analyses,

activities which themselves are

far from simple. Nevertheless a

number of approaches have been

developed for factories producing

sugar and molasses only. An

accepted principle is that fibre

and non-pol remove pol through

bagasse and final molasses

respectively; Saranin (1975)

describes a number of approaches

to quantify this. Here we will

assume that “pol” and “sucrose”

are equivalent.

Commercial Cane Sugar, CCS,

was proposed in 1888 by Kotmann

and adopted in Australia in 1915

(Saranin). Pol and Brix % FEJ and

fibre % cane are determined and

used to calculate CCS:

where P, B and F are pol, Brix

and fibre % cane. P and B are

given by:

Hugot (1974) discusses the

press method used in Reunion

Island. Saranin shows that the

recoverable sugar, SR, is given by:

where s and p are pol % and

purity of the press juice; f is the

unit fraction of fibre % cane which

is obtained by using a relation

established previously between the

weight of the press cake and fibre

% cane by the bag method, under

the pressing conditions used.

van Hengel (1974) proposed

the ERC formula giving the

crystallisable pol in cane:

where P, N and F are the pol, non-

pol and fibre % cane respectively.

a, b and c are factors calculated

using averaged industrial data;

a represents the unit fraction of

pol in sugar, undetermined loss

and bagasse; b is the unit fraction

of pol in molasses per unit of

non-pol in cane; c is the loss of

pol in bagasse per unit of fibre in

cane. Here +0.98, -0.46 and -0.05

have been selected for a, b and c

respectively.

The effects of P, B and F

on CCS, SR and ERC, other

conditions being as comparable as

possible, are illustrated opposite.

“Average” impacts of P, B

and F on CCS, SR and ERC are

compared below; in each case the

data in the graphs have been used

to estimate the change caused by

a 1 unit increase in P, B or F. As

can be seen CCS, SR and ERC

respond differently.

% change for a 1 unit increase in

P B F

CCS +12% -4% -2%

SR +15% -7% -0.3%

ERC +8% -4% -0.4%

Cane payment is a sensitive

topic and can be highly

complicated. For example a

seasonal factor may be used to

compensate growers delivering

cane outside the peak cane

maturity period; in other cases

adjustments are made at the end

of the season due to changes in

the price of sugar. In South Africa

the tonnages of pol and Brix in

cane can be calculated from the

direct analysis of cane (DAC) and

from mass balances (e.g. Tons P

in cane = Tons P in mixed juice +

Tons P in bagasse); adjustments

may be made if the two results do

not agree. It is possible to convert

pol to true sucrose to obtain more

accurate balances.

Recently near infra-red (NIR)

spectroscopy has been introduced

to analyse cane and other streams

on line; this technique will allow new

developments for cane payment.

Finally the SJM formula, one

of the most famous in sugar

technology, is also relevant here;

this will be discussed in the next

Blackboard. •

References

Hugot, E. (1974) Direct analysis

and evaluation of sugar cane.

Proc. ISSCT.

Moberly, G.S. (1935)

Fundamental principles of cane

payment. Proc. ISSCT.

Saranin, A.P. (1975) Sugar

cane payment systems. Sugar

Technology Review 3: 155-238.

van Hengel, A. (1974) Proposal

for the evaluation of cane and sugar

in identical units at standardised

factory efficiency. Proc. ISSCT.

THE BLACKBOARDby Raoul Lionnet Email: [email protected]

CCS%C = 3P 1 − F+5 − B 1− F+3 2 100 2 100( () )

P = Pol%FEJ x 100 − (F+5) 100

P = Brix%FEJ x 100 − (F+3) 100

( )SR = 0.83s x (1 − f ) − 5f + 102.5 − p 100

ERC%C = a x P − b x N − c x F



Biofuels NEWS



INTERNATIONAL

Researchers from The University of Texas at Arlington are pioneering a new method for using carbon dioxide to make liquid methanol fuel by using copper oxide nanowires and sunlight.

The process is safer, simpler and less expensive than previous methods to convert the greenhouse gas associated with climate change to a useful product, said the lead researcher, Krishnan Rajeshwar.

Researchers began by

coating the walls of copper oxide, CuO, nanorods with crystallites made from another form of copper oxide, Cu2O. In the lab, they submerged those rods in a water-based solution rich in CO2. Irradiating the combination with simulated sunlight created a photoelectrochemical reduction of the CO2 and that produced methanol.

Two types of copper oxide were selected because both are photo active and they have complementary solar light absorption.

In contrast, current methods require the use of a co-catalyst and must be conducted at high operating pressures and temperatures. Many also use toxic elements, such as cadmium, or rare elements, such as tellurium, Rajeshwar said.

The experiments generated methanol with 95% electrochemical efficiency and avoided the excess energy input, also known as overpotential, of other methods.

Other than fuel, methanol

is used in a wide variety of chemical processes, including the manufacturing of plastics, adhesives and solvents as well as waste-water treatment. In the United States, there are 18 methanol production plants with a cumulative annual capacity of more than 2.6 billion gallons, according to the paper.

The research is published in a recent issue of Chemical Communications as well as in Chemical and Engineering News. •

Efficient carbon dioxide to methanol production process advanced

In the search for renewable alternatives to gasoline, heavy alcohols such as isobutanol are promising candidates. Not only do they contain more energy than ethanol, but they are also more compatible with

existing gasoline-based infrastructure. For isobu-tanol to become practical, however, scientists need a way to reliably produce huge quantities of it from renewable sources.

Commercial scale

production of isobutanol continues to be a challenge. Recently, MIT chemical engineers and biologists have devised a way to dramatically boost isobutanol production in yeast, which naturally make it in small amounts.

They engineered yeast so that isobutanol synthesis takes place entirely within mitochondria, cell structures that generate energy and also host many biosynthetic pathways. Using this approach, they were able cont. over…

Yeast bioengineered to yield high output of isobutanol


Biofuels NEWS For the latest sugar industry news go to: www.internationalsugarjournal.com

to boost isobutanol production by about 260%.

Though still short of the scale needed for industrial production, the advance suggests that this is a promising approach to engineering not only isobutanol but other useful chemicals as well, says Gregory Stephanopoulos, an MIT professor of chemical engineering and one of the senior authors of a paper describing the work in the Feb. 17 online edition of Nature Biotechnology.

“It’s not specific to isobutanol,” Stephanopoulos says. “It’s opening up the opportunity to make a lot of biochemicals inside an organelle that may be much better suited for this purpose compared to the cytosol of the yeast cells.”

Historically, researchers have tried to decrease isobutanol production in yeast, because it can ruin the flavour of wine and beer. However, “now there’s been a push to try to make it for fuel and other chemical purposes,” says Jose Avalos, the paper’s lead author.

Yeast typically produce isobutanol in a series of reactions that take place in two different cell locations. The synthesis begins with pyruvate, a plentiful molecule generated by the breakdown of sugars such as glucose. Pyruvate is transported into the mitochondria, where it can enter many different metabolic pathways, including one that results in production of valine, an amino acid. Alpha-ketoisovalerate (alpha-KIV), a precursor in the valine and isobutanol biosynthetic pathways, is made in the mitochondria in the first phase of isobutanol production.

Valine and alpha-KIV can be transported out to the cytoplasm, where they are converted by a set of enzymes into isobutanol. Other researchers have tried to express all the enzymes needed for isobutanol biosynthesis in the cytoplasm. However, it’s difficult to get some of those enzymes to function in the cytoplasm as well as they do in the mitochondria.

The MIT researchers took the opposite approach: They

moved the second phase, which naturally occurs in the cytoplasm, into the mitochondria. They achieved this by engineering the metabolic pathway’s enzymes to express a tag normally found on a mitochondrial protein, directing the cell to send them into the mitochondria.

This enzyme relocation boosted the production of isobutanol by 260%, and yields of two related alcohols, isopentanol and 2-methyl-1-butanol, went up even more - 370 and 500%, respectively.

There are likely several explanations for the dramatic increase, the researchers say. One strong possibility, though difficult to prove experimentally, is that clustering the enzymes together makes it more likely that the reactions will occur, Avalos says.

Another possible explanation is that moving the second half of the pathway into the mitochondria makes it easier for the enzymes to snatch up the limited supply of precursors before they can enter another metabolic pathway.

“Enzymes from the second phase, which are naturally out here in the cytoplasm, have to wait to see what comes out of the mitochondria and try to transform that. But when you bring them into the mitochondria, they’re better at competing with the pathways in there,” Avalos says.

The findings could have many applications in metabolic engineering. There are many situations where it could be advantageous to confine all of the steps of a reaction in a small space, which may not only boost efficiency but also prevent harmful intermediates from drifting away and damaging the cell.

The researchers are now trying to further boost isobutanol yields and reduce production of ethanol, which is still the major product of sugar breakdown in yeast.

“Knocking out the ethanol pathway is an important step in making this yeast suitable for production of isobutanol,” Stephanopoulos says. “Then we need to introduce isobutanol synthesis, replacing one with the other, to maintain everything balanced within the cell.” •

Yeast bioengineered to yield high output of isobutanol cont.

Despite the fact that 2012 was challenging for America’s farm economy, domestic ethanol production reached an estimated 13.3 billion gallons.

According to analysis conducted by Cardno- ENTRIX and commissioned by the Renewable Fuels Association (RFA), the production of the estimated

13.3 billion gallons of ethanol directly employed 87,292 Americans. An additional 295,969 Americans found work in positions indirectly affiliated with or induced by ethanol production.

These 383,260 total jobs helped create $30.2 billion in household income and contributed $43.4 billion to the national Gross Domestic

Product (GDP).Last year’s ethanol

production helped displace 465 million barrels of imported oil worth $47.2 billion. This was roughly equivalent to 12% of crude oil imports.

Bulk of the production cost of ethanol was related to feedstock cost. At the operating cost of $2.95/gallon, $2.49 was for corn - that is over 84%. •

US ethanol industry created over 380,000 jobs and $43 billion in GDP

Find more stories on-line by visiting ISJ’s website at:

internationalsugarjournal.com


For the latest sugar industry news go to: www.internationalsugarjournal.com

For Your ETHANOL Projects

|India |The Netherlands |South Africa |USA | UAE | Thailand |

Get the Single Point Advantage

Researchers from US and China have successfully produced gasoline, diesel and jet fuel by thermo-chemical conversion of duckweed, a fast-growing floating plant that turns ponds and lakes green The research is reported in the journal Industrial & Engineering Chemistry Research (2013, DOI: 10.1021/ie3034703).

Christodoulos A. Floudas, Xin Xiao and colleagues explain that duckweed, an aquatic plant that floats on or near the surface of still or slow-moving freshwater, is ideal as a raw material for biofuel production. It grows fast, thrives in wastewater that has no other use, does not impact the food supply and can be harvested more easily

than algae and other aquatic plants. However, few studies have been done on the use of duckweed as a raw material for biofuel production.

They describe four scenarios for duckweed refineries that use proven existing technology to produce gasoline, diesel and kerosene. Those technologies include conversion of biomass to a gas; conversion of the gas to methanol, or wood alcohol; and conversion of methanol to gasoline and other fuels. The results show that small-scale duckweed refineries could produce cost-competitive fuel when the price of oil reaches $100 per barrel. Oil would have to cost only about $72 per barrel for larger duckweed refiners to be cost-competitive. •

Duckweed - A promising feedstock for biofuels production

Cellulosic biofuels produc-tion which has yet to be produced in commercial scale, is likely to do so by 2015, according to the chief executive of producer Beta Renewables speaking to Reuters recently.

The United States produced just 20,000 gallons of so-called cellulosic biofuel last year, according to the U.S. Energy Information Administration. That was a mere 0.04% of a 500-million-gallon target the U.S. government set in 2007.

Beta Renewables opened its first plant in Italy in the final quarter of last year and sees 2013 as a turning point for the industry as demand surges and more production

comes online.Chief Executive, Guido

Ghisolfi, told Reuters he expects the industry to produce around 30 million gallons of cellulosic biofuel from the United States and Europe this year. Commercial production at Beta’s Crescentino plant in the Piedmont region of Italy should reach 15-16 million gallons of this year, he said.

By the end of 2014, Ghisolfi expects six or seven plants to be operating globally across the industry, with output reaching 100 million gallons. “The boom year will be 2015 with 15 to 20 plants producing hundreds of cont. over…

Beta Renewables leads commercial scale production of cellulosic biofuels


A recently published state of the market report by Lux Research predicts that while many companies involved in the production of advanced biofuels will generate real revenue in 2013, there will be those that are doomed to fail.

“Several expensive next-

generation plants expected to come online, the outlook is poised to dramatically change for budding fuel developers and major corporations alike,” said Andrew Soare, analyst and the lead author of the report. “For this industry to actually move the needle on the fuel mix, it needs revenue - or else plants number two,

three and beyond will never materialize.”

The report, which is titled “Leading Alternative Fuel Developers Race to Real Revenue in 2013,” examines 156 companies in eight fields: crop modifiers, pretreatment, algae, gasification, bioprocessing, pyrolysis, torrefaction and catalytic conversion.

In the pretreatment category, Lux Research identified 21 key players working on biomass-to-sugars technology. At the top of the list were Beta Renewables and its partner Novozymes, companies considered to be dominating the pretreatment space. Other dominant players include Dyadic International, Codexis, Renmatix, Blue Fire Renewables, REAC Fuel and Virdia. Sweetwater Energy and Cellulose Sciences were two companies named as having high potential while Iogen, Blue Sugars, Inbicon and EdeniQ were considered to be undistinguished.

The report put gasification technology developer Enerkem into the dominant category while Fulcrum BioEnergy was categorized as a long shot, despite the award of a $105 million USDA loan for its $180 million 10 MMgy ethanol plant. Gasification of municipal solid waste and waste biomass has drawn the attention of developers, investors and government agencies. “But this distinguishing attribute comes only to those willing to wager with a hefty capital infusion,” the report said. “Range Fuels’ $300 million letdown that ended in a sorry

liquidation illustrates the realistic scenario investors mull over.”

There are alternative fuel bioprocessing companies with momentum and maturity, the report said. Of the 30 analyzed, 13 were considered dominant, including Gevo, Solazyme, and Poet LLC, at the top. Of those 30 companies, 14 listed ethanol as the main product or one of the main products to be produced. Four of the companies were targeting butanol, with Gevo considered more mature and positive than competitor Butamax, which was judged as dominant but with a wait and see qualifier. The two other butanol companies listed were Cobalt Technologies, dominant, and Phytonix Corporation, a long shot.

Of the key players in the crop modification arena, Agrivida Cellulosic, a company working on engineered biomass to produce fuels, chemicals and animal feed, was categorized as dominant. ArborGen, which is working on breeding and genetic modification of trees, and Leaf Energy, a plant-based platform for producing enzymes/molecules for biofuels and other applications, were named as high potential.

The algae companies face dim prospects, the report said. A total of 29 algae companies were studied, with 23 considered to be long shots. Algae Tec barely qualified as dominant, the only company in this sector to achieve that rating.•

Many advanced biofuels company will begin to generate revenues in 2013 says Lux Research

Biofuels NEWS For the latest sugar industry news go to: www.internationalsugarjournal.com

millions of gallons,” Ghisolfi said.

Beta’s Crescentino plant is the world’s first commercial-scale cellulosic ethanol facility. Feedstocks used will depend on season and includes wheat straw, rice straw, arundo, eucalyptus and poplar.

Beta was created in 2011 through a joint venture between polymer producer M&G Group’s engineering division, Chemtex, and investment firm TPG. Chemtex owns a 67.5% stake, TPG has 22.5% and Danish biotechnology company Novozymes last year took a 10% stake for $115 million.

Chemtex also plans a 20 million gallon per year cellulosic ethanol facility in North Carolina using Beta Renewables technology which should be up and running by the end of next year.

Beta Renewables has signed two licences with companies who want to use its technology to build plants, one with Brazil’s GraalBio and one with Colbiocel in Colombia.

The firm expects to sign 10 more licences this year

and more than 20 next year, Ghisolfi said.

“Capital expenditure is not the risk anymore. The technology is there to be seen. The only risk left is the availability of the biomass,” he said.

The availability of biomass could be one reason why the United States is slow to lead the market, Ghisolfi said. The cost of the cellulosic biofuel produced in the United States is likely to be higher than elsewhere because it could be limited in the type of biomass feedstock that can be used.

“There are more plants being built in the United States but cost-wise it will not be at the front. For that, Brazil will be the frontrunner and Southeast Asia is immediately behind,” Ghisolfi said.

In Europe, Ghisolfi expects to see three to four plants in Germany, Italy, Spain, Britain and France devoted to specific types of biomass in the near future. He expects new players to emerge in eastern Europe over the next year. •

Beta Renewables leads commercial scale production of cellulosic biofuels cont.


Biobased Products NEWS



INTERNATIONAL

principal

principac

up to bags per hour2400

up to

bags per hour2000

High-speed packaging systems

High-speed palletizing systems

STATEC BINDER GmbH, Industriestrasse 32, 8200 Gleisdorf, Austria, Tel.: +43 3112 38580-0, [email protected]

www.statec-binder.com

High-speed packaging machines

Compact design

Free flowing bulk products

Pillow bags and gusseted bags

Form, fill & seal machines

Global production capacity of biobased polymers is forecast to more than treble from 3.5 million tonnes currently to nearly 12 million tonnes in 2020, according to the Germany-based Nova Institute.

The figures suggest that the biobased share of total polymer production in 2020 - around 400 million tonnes - should increase from 1.5% in 2011 to 3% in 2020, suggesting that biobased production capacity

will grow faster than overall production.

According to Nova the most dynamic development is foreseen for drop-in biopolymers, which are chemically identical to their petrochemical counterparts but at least partially derived from biomass.

This group is spearheaded by partly biobased PET (Bio-PET) whose production capacity will reach about 5 million tonnes by the year 2020, using bioethanol

from sugarcane.The second in this group

are biobased polyolefins like PE and PP, also based on bioethanol. But ‘new in the market’ biobased polymers PLA and PHA are also expected to at least quadruple the capacity between 2011 and 2020.

Nova argues that most investment in new biobased polymer capacities will take place in Asia and South America because of better access to feedstock

and a favourable political framework.

Europe’s share will decrease from 20% to 14% and North America’s share from 15% to 13%, whereas Asia’s will increase from 52% to 55% and South America’s from 13% to 18%. World market shares are not expected to shift dramatically, suggesting every region will experience development in the field of bio-based polymer production. •

Biopolymer production to treble by 2020


Biobased Products NEWS For the latest sugar industry news go to: www.internationalsugarjournal.com

Cereplast, leading manu-facturer of proprietary biobased, compostable and sustainable bioplas-tics, recently announced that three dozen Indian companies are currently testing Cereplast bioplastic resins, including Cereplast Compostables® resins and Cereplast Biopropylene® grades for a variety of different applications.

Compostable applications include blow-moulded water bottles, blown film garbage bags and single-use grocery bags by companies including Jeevan Polymers of

Hyderabad, Andhra Pradesh and Back to Compost of Mumbai, Maharashtra. Durable, Biopropylene applications include industrial products, electrical tubing, helmets, bottles and caps, reusable non-woven bags, buckets, dishes, furniture and other household items by companies including Saraswati Plastics, Sachin Plastics, Jain Plastic Corporation and Sri Sai Vishwas Industries of Hyderabad, Andhra Pradesh.

Feedstocks used by Cereplast to produce bioplastic resins include corn, tapioca, potatoes and sugar. •

Cereplast expands into the Indian market

USDA’s Agricultural Research Service (ARS) scientists have created a biodegradable plastic made from sugar beet pulp

Using a process called extrusion, the ARS scientists combined sugar beet pulp with a commercially available biodegradable polymer called polylactic acid (PLA) to create a new “thermoplastic,” a plastic that becomes soft when heated. Extrusion is already used widely in large-scale production of food, plastics and composite materials, and it’s very cost-effective.

The scientists say we could use this new thermpolastic to make those soft, white, spongy containers that are a perfect holder for use in fast food joints.

America’s sugar industry

produces up to a million ton annually of beet pulp which can be diverted for use in the new product. The PLA can be made from sugars in corn, sugarcane, switchgrass and other renewable feedstocks. The ARS scientists say you can use up to 50% sugar beet pulp in the thermoplastic mixture and still get a finished product with properties similar to those of polystyrene and polypropylene, the compounds now used to make food containers.

Further, the scientists can combine the sugar beet pulp with water or glycerol to create a different type of thermoplastic that could find a new life as yogurt cups, cottage cheese tubs, and bags. In that formulation, the recipe could be up to 98% sugar beet pulp. •

Thermoplastics created with sugar beet pulp

Lignol Innovations Ltd. (LIL) recently announced that it has secured a commercial supply agreement with a European company producing sustainable thermoplastics. The agreement provides for the supply of LIL’s proprietary HP-LTM lignin by the ton.

In the production of cellulosic biofuels, around 25% of the output from treating lignocellulosic feedstocks is lignin. “Companies can burn the lignin for its calorific value of approximately five cents a pound, or utilize Lignol’s technology to realize values of 50 cents to $2 per pound as a substitute for certain petroleum-based inputs in a variety of applications, such as resins, binders,

coatings, carbon fiber and thermoplastics” said President and Chief Executive Officer, Ross MacLachlan.

Lignol has teamed with Novozymes to optimize the use of Novozymes’ enzymes in Lignol’s cellulosic biofuel process at the company’s 100,000 liter-per-year (26,417 gallon) pilot plant in Burnaby, British Columbia, Canada. Last September, the companies announced they had improved performance by 35% from previously best-achieved results. The company uses a modified solvent-based pretreatment technology that it says facilitates the rapid, high-yield conversion of cellulose to ethanol and the production of high-value co-products such as lignin.•

Lignol to supply purified lignin to thermoplastics producer

Zeon Chemicals recently announced that it has begun producing Hydrin-brand elastomers at its plant in Hattiesburg, Mississippi using epichlo-rohydrin monomer derived from palm and other vegetable oils.

Biobased content of the synthetic rubber is around 20-25%, stressed Clark Cable, Hydrin Business Manager.

Specific characteristics of the Hydrin line are claimed to include: broad temperature range, from

-40°C to >125°C continuous; >150°C short-term; range of dynamic properties - damping to resilient; inherently electrostatic dissipative; very permeation resistant to gases - exceeds butyl in most instances; and hydrocarbon resistant - fossil and biofuels

This range of characteristics supports its use in a wide range of applications, such as automotive hoses, air ducts, diaphragms, laser printer rolls and vibration dampening devices. •

Zeon Chemicals commence production of biobased elastomers

Find more stories on-line by visiting ISJ’s website at:internationalsugarjournal.com


Exactly how a crystal forms from solution is a problem that has occu-pied scientists for decades including those working in the sugar industry. Researchers at Eindhoven University of Technology (TU/e), together with researchers from Germany and the USA, are claiming to have found the missing piece in the understanding of the crystallization process.

This classical theory of crystal formation, which occurs widely in nature and in the chemical industry, was under fire for some years, but is saved now. The

team made this breakthrough by detailed study of the crystallization of the mineral calcium phosphate – the major component of bones. The team recently published their findings in the online journal, Nature Communications.

Crystallization is the formation of a solid ordered substance, such as happens when water freezes. In nature, crystals are mostly formed from ions which are dissolved in water, as for example in the formation of shells or bone. This involves the clustering of ions into increasingly large nuclei, until a crystal is formed when a certain size is reached. However, the details of this growth process have been the subject of discussion for many years.

According to the existing theories, it is individual ions that group together to form crystal nuclei. But in 2009 chemists

led by Nico Sommerdijk (TU/e) showed the presence of an intermediate step in the growth process of calcium carbonate crystals. The ions were thought to first form small clusters, which then grow into crystal nuclei. This finding caused controversy because it appeared to contradict the classical crystallization theories which did not allow for such an intermediate step.

Now Sommerdijk is having second thoughts about his 2009 conclusions. At least, the answer now turns out to be more subtle than was thought at that time. Together with researchers from the Max Planck Institute in Germany and the Lawrence Berkeley National Laboratory in the USA, he looked more closely at the role of these so-called pre-nucleation clusters in the growth process of the mineral calcium phosphate. Using a cryo-electron

TRENDSin science and technology



INTERNATIONAL

Researchers inch towards understanding crystal formation


TRENDS For the latest sugar industry news go to: www.internationalsugarjournal.com

microscope, which makes images of deep-frozen samples, he was able to identify the precise components of the clusters and study the growth process in detail.

In their article in Nature Communications, Sommerdijk concludes that the clusters do not form a clearly defined intermediate step, but instead are part of a gradual growth process. Sommerdijk refers to the formation of clusters as a ‘false start’ by the ions, because the clusters already start to organize themselves step by step while still in solution, without actually forming growth nuclei. This new understanding means the existing theories no longer need to be overturned.

Sommerdijk’s team have now completed the theory by describing alternative ‘pathways’ along which crystals can form. Sommerdijk's new conclusions have since been confirmed in a second study into crystal formation in the mineral magnetite, which was published online this month in Nature Materials.

In Sommerdijk’s view the most important questions about the formation of crystals have now been answered. This theoretical knowledge is important in many fields, because of the widespread occurrence of crystallization in nature and in the chemical industry. Just a few examples are the formation of coral in the sea, the production of pharmaceuticals and the design of nanoparticles. It could for example help to make production processes less costly, faster or more energy-efficient.

Sommerdijk stressed “that what we have found is that there are multiple nucleation pathways possible and that these all can be understood using classical nucleation theory. This means that the theory of nucleation has made another step, i.e. to also include what used to be “non-classical” pathways. The development of theory is crucial to the understanding and eventually prediction of crystallization processes. Once we can predict we can efficiently design optimized processes.”

Researchers from Denmark have made a breakthrough in re-engineering

photosynthesis to transform plants into bio-factories that manufacture high-value ingredients for medicines, fabrics, fuels and other products. Their findings are reported in ACS Synthetic Biology.

Poul Erik Jensen and colleagues at the University of Copenhagen explain that photosynthesis does more than transform carbon dioxide and water into sugar and oxygen and generate energy.

That process also produces a wealth of natural chemical compounds, many of which have potential uses in medicines and other commercial products. However, evolution has compartmentalized those functions into two separate areas of plant cells. Chloroplasts, the packets of chlorophyll that make plants green, generate energy and produce sugar and oxygen. Another structure, the endoplasmic reticulum, produces a wide range of natural chemicals.

Their report describes breaking that evolutionary compartmentalization by relocating an entire metabolic pathway needed for production of natural bioactive chemicals to the chloroplast. “This opens the avenue for light-driven synthesis of a vast array of other natural chemicals in the chloroplast,” they say, citing key natural chemicals that would be ingredients in medications.

Understanding exactly how droplets and bubbles stick to surfaces - every-thing from dew on blades of grass to the water droplets that form on condensing coils after steam drives a turbine in a power plant - is a “100- year-old problem” that has eluded experimental answers, says MIT’s professor, Kripa Varanasi. Further-more, it’s a question with implications for everything from how to improve power-plant efficiency to how to reduce fogging on windshields.

Now this longstanding problem has finally been solved, Varanasi claims, in research published recently in Nature Communications. The researchers achieved the feat using a modified version of a scanning electron microscope in which the dynamic behaviour of droplets on

surfaces at any angle could be observed in action at high resolution.

Previous attempts to study droplet adhesion have been static - using drops of a polymer that are allowed to harden and then sliced in cross-section - or have been done only at very low resolution. The ability to observe the process in close-up detail and in full motion is an unprecedented feat, says Varanasi.

Normally, scanning electron microscopes observe materials on a fixed horizontal stage and under a strong vacuum, which causes water to evaporate instantly. The MIT team was able to adapt the equipment to operate with a weaker vacuum, and with the ability to change the surface angle and to push and pull droplets across the surface with a tiny wire.

The researchers found that a key factor in determining whether a droplet sticks to the surface is the angle of the droplet’s leading and trailing edges relative to the surface. Nobody had been able to observe these angles dynamically at microscale before, while theorists had not predicted their importance.

The MIT researchers also found that on rough surfaces, surface texture is crucial to adhesion. Surprisingly, they found that too much roughness can make droplets stick more - contrary to the widely held belief that greater roughness always improves a surface's ability to shed water. It all depends on the details of the texture, they found.

For many applications, it’s important that droplets fall away from a condensing surface as quickly as possible; for others, it's best to “pin” them in place as long as possible so they can grow and spread. The new analysis, which led to a mathematical system for precisely predicting droplet behaviour, can be used to optimize a surface in either way. (Bubbles, such as those on the bottom of a pan of boiling water, behave in essentially the same way).

“People have only been able to make sketches” of how droplet adhesion works, said Adam Paxson, the co-researcher. With the new high-resolution imagery, it is now clear that as a droplet peels away from a rough surface, the round droplet forms a series of tiny “necks” adhering to each of the high points on the surface; these necks (which the researchers call

Tweaking photosynthesis apparatus to make drugs, compounds or ingredients

Mobility of droplets on surfaces demystified


“capillary bridges”) then gradually stretch, thin and break. The more high spots on the surface, the more of these tiny necks form. “That’s where all the adhesion occurs,” Paxson says.

The researchers say the phenomenon is “self-similar,” like fractal structure: Each neck or capillary bridge can consist of several capillary bridges at finer length scales; it is the cumulative effect that dictates the overall adhesion. This self-similarity is exploited by some biological structures for lowering adhesion.

There had been two leading theories on how to calculate the adhesion of droplets: One held that the areas of contact and energy levels of the molecules were key; the other, that the length of the edge of a drop on a surface was critical. The evidence produced by this research strongly supports the second theory. “I think we have now closed a decades- old debate on this one,” Varanasi says.

In general, Paxson says, “complicated shapes tend to be more sticky,” because of their greater edge-length.

Droplets and bubbles are ubiquitous in many engineering applications. This work could be applied to engineering industrial surfaces with controlled adhesion in applications ranging from large desalination and power plants to consumer products such as fabrics, packaging and medical devices. While some applications, such as condensers, strive to shed droplets quickly from a surface, others - such as ink droplets sprayed onto paper in an inkjet printer - require the reverse. The new methodology might help in improving both functions, the researchers say.

In an advance toward glass that remains clear under the harshest of conditions, scientists are report-ing development of a new water-repellant coating that resists both fogging and frosting. Their research

on the coating, which could have uses ranging from automobile wind-shields to camera lenses, appears in the journal ACS Nano.

Michael F. Rubner, Robert E. Cohen and colleagues point out that anti-fogging coatings that absorb water have been the focus of attention lately because of their ability to reduce light scattering and the resultant distortion caused by condensation. However, under extreme fogging conditions, these surfaces may frost and become foggy. They set out to make a better coating to withstand the aggressive conditions.

Their report describes development and testing of a new coating that rapidly absorbs water molecules that cannot freeze in the coating. At the same time, the coating has a water-repelling or hydrophobic effect to larger water droplets. The hydrophobic character means that water droplets do not spread extensively on the coating but essentially remain as flattened droplets.•

TRENDSFor the latest sugar industry news go to: www.internationalsugarjournal.com

A new water-repellant coating for glass


Introduction

Sugar cane trash is an energy resource that is increasing in value and in use. Its use as fuel is increasing worldwide with the move to renewable energy resources. The NSW Sugar Milling Cooperative built electricity cogeneration plants at Condong and

Broadwater (Palmer et al., 2009) with the aim of using sugar cane trash as a supplementary fuel for the plants.

The crop was to be harvested ‘whole crop’ (WC), with both the cane and trash transported to the sugar mill. Harvesting WC results in a significant increase in the total mass of product to be harvested and transported (McGuire et al., 2010). Additionally and

Improving the harvesting and transport of whole crop harvested sugar cane †

NSW Sugar Milling Co-operative Limited, Broadwater, Australia.

* Contact author: Email: [email protected]

M. Inderbitzin and R. Beattie *

abstract

Whole crop (WC) harvesting involves the collection and transportation of the entire sugar cane crop including trash/extraneous matter to the sugar mill. The sugar cane and trash are then separated and the trash used for other revenue streams such as an additional fuel source for cogeneration. Harvesting whole crop results in a significant increase in the total mass of product to be harvested and transported. Additionally and more significantly, it also results in a considerable decrease in the bulk density of the transported material. Strategies to improve the WC harvesting and transportation efficiency have been identified, tested and costed. These strategies included trash particle size reduction (shredding), billet length reduction, vibration, compaction/compression and crop topping. Shredding trash resulted in good increases in transportation bulk density. However, because of harvester extractor cane losses, the cost of this strategy was very high. A modified fan and hood arrangement was tested and reduced the losses. Billeting losses were significant when reducing billet length. Compaction is a promising strategy because there is no cane loss and topping erect crops where possible was a simple way of improving bulk density and trash fuel quality.

Keywords: bulk density, cane loss, harvesting, trash, whole crop

Mejoras en el cosechado y transporte de la cosecha de caña entera

La cosecha de caña entera (WC) comprende la recolección y transporte al ingenio azucarero del total del cultivo de caña, incluyendo desechos y otros materiales. La caña de azúcar y los desechos se separan y estos se utilizan para otras líneas de ingresos, tales como una fuente accesoria de combustible para cogeneración. Recoger la cosecha entera aumenta significativamente la masa total de producto a ser cosechado y transportado. Además, y más significativamente, produce una considerable disminución en la densidad global del material transportado. Se han identificado, probado y costeado las estrategias para aumentar la eficiencia de la recolección y transporte de la caña entera. Estas estrategias incluyen la reducción del tamaño de las partículas del desecho (triturado), la reducción del largo de los trozos, vibración, compactación/compresión y despuntado de la cosecha. El triturado de los desechos resultó en un buen aumento de la densidad global del acarreo. No obstante, debido a las pérdidas de caña a causa del extractor de la cosechadora, el costo de esta estrategia fue muy alto. Se probó un ventilador modificado lo que redujo las pérdidas. Al reducir el largo de los trozos las pérdidas por trozado fueron significativas. La compactación es una estrategia prometedora dado que no hay pérdida de caña y el despuntado de la cosecha en pie, cuando posible, fue una manera simple de mejorar la densidad global y la calidad combustible de los desechos.

Melhora na colheita e transporte da safra de cana-de-açúcar colhida

A colheita integral (WC, do inglês: Whole Crop) envolve a coleta e transporte da safra de cana-de-açúcar na sua totalidade, incluindo resíduos e matérias estranhas para a usina de açúcar. A cana-de-açúcar e o resíduo são separados e o resíduo é usado para outras fontes de receita, tais como fonte de combustão adicional para a cogeração. A colheita integral resulta em um aumento significativo da massa total do produto que precisa ser colhida e transportada. Além disso, ela também resulta em uma diminuição considerável da densidade a granel do material transportado. Estratégias para melhorar a eficiência da colheita integral e o seu transporte foram identificadas, verificadas e estimadas. Estas estratégias incluem a redução das partículas do resíduo (trituração), redução do comprimento do tarugo, vibração, compactação ou compressão e picagem da safra. A trituração do resíduo resultou em um bom aumento da densidade a granel do material transportado. No entanto, devido às perdas da cana nos extratores das ceifeiras, o custo desta estratégia é muito alto. Uma configuração modificada da ventoinha e coifa foi testada e resultou em redução de perdas. As perdas de tarugos foram significativas quando o comprimento do tarugo foi reduzido. A compactação é uma estratégia promissora porque não há perda de cana e a picagem da colheita na posição vertical, quando possível, é uma maneira simples de melhorar a densidade a

granel e a qualidade de combustível a partir dos resíduos.


more significantly, it also results in a considerable decrease in the bulk density of the transported material.

The bulk density of the cane/trash mix has a significant impact on WC harvest and transport costs and so strategies were identified which would increase bulk density. The main strategies identified include:

• shreddingoftrash• billetlengthreduction• compaction• vibration• topping.

These strategies were investigated and costed to identify the most cost effective way of increase WC transportation bulk density.

Shredding trash

Trials were conducted to quantify the impact and feasibility of reducing the trash particle size and its impact on increasing the transportation bulk density of WC harvested sugarcane. A modified primary extractor fan was tested to assess the impact on shredding the trash and then reintroducing it into the harvester elevator to be transported with the cane. Shredding trash using the primary extractor has been demonstrated previously (Spinaze et al., 2002); however, little data on cane losses were collected.

A shredder fan was designed and tested. Key design considerations for the shredder fan were:

• Itshouldbeasimple,robustandlow-costdesign.• Itshouldbeasimplemodificationtoexistingharvesters.• Thenumberof fanbladesshouldbemaximisedtomaximise shredding capability.• Thefanspeedshouldbemaximisedwhilemaintainingcurrent ‘Harvest Best Practice’ (Whiteing, 2002) extractor fan airflow.• Itshould discharge the trash into the elevator

The shredder fan was manufactured and fitted to the existing primary extractor fan mount (Figure 1) and trials were conducted. Improvements to the harvester hydraulics were required because of the high power requirement of shredding trash.

Trials in 2010 resulted in increases in bulk density of between 12% and 22%. Samples were collected during trials for both shredder fan on and fan off treatments to determine the level of extraneous matter. Samples were hand sorted into billets and extraneous matter and weighed. Extraneous matter samples were then mulched and sub sampled and frozen (Figure 2).

These subsamples were used later to determine the level of

Figure 1. Initial shredder fan designs; note machined leading edge both flat (L) and serrated (R)

Figure 2. Sorting, weighing and processing of extraneous matter samples

Table 1. Pol in trash measurements (%) from 2010 shredder fan trials

Trial date Fan off Fan on

20/06/2010 0.6 1.1

7/07/2010 1.1 –

15/07/2010 1.6 –

26/07/2010 1.6 –

17/08/2010 2.8 –

9/08/2010 2.4 4.4

8/09/2010 1.9 –

17/09/2010 2.2 4.0

19/10/2010 1.4 4.2

3&4/11/10 2.7 5.2

5/11/2010 2.2 4.2

Average 1.9 3.8

Improving the harvesting and transport of whole crop harvested sugar cane


pol in the trash (Table 1) (Sichter et al., 2005). The difference between the levels of pol in the trash can be attributed to cane loss through the shredder fan and is thus a measure of sugar lost, as it is unrecoverable.

A financial analysis of the 2010 season results determined that the transportation savings from the increased WC bulk density were less then the value of sugar lost due to the shredder fan.

These results highlighted the need to reduce cane loss in any effort to increase bulk density by shredding trash. A modified prototype hood and fan was designed (Figure 3) and constructed with the aim of reducing cane loss.

The key design considerations for the prototype hood and fan were as follows:

• The fan should be raised higher inthe hood to allow separation of cane and trash in the cleaning chamber with the aim of reducing the amount of cane drawn into the fan and thus reducing cane loss.• Theoverall harvesterheight shouldbe equal to or below the existing harvester height.• The modified and existing hoodsshould be easily interchangeable for trials.• Trash should be shredded anddischarged back into the elevator.• Ifshouldfitwithinexistingharvesterspace constraints.

Key features of the manufactured prototype hood and fan are:

• thefanrunsapproximately500mmhigher than the standard fan in the cleaning chamber• a spiral volute around the outsideof the hood to convey material around and out to where it is discharged at the rear of the hood• a hole in the top of the hood toreduce fan backpressure• 18serratedhardenedsteelblades• anoseconetoimproveaerodynamicperformance• fixedbladestoimproveshredding.

The prototype hood was manufactured and fitted to a harvester for trials during 2011 (Figure 4) Like the shredder trials in 2010, improvements to the primary extractor hydraulics

were required because of the high horsepower requirements of shredding the trash.

Trials conducted with the new prototype hood and shredder fan resulted in an average increase in haulout bulk density (Figure 5) of 14%. Billet length in all trials was kept constant and was on average approximately 180 mm. All trials were conducted in 2-year-old lodged cane. Average extraneous matter levels were 25%. This is typical for lodged 2-year-old cane.

Figure 3. Prototype hood and shredder fan front and top views

Figure 4. Prototype hood and shredder fan fitted to harvester and being tested



Average pol in trash results for 2011 prototype hood and shredder fan trials (Table 2) show a reduction in pol in trash for the fan on treatments in comparison to the 2010 trial results. This is also true when the individual samples are presented as a function of the fan speed (Figure 6).

The reduction in trash pol from 2010 to 2011 shows that, based on limited data, the prototype hood has reduced cane loss. Raising the fan in the cleaning chamber has resulted in a reduction in cane loss. Further trials are required to support these finds. The optimum operating speed for the shredder fan was found to be 1400 r/min

(unloaded – no material flow). Figure 7 shows the approximate fan power for both harvesting and unloaded states for various trials.

The average fan power at 1300 r/min (harvesting) was 58 kW. A speed of 1400 r/min was the optimum for good trash extraction without blocking the outer volute of the fan. Material build up in the volute occurred with maximum fan speed (1600) and with very high levels of material extraction. The level of trash extracted was variable, depending on field conditions and crop. Separate trials showed that at approximately 1300 r/min, the fan separated approximately 60% (by mass) of the extraneous matter.

Billet length

A trial was conducted in 2008 at Broadwater using two similar harvesters in the same field, one with four chopper blades per drum and other with six blades per drum.

Both machines harvested WC and the transportation bulk densities were compared. For this trial an increase in bulk density of approximately 13% was achieved using a six blade per drum chop.

Subsequent bin weight data collected from these two harvesters over an extended WC harvesting period confirmed that the increase in bulk density was approximately 13%.

Based on billeting loss data from the BSES chopper test rig (Hockings et al., 2000), the cost of sugar loss due to the additional billeting losses from the six blades per drum machine was determined as greater than the transportation savings gained from improved bulk density.

Compaction

Compaction was identified as a good strategy to increase WC bulk density. To quantify compaction pressure versus

Figure 5. Average haulout WC bulk density for prototype hood and shredder fan

Figure 6. Measured variation of pol in trash with fan speed for the 2010 and 2011 trials

Figure 7. Prototype hood and shredder fan power requirements

Table 2. Pol in trash (%) for 2011 trials with prototype hood and shredder fanTrial date Fan off Fan on

4/08/2011 1.6 2.0

9/08/2011 1.8 2.2

15/08/2011 1.8 1.9

18/08/2011 1.5 2.7

17/09/2011 2.2 2.0

17/09/2011 2.2 2.4

Average 1.9 2.2

Figure 8. Compaction test rig results showing the effect of shredding/chopping 0%, 50% and 100% of the trash



WC bulk density a small test rig was constructed consisting of a sample drum and hydraulic ram.

Samples were taken and compressed in the rig and hydraulic force recorded. Compaction pressure was then calculated. Tests were repeated for varying samples.

Test rig results (Figure 8) show that compaction pressure on average of greater then 20 kPa would be required to achieve the target bulk density of 250 kg/m3.

Figure 8 also shows the effect of shredding the trash on bulk

density and compaction. Less compaction pressure is required to achieve the target bulk density when the trash particle size is reduced.

Compaction was used extensively during WC harvesting by some harvesting groups to increase road bin weights (Figure 9) and various compaction/levelling machines were developed by groups and trialled. Field data collected from one of these compaction machines support the test rig data (Figure 10).

Other issues associated with compaction of the WC in the multi-lift road bins are the spillage caused by heaping material in the bin prior to compaction and, significantly, the labour cost associated with a dedicated machine for compaction.

This strategy improves the road transport bulk density but does not address the infield haulage bulk density.

Figure 9. Compactor machine working on WC product in multi-lift road bin. Machines used hydraulically operated frames to force material down into the road bins

Figure 10. Compaction data from test rig together with field compaction rig

Figure 11. Oscillating wall test rig (L) and conducting a trial with the test rig (R)



Vibration

The effect of vibration on WC bulk density is commonly observed during transportation. To quantify the effect of additional vibration a small test rig was constructed and WC samples vibrated using small pneumatic vibrators.

Results showed that an increase in bulk density between 9% and 13% was achievable however the use of vibrators on the bin was considered to have less of an effect on bulk density than would be possible if the material in the bin was directly vibrated.

Another small test rig was constructed with a moving partition wall that oscillated (Figure 11) to achieve this.

Trials conducted with this test rig showed an increase in bulk density of 21% when vibrating the material while filling the bin in comparison to no vibration when filling. Additionally, the moving partition had the effect of aligning billets, thus also contributing to the improvement in bulk density.

The test rig demonstrated on a small scale that vibration of WC in the infield haulout while filling the bin was effective, however, in a practical sense, vibration of this kind on a full scale could be difficult and potentially very costly both in capital and maintenance. Scaling up the oscillating wall could also be problematic.

Topping

Topping of one-year-old erect crops is an excellent strategy for improving transportation bulk density. While topping isn’t always

possible it does result in the majority of the wet green leaf and top, which has little fuel value, being left in the field (to leave a trash blanket) and only the dry dead leaf/trash being harvested.

Trials were conducted to evaluate what increase in bulk density could be achieved by selectively removing the top. One-year-old erect cane was harvested WC with and without the topper and results compared.

On average, the WC haulout bulk density was 226 kg/m3. When topping, this increased to 241 kg/m3, an increase of approximately 7% (Figure 12). Average billet length for Trial 1 was 135 mm and 180 mm for Trials 2 to 5.

Topping reduced the average moisture content of trash from 58% to 53%. Extraneous matter decreased from 35% to 28% with topping. On average, topping removed approximately 20% of the extraneous matter (wet weight).

Financial analysis

A financial model was created to assess the relative costs and benefits of various strategies to increase whole of crop harvesting transportation bulk density. The model considers the following bulk density improvement options:

1. Trash shredding – shredder fan and prototype hood2. Compaction of product in multi-lift bin - use of mobile compaction rig

Figure 12. WC topping trials; haulout bulk density

Figure 13. Trash cost from different whole crop harvesting strategies



3. Combination of shredding trash and compaction4. Billet length – use of six blade per drum choppers5. Low primary extractor speed – optimise bin weight with fan speed6. Green cane trash blanket (GCTB) and baling of trash.

In option 6, the trash is transported in bales by truck to the mill, separately from the cane billets. The topping of cane was considered and was modelled separately. The option of vibration was not considered for the financial model.

The key assumptions used to construct the model are listed in Table 3.

The financial analysis in Figure 13 shows a reduction in costs for whole of crop collection (harvesting + transportation to the mill gate), when using trash shredding and/or compaction of product in the multi-lift bin. Strategies where there is no improvement in collection costs are: shorter billets (due to cane loss), low speed fan operation (because of the reduction in tonnes of trash collected), and GCTB and hay baling, (due to the high baling costs and extractor cane loss). The model does not consider the cost of separation of trash at the mill, nor the cost of handling and processing hay bales.

A financial analysis of topping one-year-old crops suggests the dry trash collection costs could be reduced from the WC base case cost of $52 (one-year-old cane) per dry tonne of trash to approximately $45 per dry tonne of trash, despite the reduction in tonnes of dry trash collected.

Conclusions

Harvesting whole crop is problematic and difficult, particularly in large two-year-old lodged crops. Low product bulk density makes harvesting and transportation costly.

Shredding trash is an effective way of increasing transportation bulk density however the impact on cane loss must be considered.

A modified shredder fan and hood was tested and the results

showed that the prototype hood and shredder fan increased transportation bulk density by 14% and that raising the fan is a sensible approach to reducing cane loss.

A significant reduction in cane loss was measured due to the use of a shredder fan and prototype hood in comparison with the shredder fan and standard extractor hood. Cane loss from primary extractors is a significant cost to the sugar industry and further research is required to validate these results.

Compaction is a simple strategy to increase bulk density. There is no cane loss associated with this strategy if spillage from tipping on the pad is avoided.

Topping one-year-old erect crops is a simple and practical strategy to improve bulk density and trash quality. Topping erect cane resulted in an average increase in WC bulk density of 7%, reduced the amount of wet trash collected by approximately 20% and reduced the trash moisture content by approximately 5 percentage points. Topping one-year-old erect cane has also shown to be an effective way of increasing WC bulk density while increasing trash fuel quality.

Acknowledgements

The funding provided by SRDC for this project is gratefully acknowledged. We also thank Chris Norris, Cam Whiteing and Ian Gallard for their knowledge and assistance. The board of Lower Richmond River Harvesting Cooperative for making available their harvester, haul-outs and shed facilities. Growers and harvest crews whose cooperation made this work possible in particular, Craig Rodgers, Graham King and Alf Lock. Thanks to NSW Sugar and BSES Limited staff who assisted with the project.

† This paper was presented at the 2012 Australian Society of Sugar Cane Technologists annual conference and is published here with the agreement of the Society.

References

Hockings, P., Norris, C. and Davis, R. (2000) Chopper systems in cane

harvesters: B: Results of a test program. Proceedings of the Australian

Society of Sugar Cane Technologists 22: 250-255

McGuire, P.J., Inderbitzin, M., Rich, B. and Kent, G.A. (2010) The effect

of whole crop harvesting on crop yield. Proceedings of the Australian

Society of Sugar Cane Technologists 33 (electronic media): 12 pp.

Palmer, C., Farrell, R.M. and Hurt, J. (2009) The development of

cogeneration projects at Condong and Broadwater mills. Proceedings of

the Australian Society of Sugar Cane Technologists 31: 400-409.

Sichter, N.J., Whiteing, C. and Bonaventura, P. (2005) Estimation of

harvester losses by determination of sugar in harvest residue. Proceedings

of the Australian Society of Sugar Cane Technologists 27: 75-82.

Spinaze, D., Harris, H. and Lamb, B. (2002) A harvester-mounted trash

shredder and collection system. Proceedings of the Australian Society of

Sugar Cane Technologists 24 (CD-ROM): 7pp.

Whiteing, C. (2002) Facilitation of harvesting best practice to reduce

extraneous matter and cane loss. SRDC Final Report BSS189, Sugar

Research and Development Corporation, Brisbane.

Table 3. Key assumptions used in the financial model

Average yield 141 t/ha (Broadwater Mill 5-year av)

Average burnt cane pol 11.2 % (Broadwater Mill 5-year av)

Pol lost due to burning 0.5 units

Harvest group crop size 80,000 tonne cane

Trash available additional 24.5% on burnt cane tonnes

Trash moisture content 55%

Diesel price $1.18 /L

Current burnt cane harvest price

$7.50 /t of cane

Current road transportation price

$1.64 /m3

Current WC transportation bulk density

200 kg/m3

Target WC transportation bulk density

250 kg/m3

Sugar price $450/t

Electricity income $70/MWh



Comparison of a DCJ factory with a typical diffuser factory

Before commenting on the literature surveyed, it is helpful to look at the difference between the front ends of a conventional factory and a proposed DCJ factory, as illustrated in Figures 1 and 2. Typical temperatures of juice in various locations have been included.

Lime and flocculant could be added to the front of the diffuser (Figure 2), and the juice directed through the cane bed in order to filter out the resulting mud particles. In doing this, at least one stage in the diffuser would be ‘sacrificed’. For example, a 12 stage diffuser would be reduced to 11 stages, but the first stage would double in size.

From Figures 1 and 2 it can be seen that there is significantly less equipment in the proposed DCJ factory than the typical factory. Under DCJ configuration, the following would no longer be required:

• Mixedjuice(MJ)tank• Flashtank• Clarifier• Mudpumpsandscales• Someheatingcapacity.

In a new factory, the front end structure could also be significantly smaller due to the large footprint and height of most clarifiers.

Direct clear juice: A feasibility study and piloting investigation into the production of clear juice in a sugarcane diffuser

Sugar Milling Research Institute NPC, University of KwaZulu-Natal, Durban 4041, South Africa.

Email: [email protected]

P.S. Jensen

abstract

Since the establishment of mud recycling to the diffuser in 1998, the shredded cane bed has proved itself as an efficient filter of mud solids in most South African diffuser factories. This has raised the question of whether, under the right circumstances, these solids could be filtered directly in the diffuser, thus bypassing the need for settling clarification. A pilot diffuser-clarifier was configured at the Sugar Milling Research Institute NPC (SMRI) to investigate the quality of juice that could be obtained, and the conditions required for Direct Clear Juice (DCJ) production. This paper looks at previous attempts at DCJ production, the potential benefits of replacing settling clarification with DCJ production and some results of piloting work performed at the SMRI.

Keywords: clarification, clear juice, diffusion, mud recycling

Jugo claro directo: Un estudio de factibilidad y una investigación piloto sobre la producción de jugo claro en un difusor de caña de azúcar

Desde que se estableció el reciclado de lodos al difusor en 1998, el lecho de caña triturada ha mostrado ser por sí misma un filtro eficiente para los

sólidos del lodo en la mayoría de los difusores de las fábricas de Sudáfrica. Esto ha suscitado la pregunta de si, bajo condiciones adecuadas, estos

sólidos podrían ser filtrados directamente al difusor, evitando la necesidad de una clarificación por decantación. En el Instituto de Investigaciones

para la Molienda de Azúcar NPC (SMRI) se configuró un difusor-clarificador para estudiar la calidad del jugo que podía obtenerse y las condiciones

requeridas para la producción de Jugo Claro Directo (DCJ). Este trabajo examina tentativas previas de producción de DCJ, los beneficios

potenciales de reemplazar la clarificación por decantación con producción de DCJ y algunos resultados del trabajo piloto efectuado en el SMRI.

Caldo claro direto: Um estudo de viabilidade e condução de investigação na produção de caldo claro em um difusor de cana-de-açúcar

Desde o estabelecimento da reciclagem do lodo para o difusor em 1998, o leito da cana triturada já provou ser um filtro eficiente de sólidos do lodo

em fábricas de difusores na África do Sul. Com isso, levantou-se a hipótese de que em certas circunstâncias esses sólidos poderiam ser filtrados

diretamente no difusor, com isso evitando a necessidade de clarificação por sedimentação. Um clarificador-difusor piloto foi configurado no Sugar

Miling Research Institute NPC (SMRI) para investigar a qualidade do caldo que poderia ser obtido, e as condições necessárias para a produção de

Caldo Clarificado Direto (DCJ, do inglês: Direct Clear Juice). Este artigo analisa as tentativas anteriores de produção de DCJ, os prováveis benefícios

da substituição da clarificação por sedimentação pela produção DCJ e alguns resultados do trabalho piloto conduzido no SMRI.


The clear juice leaving the diffuser in Figure 2 is at a higher temperature than the draft juice leaving the diffuser in Figure 1. This implies that a DCJ diffuser requires greater scalding juice heater capacity than a conventional diffuser. The juice would be suspended solids ‘free’, and be conducive to heating in plate heat exchangers, or possibly fed directly into the evaporator train if there was sufficient capacity to both heat and evaporate the juice in the first effect evaporators (Peacock and Love, 2003).

Introduction and history

The earliest discovered reference to the idea of performing clarification within a cane diffuser is Payne (1965). He recorded that “considerable interest was raised” when operating their pilot plant diffuser at the possibilities of clarification within the diffuser. Dry lime was pumped onto the cane between the buster and fiberiser to promote mixing of lime and cane external to the diffuser. Laboratory heating of the treated mixed juice resulted in no secondary precipitate.

After five years of operating cane diffusers, Payne (1968) noted that clarification within the diffuser was best achieved by:

• Addinglimeslurrytothecaneenteringthediffusionvessel;• Passingtherecycledjuicethroughthescaldingjuiceheaters;• Filtering the resulting flocout of the juiceby a secondpass through the cane bed.

He also commented that:

• The fibre increased the effectiveness of flocculation and the time and temperature necessary were substantially less than in usual clarification processes;

• Higher liming levelsproduced juicesof lower turbidity;• Clarified juice from this treatment averaged lower turbidity than conventional clear juice from milling;• Conditions affecting the quality of clarification were pH, temperature, dilution, recycle, and cane quality including trash content;• HigherpHlevelsacceleratecolourform- mation, especially with a significant pro-

portion of leafy material. Pioneer mill in Hawaii averaged 10% trash during the trials.

In hindsight, one might expect the colour increase reported to be largely a result of the lime slurry being added directly to the shredded cane.

Chen (1972) recorded results from trials performed in 1969 where diffuser clarified juice was compared with milling-defecation juice. He noted that:

• Juicecouldbeclarifiedat70-80°CandatapHof7.0-7.2;• Nosecondaryprecipitationwasfoundindiffuserclarifiedjuice, i.e. clarification was complete;• Diffuserclarifiedjuicecontained,almostwithoutexception,less turbidity than clarified juice by conventional milling defecation.

Lamusse (1981) carried out tests on liming in a De Smet cane diffuser in Venezuela. He found it possible to obtain a juice requiring no further clarification by liming to a pH of 7.0 to 7.3 in the first stage of the diffuser. There was, however, heavy precipitation from the juice in the first vessel of the evaporator. The diffuser, in these experiments, was operated below 70°C, which would not have been enough to precipitate all the protein in the juice.

Lamusse remarked that, “The absence of recent references on clarification in diffusers seems to indicate that the process is no longer favoured.”

In addition to his comments on the Venezuela trial (Lamusse, 1980), the following was discovered through personal communication 1:

• Thetrialwasperformedduringthecommissioningofthefirst diffuser installed in South America;

Figure 1. Front end configuration of a typical diffuser factory with mud recycle

Figure 2. Proposed front end configuration of a DCJ factory



• Lime was dosed into the front stage of the diffuser under normal configuration;• TherewasnopHmeasurementorcontrolofthejuice;• Noflocculantwasdosedintothediffuser.• Thetrialwasstoppedafterashortwhileduetosevereflooding in the front of the diffuser.

It was also discovered (Lamusse, 1981) that there were no lifting screws installed in the diffuser at the time of the trial. The conditions and results of the three previous trials mentioned above are summarised in Table 1.

Although not a direct reference to DCJ, Meadows et al. (1998) showed the effectiveness of the diffuser bed at filtering suspended solids from clarifier muds, with no adverse effects on extraction, or evidence of increased sucrose destruction in the diffuser. Since then, mud recycling has been adopted as the preferred method of treating clarifier mud in South African diffuser factories.

Lionnet (2000) observed that based on the low suspended solids of diffuser juice, the proven ability of the diffuser at filtering clarifier muds, and the proven practice of using saccharate to facilitate liming in the diffuser, it should be possible to produce a treated diffuser juice which would be suitable as a feed for plants based on the new separation technologies.

Since the Lamusse trials, Ivin et al. (1987) and Schäffler (1988) showed that liming in a diffuser can lead to increased acetic acid concentrations in mixed juice. This leads to various downstream complications. They both commented, however, that where liming was well controlled, the increase in acetic acid would be lessened. Schäffler compared four factories which were liming in their diffusers, and found only one (Felixton) to have an increased concentration of acetic acid due to lime addition in the diffuser. It is also worth noting that at Felixton the lime was added at 8 points, compared with one or two points in the other three factories.

Reasons for previous non-implementation

Almost 50 years after the DCJ idea was first proposed, there are still no known installations in operation. Upon examination

of the literature referencing the idea, all three authors were positive about the concept, and there are no clear reasons for its non-implementation. The reasons may be one or a combination of the following suppositions:

1. The step change from milling to diffusion was large enough in itself, and the industry was not ready for two steps in one;2. The operational benefits of DCJ were not enough to justify its implementation;3. Concern over increased sand being sent to the boilers;4. Concern over decreased extr-action due to loss of stages in the diffuser;

5. Concern over decreased percolation in the diffuser;6. Concern over poorer juice quality.

If DCJ is to be adopted by the industry, the above six concerns need to be addressed, and be shown to be less costly to a mill than the benefits of DCJ.

Reasons for reconsidering DCJ

1. The step change from milling to diffusion was large enough in itself, and the industry was not ready for two steps in one

The step from milling to diffusion has now been widely adopted by the sugarcane industry. The advantages of diffusion have been dealt with in detail by Rein (1995). The cane diffuser has proved itself to be easy to operate, robust and, since the onset of mud recycling in 1997 (Meadows et al., 1998), an effective filter of clarification mud solids. The step from conventional clarification to DCJ is now significantly less than it was in 1968.

2. The operational benefits to DCJ were not enough to justify its implementation

This raises the question: “What would be the benefit to a mill today if DCJ could be successfully implemented?” A 300 tcph factory was modelled using the computer program Sugars™, and the basis for the calculations can be found in Appendix 1. The benefits are summarised in Table 2. The advantages of a DCJ factory would include:

2.1 Reduced heat losses

In the typical configuration, juice exits the diffuser at 65°C. Due to the fact that settling clarification requires the juice to be ‘air free’, it needs to be heated to above its flash temperature. The vapour is flashed to the atmosphere. Under DCJ, flashing is not required, and this evaporation would instead take place in the multiple effect evaporator train. The energy in the flashed vapour would

Table 1. Summary of results of previous direct cane juice (DCJ) trials compared with conventional clarification

Author Positives Negatives Conditions/observations

Payne (1968) Lower turbidity Higher colour Lime slurry added to shredded cane. Trash in cane 10%. 1 stage co-current. pH ~7. No flocculant addition mentioned. No lifting screws

Chen (1972) Lower turbidity. Lower colour

Temp 70-80°C. pH 7.0-7.2. No flocculant addition mentioned. No lifting screws

Lamusse (1980) Adequate turbidity Precipitation in first evaporator. Flooding in diffuser

Lime added to first stage. Temp below 70°C. No flocculant addition mentioned. No lifting screws

Direct clear juice: A feasibility study and piloting investigation into the production of clear juice

in a sugarcane diffuser


then be mostly recovered in the evaporator train rather than being lost to the atmosphere.

After lime and flocculant addition, the juice flows by gravity into the clarifiers. Depending on the type and number of clarifiers in operation, the residence time is usually between 30 min and 2 h. A significant amount of heat is lost through the walls of the clarifier during this time, such that by the time it enters the CJ heaters it is at approximately 98°C (Jensen, 2001). According to Wright (2006), mud temperatures as low as 93°C are not uncommon.

2.2 Reduced inversion losses

A significant amount of sucrose is inverted while the juice is in the clarifier. This is mainly due to the high temperature of the juice and the long residence time. Vukov’s model (Vukov, 1965) was used to predict the amount of sucrose which is inverted in the clarifier under the conditions specified in Appendix 1.

2.3 Removal of mud

Under DCJ configuration, all equipment usually associated with the handling of mud would be eliminated. Mud would no longer be a sugar factory stream. The benefits would be reduced sampling and analytical load, removal of mud scales, improved hygiene and reduced sucrose losses.

2.4 Improved juice quality

During the previous DCJ trials, Payne (1968), Chen (1972) and Lamusse (1980) all noted lower turbidity juice than CJ from conventional clarification. Trials performed at the SMRI and reported on here also suggest that this was likely. Settling clarification is susceptible to mud carryover if conditions in the clarifier are disturbed (Mkhize, 2003). The negative consequences of mud carryover include increased evaporator fouling, increased sugar colour, and expected reduced sugar filterability (Sahadeo et al., 1998). DCJ would be of particular advantage where downstream operations consisted of new technologies such as membrane filtration or resin-based separations. Mud carryover in clear juice was a challenge often encountered by the White Sugar Milling (WSM) (Jensen and Kitching, 2007) slipstream plant (personal communication ).

2.5 Reduced heating area required and option for cheaper heaters

Less heating area is required in a DCJ factory than a conventional factory. In a conventional factory, it is essential to heat the juice to above its flash temperature in order to expel the air from the juice before settling clarification. A DCJ factory, by comparison, does not need the heating area required to heat the juice from 98 to ~104°C. A slightly higher load is, however, placed on the evaporators. Furthermore, all heating in a DCJ factory, except the

first pass through the scalding juice heaters, is performed on ‘clear juice’. Fouling is expected to be reduced as a result. Plate heaters, which have a Heat Transfer Coefficient (HTC) of two to three times that of tubular heaters (Rein, 2007) are worth considering, if the juice to be heated is low in suspended solids.

2.6 Improved energy efficiency by using low grade steam for final stage heating

The vapour to the final stage heating before a clarifier is usually required to be vapour bleed from the first effect evaporator (V1), in order to heat the juice to above its flash temperature. Under DCJ this is no longer a requirement, and second effect vapour bleed (V2) could be used instead. If the final juice heaters raise the temperature from 89 to 98°C and V2 is used instead of V1, a significant steam saving can be achieved, as is described in Appendix 1 and Table 2.

3. Concern over increased sand being sent to the boilers

Sand in bagasse is undesirable as it lowers the calorific value of the bagasse slightly, and may lead to increased wear in the boilers. Meadows et al. (1998) claimed that the increase in ash % bagasse when moving from mud filtration to mud recycling is less than 10%. The success of mud recycling in South Africa suggests that the benefits gained outweigh the negative effect it has on the boiler. Under DCJ the extra ash load on the bagasse is equivalent to the ash load on bagasse under mud recycling. For mills still operating mud filters, the transition to DCJ would contain all the benefits associated with mud recycling (Jensen, 2001), as well as those associated with DCJ.

4. Concern over decreased extraction due to loss of stages in the diffuser

Under DCJ configuration, a diffuser could ‘lose’ between one and three extraction stages. To determine the loss of extraction which might be associated with this combining of stages, a simplified diffuser mathematical model was constructed. By adjusting the stage efficiency parameter for each stage in the model, the brix curve could be fitted to that of a typical profile obtained from a diffuser with mud recycling (Figure 3).

Table 2. Summary of benefits to a 300 tons cane/hour direct clear juice (DCJ) factory over a conventional factory

Description of operation Annual savings

2.1 Elimination of vapour flashing R703,248

2.1 Elimination of clarifier heat losses R602,784

2.2 Elimination of clarifier inversion losses R1,307,411

2.3 Removal of mud ?

2.4 Improved juice quality ?

2.5 Reduced heating area required and option for cheaper heaters ?

2.6 Use of V2 instead of V1 in final juice heaters R659,568

R3,273,011+?



The stage efficiencies (defined as the percentage of brix entering a stage that exits in the underflow into the tray below) required to fit the model to the Brix curve were higher in the front of the diffuser. This is to be expected, as percolation rate is highest in the front of the diffuser. From the model, a brix extraction of 98.7% was calculated. Stages were then sequentially removed from the model to estimate the effect this would have on extraction. The results are shown in Figure 4. It can be seen that removing three stages in the model results in a predicted loss of extraction of less than 0.5%. The monetary (Rand) value of the loss in extraction was also calculated, and is shown in Figure 4.

In practice, the loss in extraction due to the combining of stages is expected to be even less than the numbers shown in Figure 4, as the overall length of the diffuser, and hence cane residence time, is still the same. The fact that a stage is double the length should mean the extraction efficiency of the stage is increased, thus offsetting somewhat the negative effect

of reducing the number of stages. Rein (2007) alluded to the fact that the choice of 12 stages in a diffuser is also influenced by structural constraints and not extraction theory alone.

It is also worth noting the ‘kink’ in the typical diffuser brix curve in Figure 3 as a result of mud recycling to the diffuser. This is clearly not ideal from an extraction point of view, but has been shown to have minimal impact on extraction (Meadows et al., 1998). Under DCJ the mud is essentially recycled to the front of the diffuser which, from a brix point of view, is the best location.

In light of these observations, it is expected that the negative impact on extraction, through ‘losing’ up to three stages in a 12 stage diffuser, should be less than the benefits of a DCJ configuration described in Table 2.

5. Concern over decreased percolation in the diffuser

Although there is no mention of flooding in any of the previous DCJ investigations found in the literature, personal communication1 revealed that a trial was stopped due to flooding in the diffuser. Love and Rein (1980) and Lionnet (2000) all found percolation rate to decrease with an increase in pH. After conducting DCJ piloting at the SMRI it is suspected that the decreased percolation rate reported by these authors was more a result of calcium precipitation than a reduced concentration of hydrogen ions. No tests were performed with bases other than lime to test this speculation.

The diffuser used by Lamusse (1980), and the columns used by Love and Rein (1980) and Lionnet (2000), contained no lifting screws. The trials performed by Payne (1968) were on a Silver Ring diffuser which also did not contain lifting screws. Lifting screws are critical to the implementation of

mud recycling to the diffuser, and are therefore also expected to be a requirement in a DCJ diffuser. One of the reasons for relooking at DCJ is the success of lifting screws in diffusers since they were first tested by Huletts Sugar Ltd at Empangeni in 1968 (Van Der Riet and Renton, 1971).

DCJ piloting at SMRI in 2011

1. Piloting objectives

The four objectives of DCJ piloting at the SMRI in 2011 were:

1. To determine whether DCJ of similar quality to mill CJ could be made.2. To assess the filtration time required for DCJ production.3. To assess the effect on percolation rate of DCJ production.4. To observe factors which possibly affect DCJ production and should be further investigated.

Figure 4. Mathematically modelled extraction as a function of number of stages

Figure 3. Diffuser model fitted to typical diffuser (with mud recycle) brix curve




2. Equipment

A schematic view of the rig is shown in Figure 5, and major equipment is described.

Heated tank - A 200 litre tank equipped with:• Steamheatingcoil.• Thermocoupleusedtocontrolthetanktemperature.• pHprobeformonitoringthepHofthejuice.• Stirrerandstirrerbaffles.• Overflow valve formaintaining a level in the tank above the stirrer and heating element.

Diffusion column - A 300 mm diameter by 1.3 m high glass column featuring:

• A Perspex distribution plate to ensure even distribution of the juice into the column.• A tank below placed on a weighing scale for measurement of percolation rates.

Turbidity meter (TM) - An inline absorbance meter developed by the SMRI and marketed by Sugarequip (Pty) Ltd. The unit, as described by Mkhize (2003), was used to measure the absorbance of mill CJ, as well as for continuous monitoring of DCJ absorbance during each run.

Bubble tank (BT) - A 1 litre tank which allows air bubbles to be released from the juice before it flows by gravity through the turbidity meter. Temperature and pH of the juice was logged in the tank.

3. General procedure

Each of the runs performed followed the general procedure detailed below:

• 110kg juice,25kgshreddedcane,milkof lime and blended flocculant were collected from a mill on the day of each run.• The juicewasaddedto thetank,andthestirrer was started.• Thecanewasdroppedintothediffusioncolumn.• Thejuicewasheatedinthetankto95°C.• Lime was added until the desired pH setpoint was reached.• Flocculant was usually added directly after the pH setpoint was reached.• The overflow valve was opened to allow juice from the tank to flow into the diffusion column.• Flocculantwascontinuouslydosedintothejuice at the outlet of the tank, before it entered the column.• The juiceexiting thecolumnwaspumpedback into the heated tank, where the temperature of the recirculating juice was maintained at a maximum of 80°C (higher temperatures could not be reached due to heat losses and an inadequate heating coil).

• Lime was continuously added to the tank during the run to maintain a chosen pH.• Asidestreamofjuiceexitingthecolumnwaspassedthrough a turbidity meter to monitor the clarity of juice over time.• TemperatureandpHwerealsologgedduringeachrun.• The run was stopped after about 40 minutes, or when the turbidity had stabilised.

At intermittent times, the flow rate of juice through the column was measured (by shutting valve V2 after the pump for a few seconds, and observing the increase in mass measured by the scale), allowing percolation rate to be calculated in m3 juice per m2 of cross-sectional area per minute. A printout and commentary of one full run is given in Appendix 2.

4. Design of experiment

The initial goal of piloting was to check the possibility of producing DCJ of similar quality to mill clear juice. This goal was achieved after run 1! It was clear that simply filtering treated juice through the cane bed for long enough could reduce its turbidity to below that of mill CJ. The focus then became to ‘tweak’ the procedure to produce DCJ of similar quality to mill CJ in as short a time as possible, while maintaining high percolation rates.

A multitude of choices are available when deciding on an experimental procedure of this nature. Some of these choices are

Figure 5. Graphical representation of the Sugar Milling Research Institute direct cane juice (DCJ) pilotting rig stages



shown in Table 3 below. The highlighted cells represent the ‘base levels, which were chosen based on the experience gained in the preceding runs.

Table 4 shows the difference in operating conditions between the runs.

5. Results

5.1 Mill CJ absorbance

Upon collecting cane on the morning of each piloting run, a sample of mill CJ was also collected from the mill. The sample was passed through the TM in order to determine its absorbance. Its turbidity was also tested by the ICUMSA method (Anon, 1985) using a wavelength of 420 nm. The results (Table 5) were used as the basis on which to assess the quality of DCJ produced during piloting. A large range, in the turbidity of CJ collected from the mill, was observed.

It was decided to compare the DCJ absorbances for each of the runs to the average of the mill CJ absorbances for three reasons:

1. It allowed a comparison between individual DCJ runs with generally encountered mill CJ turbidities.2. The mill CJ samples did not originate from the same cane consignment as the cane and juice used in the DCJ trial, and thus a direct comparison is misleading.3. The DCJ absorbance trends tended to be more uniform than the mill CJ results. Mill CJ quality is largely influenced by the conditions in the clarifier at the time of sampling, and averaging the results gives a better indication of the quality of typical mill CJ.

5.2 Filtration time

As the limed and flocculated juice percolates through the shredded cane bed, mud particles are trapped between the fibres. At the same time, new impurities are washed out of the ‘fresh’ cane in the column. Most of these impurities are too small to be trapped by the cane fibres, and they exit the column with the percolating liquid. Continuous monitoring of the turbidity at the exit of the column shows it to decrease with time. This decrease is a result of three factors working together:

1. The amount of impurities left in the cane decreases with time.2. Bed compaction and a mud layer in the bed results in a tighter filter with time.3. The clarity of the feed to the column improves with time as the juice exiting the column is recycled through it.

Table 3. Factors and levels available in the design of the direct clear juice (DCJ) piloting experiments

FactorChoices/levels

A B C D

1. Starting juice Water Scalding juice Clear juice Mixed juice

2. pH juice initially limed to: No lime (±5) 5-6.8 6.8-7.4 7.4-7.6

3. Type of base used Milk of lime Saccharate Other

4. Initial floc added (ppm) No initial floc <1.5 1.5-5 >5

5. Total floc added within 15 minutes (ppm)

No floc <1.5 1.5-5 >5

6. Percolating temperature (°C) <70 70-85 >85

7. Mud from initial clarification All mud filtered through cane

5 L removed from system Mud mixed with cane when loading column

8. Bed manipulation (lifting screw) No manipulation Manipulation within 15 minutes Manipulation after 15 minutes

Table 4. Levels chosen for each of the piloting runs (blank cells indicate base values)

Run

Factor Base 22/6 19/7 02/8 04/8 23/8a 23/8b 14/9 20/9 23/9 30/9 5/10 25/10

1 B C A

BA

SE

BA

SE

D D D

2 D C C C A A B C C C

3 A B

4 C A A

5 C D D

6 B A

7 B A A A

8 C A A A A A A B B

Table 5. Online absorbance and turbidity measurements from mill clear juice (CJ) samples

Online absorbance ICUMSA turbidity

No. of samples 13* 14

Average 1.15 8960

Max 2.70 16093

Min 0.25 2523

Standard deviation (σ) 0.71 4108* Online absorbance was not measured for one of the samples




The turbidity reduction over the first 20 minutes of the two base runs is shown in Figure 6, where the average of the mill CJ absorbances and the average plus or minus one standard deviation are plotted as horizontal lines. It can be seen from Figure 6 that after ±9 minutes of filtration, the DCJ turbidity was similar to the average mill CJ turbidity.

5.3 Percolation, and the effect of bed agitation (lifting screw)

Lionnet (2005) showed lab percolation rates to be largely dependent on cane packing density. For a density of 450 kg/m3 he found the percolation rate to be ~0.3 m3/m2/min. The column used for his experiments was 450 mm in diameter and the packed cane bed heights were ~0.45 m deep.

Love and Rein (1980) recorded lab percolation rates of ~0.23 m3/m2/min with a cane packing density ~450 kg/m3. The column used for their experiments was 320 mm in diameter and the packed cane bed heights were ~1.5 m deep.

The SMRI DCJ piloting rig used a 300 mm diameter column, with bed heights between 0.6 and 0.8 m. The plot of percolation rates with time for the base level runs are shown in Figure 7. The rates were initially different due to a difference in the rate of opening the outlet valve from the tank, but were thereafter similar to each other, and to percolation rates recorded by previous authors.

It can be seen that the percolation rate tends to decrease exponentially with time, in a similar way to the turbidity curves in Figure 6. Although the percolation rates of the above two runs appear normal, with time, percolation rates as low as 0.05 m3/m2/min were observed. For this reason it was decided to insert the equivalent of a diffuser lifting screw (see Figure 8) into the column before adding the shredded cane.

After a certain time, the ‘screw’ was removed from the column in such a way as to redistribute the mud within the cane. Agitating the bed had a significant effect on percolation rate. The rate would immediately increase, but also remain at a much higher value than the stabilised percolation rate before agitation.

In Figure 9, the time at which the bed was agitated is indicated by the vertical section of the percolation curve (inserted manually into the data for clarity). The only run in which the percolation rate decreased again to low levels was the run on 05/10. During this run the bed was agitated after just 6 minutes. This indicates that a significant portion of the mud had still not been filtered by the bed and was thus still present to form a layer in the cane after agitation. A second agitation was performed on this run after 38 minutes, and the percolation rate increased and thereafter stabilised. In light of these results, the lifting screws in a full scale DCJ diffuser should not be located too close to the front. Percolation problems seem to be the main reason for discontinuing DCJ trials in the past (personal communication 1). The fact that lifting screws are now standard features in most diffusers is a reason to relook at

Figure 8. The ‘lifting screw’ used for bed agitation

Figure 6. Effect of filtration time on turbidity for the two base runs

Figure 7. Trend of percolation rates with time for the two base runs

* Cane packing density was not measured for run 14/09



the idea on a full scale, as bed agitation significantly increases percolation rate. The design of the lifting screws should be examined more closely, as it is desirable to distribute the mud solids within the bed while still minimising the passage of fines completely through the bed during agitation.

5.4 The choice and effect of type of juice used during each run

One of the differences between the DCJ piloting rig and a full scale diffuser is the ratio between liquid and fibre in the plant. The

SMRI DCJ column contained approximately 25 kg cane. At an imbibition % fibre of 350%, this equates to 11 kg of imbibition which should be added to the cane in order to replicate a typical full scale diffuser. Due to the requirement of a liquid holdup in the column and the tanks associated with the rig, 110 kg of juice was required to be in circulation during each run. This raised the question of the best choice of juice with which to start each run. On a full scale, each kilogram of cane is required to filter out only the suspended matter originating from itself. In the pilot plant, a far higher solids load could be imposed upon the cane than would be encountered on a full scale. The base choice was to start with scalding juice, and to remove ~5 L of mud after the initial clarification in the heated tank in order to reduce the filtration load on the cane in the column. CJ and MJ were also tried as starting materials, and the results are shown in Figure 10.

The CJ run showed the most rapid decrease in turbidity of all the runs. Within three minutes the turbidity originating from the cane in the column could be reduced to below the average mill CJ absorbance. Using MJ as the starting material resulted in a turbidity reduction very similar to the base runs.

The percolation rate in the CJ run was extremely low. This result was surprising, as the lower filtration

load was expected to result in higher percolation rates. The packing density of this run was high, as blinding of the bed tends to result in it becoming more compacted. The percolation rate for the MJ run was also low, and the reasons for this are unclear.

5.5 The effect of initial juice pH

The two base level runs were limed to ~7.5 pH before filtration through the bed began. The only difference between these runs and run 20/09 was the initial pH. The lime addition and juice pH for the three runs are shown in Table 6.

Figure 10. Turbidity and percolation results for three different starting juices: 30/09 mixed juice, 04/08 clear juice, 14/09 and 23/09 scalding juice


Figure 9. Trend of percolation rates after bed agitation

Table 6. Lime addition and initial pH of four piloting runs

RunInitial clarification 10 minutes into run

pH MOL added (kg) pH MOL added (kg)

14/09 (base) 7.5 0.5 6.3 0

23/09 (base) 7.6 0.5 6.9 0

20/09 6.5 0.2 6.5 0.2

MOL = milk of lime




The turbidity and percolation trends are shown in Figure 11. The starting pH appears to have little effect on the rate of turbidity removal. It is not clear why the base run percolation rates were significantly higher than run 20/09 which was initially limed to a lower pH. It is highly unlikely that it is due to the lower initial pH, especially as previous authors (Love and Rein, 1980) report higher pH as contributing to lower percolation rates.

5.6 Individual effect of heating, lime addition and flocculant addition

The juice was heated to 95°C before being circulated through the cane bed. It can be seen from Figure 12 that even without lime or flocculant addition, the juice turbidity was brought to below the average mill CJ value within 40 minutes of filtering. The percolation rate, even after 40 minutes, was above 0.4 m3/m2/min, which was significantly higher than the runs where lime and flocculant were added. To test the effect of gradual lime addition to the juice, it was dosed in five batches of 100 mL. The pH increased by about half a unit, and percolation rate continued to decrease. There was little evidence of a turbidity reduction as a result of lime addition in this way. Percolation rate continued to decrease throughout the test. Flocculant (1 ppm) was dosed after 81 minutes, and a step reduction of 20% in absorbance was seen shortly afterwards.

A similar test was performed using water instead of scalding juice as the starting material, and the results are shown in Figure 13. Once again it is evident that there is a significant turbidity reduction with just heating and filtration of juice through the cane, without a large percolation reduction. The addition of lime both decreased percolation rate and turbidity. The addition of floc further decreased the percolation rate. The absorbance reading was already off the scale before floc was added.

Figure 11. Turbidity and percolation trends investigating the effect of initial pH on direct cane juice (DCJ) production


Figure 12. Turbidity and percolation (run 24/08b) with heating only, then lime addition, then flocculant addition. Starting material was scalding juice

Figure 13. Turbidity, percolation and pH (run 24/08a) with heating only, then lime addition, then flocculant addition. Starting material was water



The above results suggest that it may be possible to produce DCJ using no, or minimal lime. The juice pH could be adjusted after the diffuser using calcium-free bases such as sodium bicarbonate or carbonate (Lionnet, 2000). This would be of particular benefit where ion exclusion chromatography, which relies on a low calcium feed, was being considered as a downstream process.

5.7 Optimal temperature for DCJ production

Lamusse (1980) suggested that operating temperatures below 70°C would not be enough to precipitate all the protein in the juice. Heating the juice above 85°C in a diffuser is generally not recommended due to increased colour formation, inversion losses and heat losses. The turbidity curve for run 22/06 in Figure 14 suggests that insufficient heating increases the time required to reduce the turbidity of DCJ. Operating temperatures between 75 and 80°C are adequate. Higher temperatures were not tested. The scalding juice temperature is, however, required to be high in order to heat the cane quickly from ~25°C to the operating temperature.

Figure 15 shows the percolation of run 22/06 to begin lower than the base curves, but to approach the same value after 20 minutes

5.8 Colour change during DCJ production

A colour comparison is only possible for the runs using MJ as the starting material, as the ratio of scalding juice (which is high in colour) to cane is far more in the pilot plant than in a full scale diffuser. During each of the MJ piloting runs, samples were taken at different times for laboratory analysis. The ICUMSA colour of the samples was measured, and the results are shown in Figure 16.

The results in Figure 16 showed the mill MJ colours and CJ colours to be quite different. This is

Figure 14. Turbidity and temperature curves suggesting an effect of temperature on turbidity removal

Figure 15. Percolation rate curves comparing run 22/06 (lower temperature) to the base level runs

Figure 16. Colour change during direct clear juice (DCJ) production





likely due to the catch sampling employed and the fact that the mill CJ and MJ samples probably did not originate from the same batch of cane. In run 25/10, for example, the CJ colour is higher than the MJ colour, while the reverse was measured for the other two runs. It is, however, useful to note that the DCJ colour did not appear to increase with filtration time.

5.9 Effect of type of lime

Run 19/07 was conducted using saccharate, whereas all other runs used MOL. The results of run 19/07 are shown in Figure 17, along with the base level results. There is no discernable difference between the use of saccharate and MOL.

5.10 Visual comparison of DCJ and mill CJ

As part of the DCJ research project at the SMRI, a new analytical method was developed as a quick visual comparison of the suspended solids between juice samples (Jensen, 2011).

Two samples of DCJ (collected after ~13 minutes) were

centrifuged simultaneously in small centrifuge tubes in order to compare the settled suspended solids in the juice with a sample of centrifuged mill CJ. The DCJ samples shown in Figure 18 contained noticeably less settled matter than the CJ sample. The white markers on the centrifuge tubes indicated the level of the settled solids after centrifugation.

Conclusions

It was observed that DCJ of better quality than mill CJ could consistently be produced on a piloting scale. The filtration time required for DCJ to reach average mill CJ quality was ~9 minutes. There was a definite reduction in percolation rates during DCJ production. The percolation rate could however be increased back to normal levels after agitation of the bed with a ‘lifting screw’. Furthermore, the following were tentatively observed during DCJ piloting:

• No observable difference between using saccharate or milk of lime.

Figure 17. Turbidity and percolation results using saccharate (run 19/07)


Figure 18. Centrifuged juice from run 30/09/2011(left) and 25/10/2011 (right)

CJ = clear juice DCJ = direct clear juice MJ = mixed juice



• Thebedhascapacitytofilteroutmoresolidsthanjustthose originating from the bed itself.• A minimum percolating temperature of 75°C is required for quick reduction in DCJ turbidity.• Noincreasein juice colour with filtration time.

Based on historical results, developments in diffuser technology over the last 50 years, and results from piloting at the SMRI in 2011, it appears that the replacement of conventional clarification with DCJ production is worth looking at on a full scale once again.

Recommendations

It is recommended that further aspects of DCJ production be investigated to get a better understanding of the process. The investigations should include more detailed studies on:

• TheformationofaceticacidduringDCJproduction.• Acomparisonbetweenmilkoflimeandlimesaccharate.• AcomparisonincolourbetweenDCJandmillCJ.• AcomparisonbetweenthefoulingcharacteristicsofDCJand conventional CJ.• pHcorrectionwithalternativebasesafterthediffuser.• OptimaltemperatureforDCJproduction.• Designofliftingscrews.• Possibleimpact on cane payment.

Furthermore, DCJ production could open the door to advancements in a cane sugar factory which were previously unattractive or not considered. These include:

• Colourremoval(orother)additiveswhichcouldbefilteredout in the diffuser.• Arelookatenergyefficiencyduetoareconfiguredfrontend.• New technologieswhichwere previously unattractive due to the variability of juice quality from conventional clarification.• Newdiffuserdesigns.• DeepbedfiltrationofDCJ.

Acknowledgements

The author is grateful for the help received in preparing this paper, and would like to acknowledge inputs from Ramesh Ramsumer, Seppy Ramsuraj and Rendani Ramaru who assisted during with piloting; Dr Dave Love for his advice with setting up the piloting rig; Tongaat Hulett Sugar for the loan of their piloting column; Maidstone for their assistance with sample collections; Brian Bailey from Sugarequip (Pty) Ltd for the loan of their turbidity meter; Dr Richard Loubser for his help with instrumentation and data capture; Steve Davis for his valuable input and support of the work.

Endnote

1 Mr J.P. Lamusse, Mauritius (2012), Telephonic communication.

Abbreviations used:

abs absorbance

BT bubble disengagement tankCJ conventional defecation clear juiceDCJ direct clear juiceDJ draft juicefloc flocculantMJH mixed juice heaterMJ mixed juiceHTC heat transfer coefficientSJH scalding juice heaterSMRI Sugar Milling Research Institute NPCtcph tons cane per hourWSM white strap molasses

† This paper was presented at the 2012 SASTA annual conference and is published here with the agreement of the Society.

References

Anon (1985) Laboratory Manual for South African Sugar Factories.

3rd Edition, South African Sugar Technologists’ Association, Mount

Edgecombe, South Africa. p 262.

Chen, J.C.P. (1972) Questions frequently asked about sugar cane

diffusion. Zuckerindustrie 22(5): 261-265.

Ivin, P.C., Clarke, M.L. and Blake, J.D. (1987) Comparison of

extractives from milling and diffusion. Proc. Aust. Soc. Sug. Cane

Technol. 9: 191-200.

Jensen, C.R.C. (2001) The elimination of filtercake in a cane sugar

factory by recycling defecation muds to the extraction plant. Proc. Int. Soc.

Sug. Cane Technol. 24: 231-236.

Jensen, C.R.C. and Kitching, S.M. (2007) Options for retrofitting white

sugar milling (WSM) technologies into existing raw sugar factories. Proc.

Int. Soc. Sug. Cane Technol. 26: 1504-1512.

Jensen, P.S. (2011) Suspended solids by volume % - A quick,

comparitive method for mixed juice suspended solids analysis. Technical

Note No. 13/11, Sugar Milling Research Institute, Durban, South Africa.

Lamusse, J.P. (1980) Practical Aspects of Cane Diffusion. Elsevier:

197-253.

Lamusse, J.P. (1981) Recommendations for improving the performance

of the cane diffuser at central Tocuyo. Technical Report No. 1278 RCP,

Sugar Milling Research Institute, Durban, South Africa: 2.

Lionnet, G.R.E. (2000) An old technologist’s perspectives of new

separation technologies. Proc. S. Afr. Sug. Technol. Ass. 74: 257-260.

Lionnet, G.R.E. (2005) The effect of selected factors on percolation

in pilot diffusion columns. Proc. S. Afr. Sug. Technol. Ass. 79: 249-257.

Love, D.J. and Rein, P.W. (1980) Percolation behaviour of a cane

diffuser. Proc. Int. Soc. Sug. Cane Technol. 17: 1900-1924.

Meadows, D.M., Schumann, G.T. and Soji, C. (1998) Farewell to filters:

The recycle of clarifier muds to the diffuser. Proc. S. Afr. Sug. Technol.

Ass. 72: 198-203.

Mkhize, S.C. (2003) Clear juice turbidity monitoring for sugar quality.

Proc. S. Afr. Sug. Technol. Ass. 77: 414-422.

Payne, J.H. (1965) Cane diffusion - The displacement process in

principle and practice. American Factors Associates, Honolulu, Hawaii,

USA: 110-117.

Payne, J.H. (1968) Cane diffusion – Ring diffuser at Pioneer Mill

Company. American Factors Associates, Honolulu, Hawaii, USA: 1517-

1518.

Peacock, S.D. and Love, D.J. (2003) Clear juice heaters - Do we need




them? Proc. S. Afr. Sug. Technol. Ass. 77: 452-462.

Rein, P.W. (1995) A comparison of cane diffusion and milling. Proc. S.

Afr. Sug. Technol. Ass. 69: 196-200.

Rein, P.W. (2007) Cane Sugar Engineering. Verlag Dr Albert Bartens:

210, 173, 226.

Sahadeo, P., Lionnet, G.R.E. and Davis, S.B. (1998) The effect

of clarifier mud carryover on sugar quality. A preliminary pilot plant

investigation. Technical Report No. 1785, Sugar Milling Research Institute,

Durban, South Africa: 1.

Schäffler, K.J. (1988) Acetic acid production in cane diffusers and the

resultant effect on vapour pipe corrosion in evaporators. Proc. Conf. Sug.

Process Res.: 62-74.

Van Der Riet, C.B. and Renton, R.H. (1971) The Empangeni diffuser

installation 1967-1970. Proc. S. Afr. Sug. Technol. Ass. 69: 49-60.

Vukov, K. (1965) Kinetic aspects of sucrose hydrolysis. Int. Sug. J. 67:

172-175.

Wright, P.G. (2006) Notes on the consistency of clarifier underflow

mud. Proc. Aust. Soc. Sugar Cane Technol. 28: (see index)

APPENDIX 1

Calculations:

Sugars™ model parameters and basis:Cane throughput = 300 t/hBrix % Cane = 16%Sucrose % Cane = 13.6%Fibre % Cane = 15%

Imbibition % Fibre = 350%Juice throughput = 380 t/h (including mud recycle)Sucrose % Juice = 11.1%Clarifier configuration = Mud recycled to diffuserEvaporator configuration = 5th effect with condensate flash to following effectHeating vapour = V1Crushing hours per year = 4200Sugar price (R/t) = R4100/ton (24.71 c/lb. as of 02/04/2012)Steam/bagasse ratio = 2Bagasse price T/t (coal equivalent) = R208Exchange rate = ±R8/1US$ (02/04/2012)

Steam saved if no flashing required:Flash temperature = 104°CHeating vapour = V1Exhaust steam saved = 1.61 t/hAnnual Rand savings = 1.61 x 4200 x 208/2Annual Rand savings = R703 248

Steam saved if clarifier heat losses removed:Clarifier temperature drop = 2°C (100 to 98°C)Exhaust steam saved = 1.38 t/hAnnual Rand savings = 1.38 x 4200 x 208/2Annual Rand savings = R602 784

APPENDIX 2 - Figure 19. Turbidity and percolation chart of piloting run 30/09/2011



Sucrose saved if clarifier inversion losses removed (Vukov model):Brix % Juice = 13.04Average temperature = 99°CpH = 7.1Residence time (mins) = 60 Inversion % = 0.18Sucrose inverted per year (t) = 0.0018 x 380 x 0.111 x 4200 = 319Annual Rand savings = 319 x 4100Annual Rand savings = R1 307 411

Steam saved if V2 used instead of V1 in final juice heaters:Temperature rise in heater = 9°C (89 to 98°C)Exhaust steam saved = 1.51 t/hAnnual Rand savings = 1.51 x 4200 x 208/2Annual Rand savings = R659 568

APPENDIX 2

Results and discussion of a single run

Figure 19 shows an example of the logged data from one of the runs. For this run, MJ, diluted with water to 8 brix, was used as the starting material. After the initial batch clarification, ~5 kg of mud was removed from the bottom of the heated tank before the juice was circulated through the column. This was to reduce the solids load imposed on the bed. The 5 kg of mud was later added to the column to observe its effect on turbidity and percolation rate.

A detailed commentary to the chart in Figure 19 is given in Table 7.

The samples DCJ1 to DCJ5, which were removed during the trial as indicated in Figure 19, were kept for laboratory analysis. The results from the analysis are shown in Table 8.

Table 7. Commentary to turbidity and percolation chart of piloting run 30/09/2011

Time (mins) Commentary

0 The tank valve is opened and juice flows from the tank to the diffusion column.

1 The first juice from the column flows through the turbidity meter.

3 Juice turbidity is dropping but bubbles into the meter give a false reading.

3 All the juice has passed once through the cane bed.

5 The DCJ absorbance is equal to that of mill CJ (measured after the DCJ run). Percolation is ~0.2 m3/m2/min.

7 The first sample of juice (DCJ 1) is taken for lab analysis.

11 All the juice has passed twice through the cane bed.

13 The second sample of juice (DCJ 2) is taken for lab analysis.

19 The ‘lifting screw’ is removed from the bed.

20 Percolation rate increases from 0.1 to 0.8 m3/m2/min.

20 All the juice has passed three times through the cane bed.

20 Turbidity increases to 5 abs units as mud trapped in the bed is released through bed agitation with the lifting screw.

26 Turbidity is once again decreased to below the mill CJ reading however percolation rate is now ~0.75 m3/m2/min.

34 5 kg of mud removed earlier is added into the tank.

34-38 Bubbles entrained in the juice corrupted the absorbance readings. The juice turbidity trend can however be seen to have been negligibly influenced by the addition of mud into the tank.

38 The fourth sample of juice (DCJ 4) is taken for lab analysis.

39 Percolation rate dropped from 0.5 m3/m2/min to 0.3 m3/m2/min as a result of extra mud addition.

46 Poured 5 kg of mill CJ into the tank. A spike in the turbidity shows the mill clear juice to have higher turbidity than the circulating juice.

52-64 Bed manipulation attempted from the top of the column. No increase in percolation rate resulted, bud interruptions in the turbidity were witnessed.

64 The fifth sample of juice (DCJ 5) is taken for lab analysis.

64 The tank valve is shut and pump stopped.

72 Mill CJ (collected at the same time as the cane) is poured through the turbidity meter in order to measure its absorbance.

Table 8. Laboratory results of piloting run 30/09/2011

Mill MJ DCJ1 DCJ2 DCJ3 DCJ4 DCJ5 Mill CJ

Time into run (mins) 0 7 13 19 38 64 −

ICUMSA turbidity 15 406 13 085 9 553 4 138 7 520 7 534 11 307

% of CJ turbidity 136% 116% 84% 37% 67% 67% 100%

Online turbidity (abs) 3 1.6 0.85 0.5 0.7 0.25 2.20




abstract

Bagasse stockpile operations have the potential to lead to adverse environmental and social impacts. Dust releases can cause occupational health and safety concerns for factory workers and dust emissions impact on the surrounding community. Preliminary modelling showed that bagasse depithing would likely reduce the environmental risks, particularly dust emissions, associated with large-scale bagasse stockpiling operations. Dust emission properties were measured and used for dispersion modelling with favourable outcomes. Modelling showed a 70% reduction in peak ground level concentrations of PM10 dust (particles with an aerodynamic diameter less than 10 µm) from operations on depithed bagasse stockpiles compared to similar operations on stockpiles of whole bagasse. However, the costs of a depithing operation at a sugar factory were estimated to be approximately $2.1 million in capital expenditure to process 100,000 t/y of bagasse and operating costs were $200,000 p.a. The total capital cost for a 10,000 t/y operation was approximately $1.6 million. The cost of depithing based on a discounted cash flow analysis was $5.50 per tonne of bagasse for the 100,000 t/y scenario. This may make depithing prohibitively expensive in many situations if installed exclusively as a dust control measure.

Keywords: bagasse, depithing, dust, pith, stockpile

Un estudio preliminar sobre las consecuencias ambientales y económicas de una operación de desmedulado en fábrica

Las operaciones de acopio de bagazo tienen el potencial de producir impactos ambientales y sociales negativos. La liberación de polvo puede

generar ansiedad por la salud ocupacional y la seguridad de los obreros de la fábrica asimismo que los efectos sobre la comunidad vecina. Los

modelos preliminares mostraron que el desmedulado del bagazo posiblemente disminuyera los riesgos ambientales, particularmente las emisiones

de polvo, asociados con el acopio en gran escala de bagazo. Se midieron las propiedades de la emisión de polvos y se usaron para modelar

la dispersión con resultados favorables. El modelado mostró una reducción del máximo de concentraciones del polvo PM10 (partículas con un

diámetro aerodinámico menor de 10 µm) a nivel del suelo de las operaciones con bagazo desmedulado en comparación con operaciones similares

en acopios de bagazo entero. No obstante los costos del desmedulado en un ingenio azucarero se estimaron en aproximadamente $2,1 millones

en desembolso de capital para procesar 100.000 t/año de bagazo y los costos operativos eran de $200.000 por año. El costo total de capital para

una operación de 10.000 t/a era de aproximadamente $1,6 millones. Los costos del desmedulado en un análisis de flujo de caja descontado fue

de $5,50 por tonelada de bagazo para una situación de 100.000 t/a. Esto puede hacer que el desmedulado sea prohibitivamente caro en muchas

situaciones, si se instala exclusivamente como medida del control de polvo.

Um estudo preliminar sobre as consequências ambientais e econômicas da operação de desmedulamento no engenho de açúcar

As operações de armazenamento de bagaço têm o potencial de gerar impactos ambientais e sociais adversos. A liberação de poeira pode gerar

preocupações sobre a saúde e segurança dos trabalhadores da usina, além de causar impacto nas comunidades locais. Uma modelagem preliminar

mostrou que o desmedulamento do bagaço poderia reduzir os riscos ambientais, em particular em relação às emissões de poeira, associados com

as operações de armazenamento de bagaço em grande escala. As propriedades de emissão de poeira foram medidas e usadas para a modelagem

de dispersão com resultados favoráveis. A modelagem mostrou uma redução de 70% nas concentrações de pico no solo de poeira PM10 (partículas

com diâmetros aerodinâmicos menores do que 10 µm) nas operações de armazenamento de bagaço desmedulado em comparação com operações

semelhantes de armazenamento do bagaço inteiro. No entanto, os custos da operação de desmedulamento no engenho de açúcar foram estimados

em aproximadamente 2,1 milhões de dólares em despesas de capital para processar 100.000 toneladas/ano de bagaço e os custos de operação

foram estimados em 200.000 por ano. O custo de capital total para uma operação de 10.000 toneladas/ano é de aproximadamente 1,6 milhões

de dólares. O custo do desmedulamento baseado na análise do custo do fluxo de caixa descontado é de 5,50 dólares por tonelada de bagaço

para o cenário de 100.000 toneladas/ano. O que pode tornar o desmedulamento inviável financeiramente em muitos casos se ele for instalado

exclusivamente como uma medida de controle de poeira.

A preliminary study into the environmental and economic consequences of a sugar factory depithing operation †

Queensland University of Technology, Brisbane, Australia.


T.J. Rainey *, A.P. Mann, C.H. Bakir and I.M. O’Hara


Introduction

As the industry moves towards increasing revenue from bagasse, through electricity generation or value-added products such as bioethanol, there is an increasing requirement for larger-scale bagasse storage to permit operations to continue outside of the crushing season.

The potential environmental hazards associated with dust, groundwater seepage and leachate from bagasse stockpiling operations, and the impact of these hazards on the surrounding environment and communities, are reported in a guideline published by the Queensland Government Department of Environment and Resource Management (DERM, 2010). Depithing is one option for mitigating dust as a potential hazard.

Smaller bagasse particles (pith) are more likely to become and remain airborne during typical handling operations. Airborne dust has workplace health and safety implications for the sugar factory and can also generate complaints from surrounding communities.

The presence of the pith in bagasse has operational impacts also. Pith fills the voids between larger fibre particles in a bagasse stockpile, making the stockpile less porous and increasing bulk density.

Bagasse which has not been separated into pith and depithed bagasse is herein referred to as whole bagasse. If pith can be economically removed from whole bagasse prior to stockpiling it is likely that less dust will be produced during bagasse stockpile operations.

In addition it is possible that free water in a stockpile will drain more quickly, reducing water retention and hence reducing bagasse decomposition and the generation of decomposition products. This may lead to reduced impacts associated with groundwater seepage and leachate from bagasse stockpiles. These and other potential impacts, such as spontaneous combustion, are discussed in other literature written by the authors (O’Hara et al., 2012; Rainey et al., 2012).

This paper reports on the modelling work to assess the likely beneficial effects on dust emissions from stockpiling of depithed bagasse and the capital and operational costs of depithing bagasse for large-scale storage.

The nature of pith

During the processes of shredding and milling of sugarcane, pith is liberated. On a dry, water insoluble basis, the resulting bagasse from the extraction process consists of pith from the centre of the plant and other fibres (these other fibres are here-on referred to as ‘fibre’). The pith makes up around 40% of bagasse (Rainey, 2009). Differentiating pith from the fibre is particularly important in the context of this article.

The pith portion of the plant is anatomically quite different to the fibre portion. Pith is composed of thinwalled parenchyma cells (Giertz and Varma, 1979), that are squarer (i.e. lower aspect ratio) with a maximum length in the order of 520 µm (Rainey et al., 2009) and have an average diameter of 140 μm (Paul and Kasi Viswanathan, 1998). Cells found in the fibre are typically 1.0 to 1.2 mm in length and 20 μm in diameter, with a wall thickness of 5 μm and a lumen diameter of 10 μm (Paul and Kasi Viswanathan, 1998; Rainey et al., 2010).

Commercial depithers

Depithing bagasse is essential for making high quality bagasse-based paper and commercial depithing equipment was developed for this industry, which is worth around $5 billion (Rainey, 2009). Conventional depithing equipment can be readily bought off-the-shelf from suppliers and supplier information and quotes were used in this study.

Conventional depithing equipment used at pulp mills removes only about 30% of the weight of bagasse (Atchison, 1971a; Atchison, 1971b; Rao, 1997), suggesting that commercial depithers remove only about 75% of the pith component.

Historically, there were several different depither designs available from suppliers. Atchison (1971a), Rao (1997) and Paturau (1989) provide a good overview of these technologies. Modern depithers supplied from most manufacturers are typically composed of hammers mounted on a vertical shaft (Figure 10).

The rotating assembly is mounted with straight hammers and operates at high speed, typically 1000-1800 r/min. Whole bagasse is fed into the top of the unit and it is hit by the hammers, opening up clumps of bagasse. The pith is thrown through a screen while the fibre falls down the centre of the unit to a conveyor. The pith and fibre are conveyed away separately.

Some older depither designs that were available from suppliers were mounted on a horizontal shaft, such as the Horkel (Paturau, 1989) or SPM depithers (Atchison, 1971a). The widespread use of depithers in India for paper manufacture makes it likely that several of the older designs remain in use.

The depither hammers need to be periodically maintained and replaced. Typically, hammers may last several weeks depending upon bagasse feed rate and quality; however, it was reported in one particularly problematic instance that the hammers had to be replaced every three days (Koen, 1980). Some designs allow for isolating and replacing groups of hammers, rather than replacing the hammers individually.

Depithers are usually arranged in banks. Whole bagasse enters the depithing station from the sugar factory and falls

Whole bagasse enters

Pith passes screen

Fibre

Figure 1. Sketch of a depither (Lois et al., 1980)

A preliminary study into the environmental and economic consequences of a sugar

factory depithing operation


through the depithers through a series of chutes. The bagasse may be fed into the depithers by a screw or a slat conveyor. Inside the depither, the pith is separated from the fibre, combined with pith from other depither units and conveyed away on common conveyor belts.

For paper production, depithed bagasse is stored wet (>80% moisture) for up to 12 months as this maximises the quality of the fibre for paper manufacture. Moist depithed bagasse is rarely stored and its storage behaviour is not well documented in the literature. It is not known if there are any factories currently storing moist depithed bagasse.

Methodology

Dust dispersion modelling

Fresh bagasse was obtained from Condong Mill in September 2010. The size distribution of pith and whole bagasse was measured as it is a key input into the dust dispersion model. The size distribution of depithed bagasse was calculated based on the size distributions for whole bagasse and pith.

A hammer mill style depither was not available for this project and hence depithing trials were carried out using a vibrating sieve. A sieve with an aperture of 1.575 mm was used and pith was defined as being the component of the bagasse that passed through a screen of this size. A 1 kg bagasse sample was placed into the sieve, the vibrating motor was turned on and the bagasse was gently mixed by hand. The smaller pith particles passed through the sieve and were collected. The samples were weighed before and after each depithing run to determine the proportion of pith separated from the bagasse.

The time taken to completely depith the whole bagasse was measured. The average time for complete depithing was approximately 210 seconds. At this time it was observed that small fibre strands were beginning to pass through the sieve with very little pith remaining in the sample. Using this technique, almost all the pith could be removed (~40% of the bagasse) and analysed. Sieving bagasse in the laboratory removed a higher proportion of larger pith than a commercial depither (~40% of total material removed in a sieve compared with ~30% removed in a commercial depither). However, this has only a minor impact on the modelling of dust concentrations conducted in this study because sieving removes more of the larger pith material.

The dispersion modelling code AUSPLUME was used to predict ground level concentrations of particles with equivalent spherical diameter less than 10 µm (PM10) produced during operations on a 150 m by 110 m stockpile of bagasse or depithed bagasse. Ground level concentration is defined as the concentration in air of a pollutant to which a human being is normally exposed, i.e. between the ground and a height of some 2 m above it. The focus of the dust modelling in this paper is on PM10 dust particles rather than larger nuisance dust particles.

Generally pith particles have smaller aspect ratios (< 2) than fibre particles (>2) but it should be noted that there will be a wide range of particle shapes in any sample of bagasse, pith or depithed bagasse. This variability makes it difficult to accurately determine the size distribution of bagasse, pith or depithed bagasse.

Laser particle size analysis is the most commonly used method for determining the size distribution of fine particles. When the particles are spherical the correct diameters are reported but when the particles are irregularly shaped, laser particle size analysis becomes less accurate and the reported diameters are those of equivalent volume spheres.

Sieving is frequently used to determine particle size distributions for bagasse but sieving can often give inconsistent results for particles with large aspect ratios (like fibre particles) as the particle passage through a screen is affected by particle orientation.

Sieving is also unsuitable for very fine particles because the small holes required in the screen would become blocked. In this work it was decided to use laser particle sizing to determine the size distribution of a pith sample and use sieve analysis data to determine the size distribution of a whole bagasse sample.

To make the bagasse particle size distribution consistent with the pith particle size distribution, the common assumption of bagasse particles being cylinders was made and a diameter of an equivalent volume sphere (deq) was calculated for the bagasse particles using:

where d is the cylindrical particle diameter and l is the cylindrical particle length.

The geometry (diameter, length) and size distribution for whole bagasse used in this study were based on sieve, micrometer and microscopic analyses. With the whole bagasse and pith size distributions both expressed in terms of deq an approximate size distribution for depithed bagasse could be determined. The size distributions, based on deq, for whole bagasse, pith and depithed bagasse are shown in Table 1.

The dust dispersion model was calibrated using measured dust fallout data from a similarly sized stockpile during a period with stockpile operations. The simulations used meteorological data files from a typical Queensland sugar milling region but did not take into account the effects of surrounding buildings or trees. As only PM10 particles were modelled in this work, fallout of larger dust particles was ignored.

3 2

23

lddeq = (1)

Table 1. Mass fractions (%) associated with each size range for whole bagasse, pith and depithed bagasse. Size ranges based on the diameter of an equivalent volume sphere (deq)

Size group Whole bagasse

Pith Depithed bagasse

< 10 µm 0.65 1.43 0.19

10 µm – 50 µm 2.03 3.83 0.76

50 µm – 100 µm 2.64 6.56 0.95

100 µm – 500 µm 25.81 55.79 7.59

500 µm – 1000 µm 32.34 27.54 44.91

1000 µm – 5000 µm 34.78 4.85 43.29

5000 µm – 10,000 µm 1.65 0.00 2.19

> 10,000 µm 0.10 0.00 0.12

A preliminary study into the environmental and economic consequences of a sugar factory depithing operation


All simulations carried out in this work used the Pasquill Gifford horizontal and vertical dispersion curves adjusted for surface roughness. The modelled plume rise took buoyancy into account. An averaging time of 24 h was used. The modelled stockpile had dimensions of 150 m length in the west to east orientation.

Economic analysis modelling

Capital and operating costs of a depithing operation were estimated for installation at a typical sugar factory. Two different sized depithing operations were considered for costing: a larger installation for processing 100,000 t/y of whole bagasse and a smaller depithing operation of 10,000 t/y.

Quotes and budgetary pricing for equipment were obtained from equipment manufacturers. Quotes were provided in US dollars and Euros as well as in Australian dollars. Assumptions in the analysis included: the depithing operation runs for 150 days per year; time efficiency is 95%; and the commercial depither removes 30% of the whole bagasse. Long term average exchange rates of A$1 buys US$0.80 and €0.66 are used in this study.

The installation costs were estimated using published ‘ratio fac-tors’ (herein referred to as ‘cost factors’) for solid processing plant (Peters et al., 2003).

A discounted cash flow (DCF) analysis was performed to calculate the amortised cost of depithing one tonne of bagasse. The cost was calculated by assigning a value to bagasse which would be required to achieve a neutral Net Present Value over the life of the project. The analysis used the 100,000 t/y scenario over 15 years with a 15% discount rate and 10% scrap value. The capital and operating costs calculated in the following sections were used.

100,000 t/y installation

A depithing operation processing a whole bagasse feed rate of 100,000 t/y will process on average 29 t/h of whole bagasse. Two standard 16 t/h depither units were selected for cost estimation (10% additional capacity) and ancillary equipment, such as motors and hammers, were sized on that basis. A conceptual Process Flow Diagram (PFD) of the 100,000 t/y depithing installation is presented in Figure 2.

Bagasse is withdrawn from the conveyor that transports bagasse to the bagasse outloading station. It is split between the two depither units and fed into each depither through a feed chute. The depithed bagasse and pith from the two depithers are transported by two

conveyors; one for depithed bagasse and one for pith.The depithed bagasse is transported by truck to a stockpile

and the pith is returned immediately by conveyor to the bagasse conveyor feeding the boilers. Other general assumptions are provided in Table 2.

10,000 t/y installation

The nominal whole bagasse feed rate for a 10,000 t/y installation is 3 t/h. It was assumed that the PFD would be similar to the 100,000 t/y case with the exception that a single smaller depithing unit and a smaller motor would be required. Other than that, the assumptions used for the 100,000 t/y installation were mostly the same as for the 10,000 t/y installation.

Notably, the cost of the conveyors was assumed to be the

Table 2. General assumptions for determining the capital cost of a 100,000 t/y depithing operation

Parameter Assumption Comments

Depither capacity 16 t/h ~10% above that required for 100,000 t/y; 30% pith yield

No. of depithers and motors required 2

Price per depither $69,500

Price per motor $18,000 Supplier quote

Cost of hammers $24,000 2 sets, exc. freight

Working capital– hammers $36,000 First changeover + spare = 3 additional sets, exc. freight

Conveyor length total 60 m

Price of conveyors per metre $4250 Supplier quote

Conveyors installation $280,500 Supplier quote calculated, exc. freight.

Table 4. Assumptions for operating costs for two depithing installations

Parameter 100,000 t/y 10,000 t/y

General maintenance (% capital p.a.) 3.50 3.50

Electricity price ($/MWh) 80 80

Power consumption (kW) 400 40

Total energy used (MWh) 1368 136.8

Table 3. Installed cost factors (% of equipment cost; Peters et al., 2003)Parameter Cost factor (%)

Installation 45

Freight 3

Instrumentation and control 16

Piping 16

Electrical 20

Building 25

Yard improvements 15

Services 40

Engineering and supervision 33

Construction expenses 39

Legal 4

Contingency 35

Working capital– unspecified 15




same as for the 100,000 t/y case and the commissioning of the depithers is a fixed price and is thus independent of the installed capacity.

The cost factors provided in Table 3 are for solid processing plant (Peters et al., 2003). Commissioning of the depithers by the supplier’s engineer is assumed to be a fixed cost and therefore a cost factor was not applied to commissioning.

In addition to the capital costs, the operating and mainte-nance costs were also assessed. Hammer replacement costs are based on supplier information. Apart from hammers and general

maintenance costs, the other main operating cost is electricity. The assumptions for the operating cost estimation are shown in Table 4.

Results and discussion

Plume dispersion modelling

Figure 3 shows a contour plot of the predicted 24 h average PM10 ground level dust concentration (mg/m3)

Figure 2. Conceptual Process Flow diagram for a 100,000 t/y depithed bagasse stockpile

Figure 3. Title Plan view of the predicted PM10 24 h average ground level dust concentration (µg/m3) distribution around the modelled 150 m by 110 m stockpiles for (a) whole bagasse and (b) depithed bagasse. Dust concentrations are relative to normal background levels (without any stockpiling or transport operations). The positive y-axis corresponds to north. The red rectangle denotes the stockpile

(a) Whole bagasse

(b) Depithed bagasse



distributions around the (a) whole bagasse and (b) depithed bagasse stockpiles.

The predicted concentrations in Figure 3 are those due to typical bagasse stockpiling and transport operations and are therefore relative to the normal background dust concentrations.

Note the air quality objective in the Environmental Protection (Air) Policy 2008 (Queensland Government, 2012) is 50 μg/m3 for PM10 at ground level over a 24 h average. In all cases the predicted peak ground level PM10 dust concentration was about 80 m from the edge of the stockpile and in a north-westerly direction.

The peak 24 h average concentrations of PM10 dust for each of the stockpiles are shown in Table 5.

Depithing reduced peak 24 h PM10 dust concentration from 32.4 µg/m3 to 9.4 µg/m3, a reduction of 71%.

Economic modelling

The capital cost of a 100,000 t/y bagasse depithing operation was estimated to be $2.10 million. The highest equipment cost in the depithing operation is the conveyors. A budget pricing for conveyors of $4675 per metre was used. For the conveyor cost estimation, it was assumed that 60 m of industrial conveyors would be required for the depithing operation, i.e. $280,000 (inc. GST and excluding freight). This is a very significant proportion of the total equipment cost ($516,000) and hence the total capital cost of the equipment is highly sensitive to the length and type of the conveyors. Table 6 shows the breakdown of the costs associated with installation. The total installed cost was 4.1 times the cost of the purchased equipment.

The operating and maintenance costs are estimated to be approximately $187,000 per year as shown in Table 7. A complete set of hammers contains 44 knives. The hammers consist of one set of hammer knives which are fixed to the shaft via the knife holders. The knives can be turned which means each set of knives can be used twice. Knives can process around 12,000 t before they need to be reinstalled; therefore a set of hammers lasts for around 24,000 t. Information provided by suppliers indicates that it typically takes two fitters 10-12 h to replace a set of knives.

The capital cost of the 10,000 t/y unit was $1.6 million which is also shown in Table 6. The savings by reducing the size of the depithing operation are relatively minor. The major savings are in the cost of the depither, the hammers, the motor, the working capital and the associated installation costs.

It was assumed that the cost to purchase and install the conveyors, which is the largest single equipment cost, would not change and hence the capital cost is very sensitive to this assumption.

The operating costs for the 10,000 t/y case was around $40,000 per year as shown in Table 7. A set of hammers would be expected to last for two seasons.

The DCF analysis indicated that the cost of depithing is around $5.50 per tonne of bagasse.

Additional considerations

As well as reducing dust levels, there are energy implications for depithing. Depithed bagasse has less capacity to hold water which may result in lower moisture bagasse going into the boiler and less bagasse degradation, increasing combustion efficiency.

However, smaller particles such as pith burn more efficiently but have higher ash and water content. The combustion of pith and depithed bagasse is discussed elsewhere in these Proceedings (Mann and O’Hara, 2012).

Preliminary modelling (not reported here) suggests that there is unlikely to be a significant change in the risk of self-heating of bagasse stockpiles resulting in spontaneous combustion of the stockpile for a depithed bagasse stockpile compared to a whole bagasse stockpile; however, further assessment of this risk is required.

Table 5. Predicted peak 24 h average PM10 dust concentrations (µg/m3) around the modelled bagasse and depithed bagasse stockpiles

Bagasse stockpile Depithed bagasse stockpile

32.4 9.4

Table 6. Capital costs ($) for 100,000 and 10,000 t/y depithing operations

100,000 t/y 10,000 t/y

Total equipment cost 515,550 392,750

Installation 231,998 176,738

Freight 15,467 11,783

Instrumentation and control 82,488 62,840

Piping 82,488 62,840

Electrical 103,110 78,550

Building 128,888 98,188

Yard improvements 77,333 58,913

Services 206,220 157,100

Engineering and supervision 170,132 129,608

Construction expenses 201,065 153,173

Legal 20,622 15,710

Commissioning cost 6,496 6,496

Contingency 180,443 137,463

Working capital 77,333 58,913

Total additional costs 1,584,079 1,208,311

Total capital expenditure 2,099,630 1,601,060

Table 7. Operating costs ($) for the 100,000 and 10,000 t/y cases

100,000 t/y 10,000 t/y

General maintenance 18,044 13,746

Electricity cost 109,440 10,944

Labour 10,000 10,000

Hammers 50,000 5,000

Total operating costs 187,484 39,690




Dust will also be generated in the depithing operation including the transfer operations for bagasse, depithed bagasse and the return of pith to the bagasse conveyor system. Engineering controls will be required to ensure that dust generated in the depithing operation is well controlled.

Prior to recommending depithing as a viable and lower risk storage strategy for large scale bagasse storage, validation of the modelling work including the impacts on leachate generation and self-heating are required.

This work would include the construction and assessment of a depithed bagasse stockpile. Depithing also has implications for the bulk density and compaction of the stockpile, permeability and water holding capacity, which are the topic of another article (Rainey et al., 2012).

Conclusion

The dust dispersion modelling carried out in this work predicted that the model stockpile of depithed bagasse would produce lower concentrations of very fine (PM10) dust particles than similar operations on a whole bagasse stockpile. The costs associated with a depithing operation were considered for a 100,000 t/y operation and a 10,000 t/y operation.

It was found that the capital cost of the depithing installa-tion modelled was $2.1 million and $1.6 million respectively, although this will vary significantly between sites for a commercial installation.

Amortised over the life of the plant, this corresponded to a cost of $5.50 per tonne of bagasse for the 100,000 t/y scenario. For factory operations, the size and cost of the conveyors is a critical cost factor as it accounts for around 50% of the purchased equipment costs. A change in the length or type of conveyor significantly affects the overall capital cost.

Particularly for small scale bagasse stockpiles, unless the con-veyor cost can be significantly reduced, depithing may be prohibitively expensive if installed exclusively as a dust control measure.

Apart from reducing dust emissions from stockpile opera-tions, there are other impacts which must be considered including combustion efficiency, control of dust at the depithing operation, leachate generation, self-heating and cost. These impacts have been published elsewhere by the authors (O’Hara et al., 2012; Rainey et al., 2012; Mann and O’Hara, 2012).

Acknowledgements

The project participants wish to acknowledge receipt of project funding from the Australian Government and the Australian sugarcane industry as provided by the Sugar Research and Development Corporation.

Revco Australia assisted with information on depithing equipment. Conveyor and General Engineering assisted with information on conveyors. The authors wish to acknowledge the contributions made by Ms Wanda Stolz and Mr Neil McKenzie in assisting the work.

† This paper was presented at the 2012 Australian Society of Sugar Cane Technologists annual conference and is published here with the agreement of the Society.

References

Atchison, J.E. (1971a) Review of bagasse depithing. Proceedings of

the International Society of Sugar Cane Technologists XIV: 1202-1217.

Atchison, J.E. (1971b) Review of progress with bagasse for use

in industry. Proceedings of the International Society of Sugar Cane

Technologists XIV: 1189-1201.

DERM (2010) Managing impacts from the bulk storage of bagasse.

Guideline renewable energy. Department of Environment and Resource

Management. http://www.derm.qld.gov.au/register/p01756aa.pdf.

(accessed 31 July 2011).

Giertz, H.W. and Varma, R.S. (1979) Studies on the pulping of bagasse

and the influence of pith on paper properties. In: Non-wood plant fiber

pulping progress report: 53-69. (Tappi Press: Atlanta).

Koen, A. (1980) Reducing maintenance costs of shredder hammers

and cane knives. Proceedings of the South African Sugar Cane

Technologists’ Association 54: 45-47.

Lois, J.A., Suarez, R., Garcia, O.L. (1980) Some aspects of depithing

and storage of bagasse in Cuba. Proceedings of the International Society

of Sugar Cane Technologists XVII: 2462-2471.

Mann, A.P. and O’Hara, I.M. (2012) Predicting the effects of bagasse

depithing operations on boiler combustion performance. Proceedings

of the Australian Society of Sugar Cane Technologists 34 (these

Proceedings).

O’Hara, I.M., Mann, A.P., Rainey, T.J., Bakir, C.M. and Farrell, T. (2012)

Reducing the economic and environmental risks of large scale bagasse

storage through depithing. QUT 039. Sugar Research and Development

Corporation, Brisbane.

Paturau (1989) By-products of the cane sugar industry. An introduction

to their industrial utilisation. 3rd edn. (Elsevier: Amsterdam).

Paul, S.K. and Kasi Viswanathan K.S. (1998) Influence of pith on

bagasse pulp, paper and black liquor properties. IPPTA Journal 10(3): 1-8.

Peters, M.S., Timmerhaus, K.D. and West, R.E. (2003) Plant design

and economics for Chemical Engineers. 5th edn. (McGraw Hill: New

York).

Queensland Government (2012) Environmental Protection (Air) Policy

2008, reprint 1A. Office of the Queensland Parliamentary Council. http://

www.legislation.qld.gov.au/LEGISLTN/CURRENT/E/EnvProtAirPo08.pdf.

(accessed 1 February 2012).

Rainey, T.J. (2009) A study into the permeability and compressibility

properties of Australian bagasse pulp. PhD Thesis. Queensland

University of Technology, Faculty of Built Environment and Engineering,

Brisbane.

Rainey, T.J., Doherty, W.O.S., Brown, R.J., Martinez, D.M. and Kelson,

N.A. (2009) An experimental study of Australian sugarcane bagasse pulp

permeability. Appita Journal 62: 296-302.

Rainey, T.J., Doherty, B., Martinez, D.M., Brown, R. and Kelson, N.A.

(2010) The effect of flocculants on the filtration properties of bagasse pulp.

Tappi Journal May: 7-14.

Rainey, T.J., O’Hara, I.M., Mann, A.P., Bakir, C.H. and Plaza, F. (2012)

Effect of depithing on the properties of bagasse for large scale stockpiling.

Process Safety and Environmental Protection (at press).

Rao, M. (1997) Industrial utilisation of sugar cane and its co-products.

(ISPCK Publishers and Distributers: New Delhi).



Introduction

Sugarcane mosaic, one of the most important viral diseases of sugarcane reported widely in the world (Grisham, 2000). The impact of mosaic on sugarcane varies among regions and even

in the countries where it is not a major problem, it is a quarantine disease. Mosaic disease of sugarcane was first reported from India (Barber, 1921). Although that time its economic impact was not realized, later it was found to seriously affect sugarcane production. Incidence of mosaic disease is almost 100% on

Diagnosis of Sugarcane streak mosaic virus using recombinant coat protein antiserum in sugarcane

Plant Pathology Section, Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore 641007, India.


R. Viswanathan *, V. Ganesh Kumar, R. Karuppaiah, M. Scindiya and C. Chinnaraja

abstract

Sugarcane streak mosaic virus (SCSMV) is the most widespread virus associated with sugarcane mosaic in India and other Asian countries. After characterization of the virus, detailed studies were carried out to express the virus coat protein (CP) in an expression vector along with maltose binding protein (MBP) as a fusion protein. Later polyclonal antisera were produced against recombinant SCSMVcp and the serum detected the recombinant MBP-SCSMV-CP fusion protein upto 1:40,000 dilutions in direct antigen coating (DAC)-ELISA and sensitivity of the antiserum was found to be as low as 2.5 ng in ELISA. Further, in the assays the serum detected the virus antigen from infected leaf extracts diluted to 1:10,000. Subsequently the efficiency of the new antiserum was validated with 349 leaf samples collected from 332 sugarcane cultivars showing asymptomatic to varying degrees of mosaic/streak mosaic symptoms by DAC-ELISA. Among them, 251 leaf samples were found to be positive. This assay established that the SCSMVcp antiserum is highly efficient to detect SCSMV infection in naturally infected / asymptomatic sugarcane field samples. The polyclonal antiserum produced in this study will serve as an important resource for indexing of sugarcane tissue culture and mother stock materials for SCSMV infection.

Keywords: DAC-ELISA, recombinant antiserum, Sugarcane streak mosaic virus

Diagnosis del virus mosaico del rayado del maíz de la caña de azúcar utilizando en la caña de azúcar un antisuero recombinante de la proteína de la cubierta

El virus mosaico del rayado del maíz de la caña de azúcar (SCSMV) es el virus asociado con el mosaico de la caña de azúcar en la India y otros países asiáticos. Después de la caracterización del virus se efectuaron estudios minuciosos para expresar la proteína de la cubierta del virus (CP) en un vector de expresión junto con la proteína de unión de la maltosa (MBP) como proteína de fusión. Posteriormente se produjeron antisueros policlonales contra el recombinante SCSMVcp y el suero detectó la proteína recombinante de fusión MBP-SCSMV-CP hasta diluciones de 1:40.000 en un ELISA directo por capa de antígeno (DAC)-ELISA y se encontró que la sensibilidad del antisuero fue de hasta 2,5 ng en ELISA. Más aún, en los ensayos el suero detectó el antígeno del virus en extractos de hojas infectadas, diluidos 1:10.000. Posteriormente, la eficiencia del nuevo antisuero fue validada por DAC-ELISA con 349 muestras de hojas recogidas de 332 cultivares de caña de azúcar que eran asintomáticos o mostraban diversos grados de síntomas mosaico/raya del virus mosaico. Entre ellas 251 muestras de hojas dieron positivo. Este ensayo estableció que el antisuero SCSMVcp es altamente eficiente para detectar una infección por SCSMV en muestras de campo de caña naturalmente infectada, asintomática. El antisuero policlonal producido en este estudio servirá como un importante recurso para determinar la infección por SCSMV en cultivo de tejidos de caña de azúcar y en materiales madre en depósito.

Diagnóstico do vírus mosaico da cana-de-açúcar usando antissoro de proteína recombinante na cana-de-açúcar

O vírus mosaico da cana-de-açúcar (SCSMV) é o vírus mais comum associado com o mosaico da cana-de-açúcar na Índia e outros países asiáticos. Após a caracterização do vírus, foram realizados estudos detalhados para expressar a proteína de revestimento (CP, do inglês: coat protein) do vírus em um vetor de expressão, juntamente com a proteína de ligação de maltose (MBP, do inglês: maltose binding protein) como uma proteína de fusão. Posteriormente, foram produzidos antissoros policlonais contra o recombinante SCSMVcp e o soro detectou a proteína de fusão recombinante MBP-SCSMV-CP em diluições de até 1:40.000 em revestimento de antígeno direto (DAC, do inglês: direct antigen coating)-ELISA e a sensibilidade do antissoro foi tão baixo quanto 2,5 ng no ELISA. Além disso, nos ensaios o soro detectou o antígeno do vírus no extrato de folhas contaminadas diluídas em 1:10.000. Posteriormente, a eficiência do novo antissoro foi validada com amostras de 349 folhas de 332 cultivares de cana-de-açúcar que apresentavam graus diversos de sintomas do mosaico/mosaico listrado pelo DAC-ELISA, incluindo amostras assintomáticas. Entre elas, 251 amostras de folhas tiveram resultados positivos. Este ensaio estabeleceu que o antígeno SCSMVcp é altamente eficiente na detecção de infecção de SCSMV em amostras de campo de cana-de-açúcar infectadas naturalmente ou assintomáticas. O antígeno policlonal produzido neste estudo servirá

como uma fonte importante para a indexação de culturas de tecidos da cana-de-açúcar e como base de materiais de estoque para infecções SCSMV.


sugarcane in the country and it results in significant yield losses (Agnihotri, 1996). Impact of mosaic on degeneration of popular sugarcane varieties like Co 740 and CoC 671 was also established (Viswanathan and Balamuralikrishnan, 2005). Although we record mosaic, severe streaks, streak mosaic, yellow splotches etc. in the leaves, the disease is collectively called as mosaic and the associated virus(es) cannot be related to the disease symptoms due to overlaps in disease symptoms.

Earlier Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) with numerous strains were associated with the disease (Koike and Gillaspie, 1989). Later Hall et al. (1998) found a new Potyviridae member named Sugarcane streak mosaic virus (SCSMV) from the sugarcane germplasm intercepted in the USDA Sugarcane Quarantine on material exhibiting mosaic symptom, which was imported from Pakistan. Subsequently, Hema et al. (1999) reported that mosaic in India is caused by the newly reported virus SCSMV, not by SCMV. However, detailed studies of Viswanathan et al. (2007) established the association of SCSMV and SCMV either alone or in combination. Based on molecular characterization of SCSMV genome a new genus name ‘Susmovirus’ was proposed (Viswanathan et al., 2008a) which was later established as Poacevirus genus in the family Potyviridae. Symptom of mosaic may vary in intensity with cultivar, growing conditions, temperature and strains of the virus (Viswanathan and Padmanaban, 2008). Detailed studies on the associated viruses with sugarcane mosaic very clearly established that SCSMV is more frequently found under Indian conditions than SCMV (Viswanathan and Karuppaiah, 2010; Viswanathan et al., 2008a).

An assay for viruses plays an important role to prevent the disease during germplasm exchange and seed cane production. Many methods to overcome viral infection have become ineffective. Since last two decades, in-vitro meristerm tip culture is playing a significant role in solving the problems of viral infection in plants. This technique is applied successfully to a wide range of agricultural crops and horticultural plants to eliminate the viral infection. Owing to their modes of replication and mechanism of movement within the plants, some viruses can be effectively eliminated from infected plants. Liu et al. (1972) and Wagih et al. (1995) reported the successful elimination of Sugarcane mosaic virus and Fiji disease virus in sugarcane through apex culture. By employing apical meristem culture, virus free plants have been produced successfully in sugarcane (Visessuwan et al., 1999; Chatenet et al., 2001; Fitch et al., 2001; Snyman et al., 2011).

There is a need to establish a rapid, convenient and reliable method for the viral detection in sugarcane. Currently, serological and RT-PCR based techniques are used to detect the viruses associated with sugarcane germplasm, quarantine and other routine screening of the breeding stocks. Though RT-PCR based detection system is superior to its serological counter parts, it is not suitable for routine virus diagnosis for crop like sugarcane due to higher cost involved in it. Therefore, initial screening by serological techniques is advisable and for confirmation of the samples those are doubtful, negative and valuable materials may be screened by RT-PCR. Screening by serological techniques needs specific and quality antiserum which relies on the quality of purified virions or protein. Virus purification from host is tedious and very often host protein contamination along the virus reduce the specificity of the produced antiserum. Therefore, the development of recombinant

antiserum is desired in all serological tests which can be used in routine diagnosis of the target virus. This process replaces highly purified virus preparations. In this work, we have expressed SCSMV-coat protein (CP) in an expression vector (Viswanathan et al., 2011) and later purified the expressed protein and raised polyclonal antiserum in rabbit. Subsequently, specificity and sensitivity of the serum were assessed in ELISA and its efficiency was validated with 349 sugarcane samples.

Materials and methods

Expression of SCSMV coat protein in E. coli and purification of fusion protein

The SCSMV-coat protein (CP) gene from mosaic infected sugarcane cv. Co 86032 was cloned in pTZ57R/T using the primers SCSMV-F690 and SCSMV-R (Viswanathan et al., 2008a). Then the SCSMVcp gene was released by digesting the pTZ57R/T-SCSMVcp plasmid construct with BamHI and HindIII. Later, the released fragment was sub-cloned in to similarly digested expression vector pMAL-c2x downstream to the malE gene, which encodes maltose binding protein (NE biolabs). The resulted plasmid construct was designated as pMAL-c2x-SCSMVcp and confirmed the presence of SCSMVcp in the transformed colonies by colony PCR. After induction in the expression medium, the optimum cell density of 0.5-0.6 at OD600 was reached in 45 to 60 min at 37°C. The induction of expression study revealed that the fusion protein expression level increased after 1 hr and reached the maximum by 5 hr of post-induction with 1 mM IPTG. Subsequently, large scale experiment was carried out by growing cells in 1 liter of LB with IPTG induction and the cells were harvested after 5 hr. The MBP-SCSMVcp fusion protein was purified using amylose resin and eluted in four fractions, of which maximum protein was eluted in the first two fractions. Separation of purified fusion protein in 12% SDS-PAGE and subsequent Western blot with anti-MBP antiserum confirmed the authenticity of the expressed protein. Separation of ~73 kDa indicated the induction of MBP-SCSMVcp fusion protein (MBP: ~43 kDa; SCSMVcp: ~30 kDa). Further the presence of the SCSMVcp in the fusion protein was confirmed by Factor Xa cleavage. About 5 mg of MBP-SCSMVcp fusion protein was purified from 1 liter of E. coli culture harbouring pMAL-c4x-SCSMVcp and polyclonal antiserum was produced in rabbit commercially from M/s Merck India, Bangalore.

Sugarcane samples used and ELISA assays

To assess serum titre, varying concentrations of the expressed protein 0.025, 0.5, 0.1, 0.3, 0.4, 0.5 and 1 µg were tested against antiserum dilutions of 1:10,000, 1:20,000, 1:30,000 and , 1:40,000 in DAC-ELISA. Similarly, to assess serum titre against viral antigen from host plant, dilutions of 1:2, 1:4, 1:32, 1:128, 1:512, 1:1024 and 1:2048 in carbonate buffer (15mM sodium carbonate, 35mM sodium bicarbonate, 0.02% sodium azide, Polyvinyl Pyrolindone – 0.5g, pH 9.6) were tested against 1:1000, 1:2000, 1:4000, 1:8000, 1:16,000 and 1:40,000 of antiserum. Leaf samples from virus free sugarcane cv Co 86032 served as a control. Various steps followed in DAC-ELISA are same as in the subsequent plant sample assays.



A total of 349 leaf samples varying in disease symptoms (Figure 1) were collected from different varietal collections maintained at Sugarcane Breeding Institute (SBI), Coimbatore, India. The samples were ground in pre-chilled mortar and pestle at a dilution of 1:10 W/V in carbonate buffer (15mM sodium carbonate, 35mM sodium bicarbonate, 0.02% sodium azide, Polyvinyl Pyrolindone – 0.5g, pH 9.6). The leaf extracts were then centrifuged at 10,000 rpm for 10 min at 4˚C and the supernatants were stored at -80˚C until use.

The crude extracts collected by the above method from different varieties of sugarcane served as an antigen in the experiment. The polystyrene plates were coated with 100μl leaf

extracts as triplicates and incubated for 2 hr. After incubation, 100 μl SCSMV-IgG of 1:2000 dilutions in conjugate buffer (100m of 1 × PBST, 0.2g albumin) was added as a primary antiserum. The tubes were then coated with 100µl of goat anti-rabbit IgG conjugated with alkaline phosphatase of 1:10,000 dilution in conjugate buffer (Sigma, USA) and incubated at 37°C for 2 hr at both the steps. Between each coating of antigen, antibody and conjugate, the plates were washed thrice with wash buffer (PBS-T for 5 min each) and tapped upside down on the blotting paper to remove the unbound materials. The final colour development was achieved by adding 100 µl of freshly prepared

enzyme substrate of 0.5 mg ml-1, p-nitro-phenylphosphate (Sigma, USA) and recorded the absorbance at 405 nm after 30 min in a micro plate reader (Spectra MAX 190, Molecular Devices, USA). The mean values greater than three times that of healthy control were considered as positive to the virus.

Results and discussion

The polyclonal antiserum produced against recombinant SCSMVcp detected the recombinant MBP-SCSMV-CP fusion protein upto 1:40,000 dilutions in DAC-ELISA. When sensitivity of the antiserum was checked using known concentrations of recombinant MBP-

Only T-L Irrigation Systems use strong, efficient, smooth running and reliable hydraulic power that growers use and work with every day. Water is distributed evenly across the crop, eliminating the “spoking” pattern common to the start-stop operation of electrically powered pivot systems, thus enhancing your production opportunities. The hydrostatic design also lowers maintenance costs and the likelihood of copper theft, and eliminates high voltage safety concerns. T-L pivot irrigation systems are easier on you, for a lifetime!

Let T-L show you how to get lasting value and decades of dependability from your irrigation investment. Contact T-L today to learn more.

HydrOSTaTICaLLyPOWered forcontinuous movement.

The T-L Difference

For more information, contact T-L Irrigation at (1) 402-462-4128 or email us at [email protected].

from your irrigation investment. Contact T-L today to learn more.

CERTIFIED

Q

U A LI T Y

ISO9001Proven Technology that Works!

The Choice is Simple | www.tlirr.com

TL-294K.indd 1 3/22/12 3:42 PM

Figure 1. Varying symptoms of mosaic / streak mosaic symptoms observed on different sugarcane varieties

a. severe b. moderate c. mild d. very mild e. asymptomatic

Diagnosis of Sugarcane streak mosaic virus using recombinant coat protein antiserum

in sugarcane


SCSMV-CP protein as antigen in ELISA, we found it is able to detect the antigen at concentrations as low as 2.5 ng (data not shown). In further assays, the detection efficiency of the antiserum against antigen from infected leaf extracts was found upto 1:10,000 dilution. However, antiserum dilution at 1:2000 was found optimum to detect SCSMV even in asymptomatic leaf samples and this dilution was used in all the subsequent assays. The optimum antigen dilution for crude leaf extract was found to be 1:10 (tissue: extraction buffer).

Subsequently the efficiency of the new antiserum was tested with 349 leaf samples collected from 332 sugarcane cultivars showing asymptomatic to varying degrees of mosaic/streak mosaic symptoms by DAC-ELISA. In this assay, 251 leaf samples were found to be positive. In the cases of leaf samples showing very mild, mild, moderate and severe mosaic symptoms in 52, 99, 19 and 26, respectively were positive in the assay (Table 1). Although range of absorbance values from different symptoms group looks similar, there was a gradual increase in maximum absorbance values from asymptomatic to severe symptoms. Severe mosaic samples had more than three times in mean absorbance values than that of asymptomatic ones and nearly two times of mild symptomatic samples. With increase in disease severity, there was also an increase in per cent detection of the virus in the samples. The studies also showed negative results in few mild and severe symptom groups. This may probably due to infection of SCMV in these samples. Our earlier studies also revealed that few sugarcane varieties have infection of SCMV alone (Viswanathan and Karuppaiah, 2010).

The recombinant SCSMVcp antiserum produced in the study efficiently detected the virus invariably from symptomatic to asymptomatic field samples even at 1:10000 antiserum dilutions. The validation of the antiserum with 349 field samples showing symptomless to different degrees of mosaic symptoms revealed that it detects SCSMV from 251 (72%) samples and of these positive samples, 50.5% of the samples were free from visual symptoms, even then the antiserum detected the virus from field samples which shows its efficiency. Earlier, this virus has been detected using DAC-ELISA, DAS-ELISA, DBIA and IC-RT-PCR (Hema et al., 2003a,b). Immuno-capture (IC)-RT-PCR was found more sensitive than ELISA which detects the virus from 66.7% of the samples failed to detect by ELISA and also using this technique,

both SCSMV and SCMV were detected from 16% of the samples (Reddy et al., 2011). Although these reports suggest production of antiserum against the virus earlier, for large scale virus-indexing of sugarcane samples at our institute we need higher quantities of serum with high titre. Hence we have taken up this work to produce recombinant antiserum against the virus. An increasing number of antibodies were prepared against the recombinant coat proteins that may be suitable for the detection by DAS-ELISA only in few cases (Vaira et al., 1996; Ling et al., 2000).

After establishing the associated viruses with sugarcane mosaic, detailed studies were conducted to develop molecular diagnostics to detect the viruses. Duplex-RT-PCR assay was standardized to detect SCSMV and SCMV in sugarcane (Viswanathan et al., 2008b) and subsequently multiplex-RT-PCR assay was standardized to detect important RNA viruses SCMV, SCSMV and Sugarcane yellow leaf virus (SCYLV) causing yellow leaf (Viswanathan et al., 2010). These assays are routinely followed at the institute to screen tissue culture derived sugarcane seedlings for the major viruses. We found that although molecular technique like RT-PCR are more sensitive than ELISA, they cannot be used for routine diagnostics/large scale screening against the viral pathogens and also cost of testing procedure has to be considered while adopting RT-PCR.

Viral diseases especially mosaic and yellow leaf seriously affect productivity in elite sugarcane varieties in India (Viswanathan and Balamuralikrishnan, 2005; Viswanathan and Rao, 2011). Systemic accumulation of these viruses gradually reduces the varietal performance over the years in the field. Since sugarcane is propagated through vegetative cuttings, the planting materials harbor virus inoculum and through the cropping generations from plant crop to ratoons, virus titre builds up and seriously impacting crop growth and productivity. To manage viral diseases in sugarcane clean seed programme is suggested with virus-free mother plants. Hence virus indexing has become mandatory and we need to develop a robust diagnostic technique like ELISA to handle more number of samples.

Sugarcane Breeding Institute, Coimbatore, India is the house of largest sugarcane germplasm collections in the world, maintains more than 3500 germplasm collections of Saccharum spp., related genera and hybrids at Kannur, Kerala as part of the World Sugarcane

Table 1. Detection of Sugarcane streak mosaic virus in sugarcane cultivars showing varying degrees of mosaic symptoms by DAC-ELISA using recombinant SCSMVcp antiserum

Degree of mosaic symptoms observed

No. of samples

Reaction in DAC-ELISA

Positive Negative

Absorbance at 405 nm

Mean absorbance

No. of samples

Per cent Absorbance at 405 nm

Mean absorbance

No. of samples

Per cent

No symptoms 109 0.123-1.326 0.321 55 50.5 0.017-0.117 0.067 54 49.5

Very mild 74 0.123-1.423 0.359 52 70.3 0.032-0.116 0.082 22 29.7

Mild 119 0.124-1.555 0.516 99 83.2 0.017-0.116 0.074 20 16.8

Moderate 19 0.204-1.658 0.856 19 100 - - - -

Severe 28 0.124-2.039 1.016 26 92.9 0.117-0.118 0.118 2 7.1

Total 349 251 71.9 98

For each sample minimum of three wells were loaded in microtitre plates.



Germplasm Collections. Apart from that we also maintain more than 3000 varieties / parent clones for breeding activities at Coimbatore. Also, the country is the second largest sugarcane growing country with diverse varieties under cultivation in both tropical and subtropical conditions. SCSMVcp polyclonal antiserum produced in this study will play a crucial role in SCSMV detection as is the most widely prevalent virus among the sugarcane cultivars/genotypes (Viswanathan and Karuppaiah, 2010) and in most of the sugarcane growing Asian countries. Following this success, polyclonal antisera were also produced against recombinant SCMVcp and SCYLVcp fusion proteins separately (Viswanathan, unpublished) and their standardization and validation would further strengthen sugarcane quarantine and virus indexing at the institute. Since few symptomatic plants were negative in ELISA, further studies are in progress to develop IC-RT-PCR to detect both SCSMV and SCMV together for sensitive detection of mosaic associated viruses in sugarcane. Ideally this procedure will be taken up after ELISA, to validate virus negative samples.

Conclusion

Although IC-RT-PCR and RT-PCR are more sensitive than ELISA, they cannot be used for routine diagnostics/large scale screening against various viral pathogens and also cost of the testing procedure is prohibitive. We suggest that ELISA can be used for large scale screening of sugarcane viruses and the other PCR based sensitive techniques may be used to screen those samples which are found doubtful and negative in ELISA, besides for valuable samples of international importance.

Acknowledgements

Authors are thankful to Dr. N. Vijayan Nair, Director of the Institute for the support and encouragement. Financial support received from DBT, New Delhi under NCS-TCP is gratefully acknowledged.

References

Agnihotri, V.P. (1996) Current sugarcane disease scenario and management strategies. Indian Phytopathology 49: 109–126.

Balamuralikrishnan, M., Doraisamy, S., Ganapathy, T. and Viswanathan, R. (2004) Comparison of antibody- and genome-based diagnostic techniques for Sugarcane mosaic virus in sugarcane. Phytoparasitica 32: 52-56.

Barber, C.A. (1921) The mosaic mottling disease of the sugarcane. International Sugar Journal 23: 12-19.

Chatenet, M., Delage, C., Ripolles, M., Irey, M., Lockhart, B.E.L. and Rott, P. (2001) Detection of Sugarcane yellow leaf virus in quarantine and production of virus-free sugarcane by apical meristem culture. Plant Disease 85: 1177-1180.

Fitch, M.M.M., Lehrer, A.T., Komor, E. and Moore, P.H. (2001) Elimination of Sugarcane yellow leaf virus from infected sugarcane plants by meristem tip culture visualized by tissue blot immunoassay. Plant Pathology 50: 676-680.

Grisham, M. P. (2000) Mosaic: 249-254 (In: Rott, P., Bailey, R.A., Comstock, J.C., Croft, B.J. and Saumtally, A.S. (Eds)). A Guide to Sugarcane Diseases. CIRAD/ISSCT, Montpellier, France.

Hall, J.S., Adams, B., Parsons, T.J., French, R., Lane, L.C. and Jensen, S.G. (1998) Molecular cloning, sequencing and phylogenetic relationship of a new potyvirus: SCSMV and a reevaluation of the classification of the Potyviridae. Molecular Phylogenetics and Evolution 10: 323-332.

Hema, M., Joseph, J., Gopinath, K., Sreenivasulu, P. and Savithri, H.S. (1999) Molecular characterization and interviral relationships of a flexuous filamentous virus causing mosaic disease of sugarcane (Saccharum officinarum L.) in India. Archives of Virology 144: 479-490.

Hema, M., Kirthi, N., Sreenivasulu, P. and Savithri, H.S. (2003a) Development of recombinant coat protein antibody based IC-RT-PCR for detection and discrimination of Sugarcane streak mosaic virus isolates from Southern India. Archives of Virology 148: 1185–1193.

Hema, M., Kirthi, N., Sreenivasulu, P. and Savithri, H.S. (2003b) Comparison of direct binding polymerase chain reaction (DB-PCR) with recombinant coat protein antibody based DBIA and IC-RT-PCR for the detection of Sugarcane streak mosaic virus causing mosaic disease of sugarcane in India. Current Science 85: 1774.

Koike, H. and Gillaspie, A.G. (1989) Mosaic: 301-322 (In: Ricaud, C., Egan, B.T., Gillaspie, A.G., and Hughes, C.G. (eds)). Diseases of Sugarcane- Major Diseases. Elsevier, Amsterdam.

Liu, L.S. (1972) Freeing sugarcane from mosaic virus by apical meristem and tissue culture. Taiwan Sugar Experiment Station Report 57: 57-63.

Ling, K.S., Zhu, H.Y., Jiang, Z.Y. and Gonsalves, D. (2000) Effective application of DAS-ELISA for detection of grapevine leaf roll associated closterovirus-3 using a polyclonal antiserum developed from recombinant coat protein. European Journal of Plant Pathology 106: 301–309.

Reddy, Ch.V., Sreeivasulu, P. and Sekhar, G. (2011) Duplex-immunocapture-RT-PCR for detection and discrimination of two distinct potyviruses naturally infecting sugarcane (Saccharum spp. hybrid). Indian Journal of Experimental Biology 49: 68-73.

Snyman, S.J., Meyer, G.M., Koch, A.C., Banasiak, M. and Wat, M.P. (2011) Applications of in- vitro culture systems for commercial sugarcane production and improvement. In-vitro Cellular Development Biology 47: 234-149.

Vaira, A.M., Vecchiati, M., Masenga, V. and Accotto, G.P. (1996) A polyclonal antiserum against a recombinant viral protein combines specificity with versatility. Journal of Virological Methods 56: 209–219

Visessuwan, R., Chiemsombat, P., Naritoom, K. and Surijachaijakorn, M. (1999) Role of growth regulators in meristem culture and production of virus free sugarcane germplasm. Sugar Tech. 1: 82-88.

Viswanathan, R. and Balamuralikrishnan, M. (2005) Impact of mosaic infection on growth and yield of sugarcane. Sugar Tech. 7: 61-65.

Viswanathan, R., Balamuralikrishnan, M. and Karuppaiah, R. (2007) Sugarcane mosaic in India: A cause of combined infection of Sugarcane mosaic virus and Sugarcane streak mosaic virus. Sugar Cane International 25: 6-14.

Viswanathan, R., Balamuralikrishnan, M. and Karuppaiah, R. (2008a) Characterization and genetic diversity of Sugarcane streak mosaic virus causing mosaic in sugarcane. Virus Genes 36: 553-564.

Viswanathan, R., Balamuralikrishnan, M. and Karuppaiah, R. (2008b) Duplex reverse transcription polymerase chain reaction (D-RT-PCR) a technique for simultaneous detection of viruses causing sugarcane mosaic. Sugar Tech. 10: 81-86.

Viswanathan, R. and Karuppaiah, R. (2010) Distribution pattern of RNA viruses causing mosaic symptoms and yellow leaf in Indian sugarcane varieties. Sugar Cane International 28(5): 202-205.

Viswanathan R., Karuppaiah, R., Balamuralikrishnan, M. (2010) Detection of three major RNA viruses infecting sugarcane by multiplex reverse transcription-polymerase chain reaction multiplex-RT-PCR. Australasian Plant Pathology 39: 79-84.

Viswanathan, R., Karuppaiah, R., Ganesh Kumar, V. (2011) Expression of Sugarcane streak mosaic virus (SCSMV) coat protein in expression vector as a fusion protein with maltose binding protein. Journal of Sugarcane Research 1: 63-68.

Viswanathan, R. and Padmanaban, P. (2008) Hand Book on Sugarcane Diseases and their Management. Sugarcane Breeding Institute, Indian Council of Agricultural Research, Coimbatore, India.

Viswanathan, R. and Rao, G.P. (2011) Disease scenario and management of major sugarcane diseases in India. Sugar Tech. 13: 336-353.

Wagih, M.E., Gordon, G.H., Ryan, C.C. and Adkins, S.W. (1995) Development of an axillary bud culture technique for Fiji disease virus elimination in sugar cane. Australian Journal of Botany 43: 135-143.

Diagnosis of Sugarcane streak mosaic virus using recombinant coat protein antiserum

in sugarcane


Dock and port areas the world over hold a fascination that few other industrial facilities can match. While the movement of containers and TEU’s may appear chaotic to the casual observer, every container can usually be identified and, more to the point, has a destination. But despite the fact that - with a few variations on the theme - ports all work in much the same way and provide a similar service, they all have their own particular characteristics or DNA.

Many of the established West African ports offer containerisation and bulk cargo handling facilities and, of course, bulk cargo’s by definition need a completely different method of handling. Even though a number of companies are active in the handling of bulk cargoes, Stockport based, FPE Global is fast developing a significant reputation for dock based sugar handling systems.

When one of the largest of the West African refineries caught fire in July 2012 the consequences could have been extremely severe; not just for the company but the region as a whole. Fortunately the refinery was still able to work at around 35% capacity and there

were significant sugar stockpiles. The stockpiles though, were not inex-haustible, which meant that there was a genuine urgency to get the refinery back to full production as soon as possible.

Due to the quick response of the refinery staff and local fire fighters the damage was restricted to the bagging sugar storage room and the sugar handling hall. The refinery, including melters, centrifuges, dryers and screens was largely un-affected as was the packing hall. Some while ago,

FPE Global installed two additional conveying lines in a new extension. As these two lines escaped fire damage, it was still possible to refine 1,500 tonnes of sugar per day while rebuilding took place.

FPE Global has developed long standing relationships with all the sugar refiners at this port and within seventy two hours of the fire being extinguished, a team of seven engineers were on site. The priority at this stage was a comprehensive damage assessment covering the mechanical handling equipment and the electrical control systems. From this assessment, a budget was prepared that would be presented to the client. While the site team was able to help with clearing of damaged machinery, the opportunity was taken in conjunction with senior on-site engineers, to completely review the way that the existing system had been designed. It soon became apparent that with a few revisions to the work area it would be possible to not only provide a more pleasant environment for the work force but also be able to increase the capacity should that ever be required - all within the budget. The target date to complete the entire project was set at 16th December 2012.

PRODUCT FEATURE

www.internationalsugarjournal.comFPE Global wins fire damaged sugar system replacement contract

www.fpeglobal.com

Part of the processing system

Screw conveyors


Because of the damage caused by the fire, the entire sugar handling hall had to be stripped out, cleared and cleaned. The electrical system was too badly damaged to be saved but before the total rewire could start, all the structural steelwork had to be manufactured and installed.

Back in the UK, work on the project was started the moment that FPE Global was awarded the contract. Engineers at FPE Global have extensive experience of this type of system; where the need for reliable, 24 hour operation coupled with ease of maintenance is of paramount importance. So once the client had confirmed the proposal, work began on system manufacture. The mechanical handling system consisted of twelve screw conveyors of varying lengths and rated at 160 tonnes per hour, three bucket elevators rated at

200 tonnes per hour, three 80 tonne fin-ished product silo’s, a huge range of discharge valves - both manual and automatic - together with chutes and ducting.

The electrical systems including the Motor Control Centre and control panels were all supplied by FPE Global and installed by the on-site maintenance teams with FPE Global’s help and supervision. Also, in order to save time, as much of the structural steelwork - which was designed by FPE Global - was contracted out to local fabricators who worked with engineers from FPE Global.

Every item manufactured by or supplied by FPE Global was air freighted to save time.

Chris Bailey, the Managing Director of

FPE Global, spent a total of twelve days on site leading the survey and fine tuning the quotation. He said: “Looking at film of the fire, it’s amazing that there was no loss of life and that firefighters were able to restrict the damage. As far as we were concerned though, the key to this project was our ability to react quickly. Within three days of the fire we had a team of seven on site work-ing eighteen hour days. Back in the UK, design office and factory staff worked flat out. Other than the Christmas break we have had staff on site since July 2012. Consequently, everyone involved is quietly proud of what we have all been able to achieve.”

Screw conveyor feeding a bucket elevator

“As far as we were concerned

though, the key to this project was

our ability to react quickly. Within

3 days of the fire we had a team of 7 on site working 18 hour days… Consequently,

everyone involved is quietly proud of what we have

all been able to achieve”

Chris Bailey, Managing Director, FPE Global

For further information contact: Chris Bailey at FPE Global

on +44 (0)161 477 4775

PRODUCT FEATURE: FPE Global wins fire damaged sugar system replacement contract


Statec Binder has recently introduced a newly developed bag closing system for woven PP (polypropylene) bags, with or without PE (polyethylene) inner liner (Figure 1). Effectively, after the bag top has been trimmed, woven PP tape is applied to provide reliable closure without the need for sewing.

PP bags are used in the sugar industry. Statec Binders system accommodates bags produced from multiwall paper, paper, polyethylene/plastic and polylined paper.

Where requested an optional sewing head can be included, resulting in bag

top trimming, followed by bag stitching, followed by the tape over seal (Figure 2). This solution ensures secure, sift-proof bag closure and is expected to appeal especially to Asian customers handling dusty materials and food products, including pet foods.

The inner liner is heat sealed or stitched together with the outer bag and overtape above the seal. The tape is applied over the top and both sides of the bag resulting in a sealed closure that is always strong, clean, durable and siftproof.

Pedestal-mounted, the compact tape over seal features a strategically positioned control panel for easy readability. Additional features include a variable speed drive, digital temperature control, adjustable operating height and an emergency stop system.

NEW PRODUCTS FOCUS

www.internationalsugarjournal.comsugarJOURNALwww.internationalsugarjournal.com

INTERNATIONAL

Figure 2. Optional bag stitching plus tape over seal

Figure 1. Statec Binder’s bag closing system for woven polypropylene bags

New bag closing system from Statec Binder

For further information contact: Gerhard Steinmayr

Email: [email protected] Tel: +43 3112 385 804 www.statec-binder


Anton Paar introduces a rheometry revolution: MCR 702 with modular TwinDriveTM technology (Figure 1). This is the only available rheometer to cover all possible rheological applica-tions - with an accuracy of 1 nNm and features like the IsoLign Piezo flange, offering measuring gap control down to an unprecedented size of 10 nm.

Anton Paar’s TwinDriveTM technology combines two powerful synchronous EC (Electrically Commutated) motor units in a modular setup: The upper EC motor in the rheometer is permanent, the lower EC motor can be extracted and integrated at will. Due to the EC motors’ renowned dynamism and precision, users have multiple options

of how to employ these units, opening up entirely new rheological applications.

MCR 702 TwinDriveTM is claimed to be the first rheometer to precisely cover all rheological applications -

past, present and future.

Figure 1. Anton Paar’s MCR 702 with modular TwinDriveTM technologyAnton Paar introduces rheometer with TwinDriveTM technology

For further information contact: Email: [email protected]

www.anton-paar.com

New products focus


16-18 April 2013Australian Society of Sugar Cane Technologists Conference - Townsville, AustraliaContact: ASSCT Secretariat Tel: +61 7 4954 3956 Email: [email protected] www.assct.com.au

5-8 May 20133rd European Society of Sugar Technology Conference - Warsaw, PolandContact: Dr. Jürgen Bruhns Tel: +49 30 803 5678 Email: [email protected] www.esst-sugar.org

12-15 May 2013Sugar Industry Technologists Inc. Annual Conference - Guangzhou, ChinaContact: Edgar Aguirre Tel: +1 863 983 3637 Email: [email protected] www.sucrose.com/sit

15 May 2013VII ISO Datagro Sugar & Ethanol Conference - New York, USATel: +55 11 4191 6994 Email: [email protected] www.datagroconferences.com.br/emkt/ny2013_ 20130311_en_email.htm

23-24 May 2013World Biofuels 2013 - Seville, SpainTel: +44 20 3377 3658 Email: [email protected] www.worldbiofuels.agraevents.com

28-29 May 2013Sugar Asia - 5th International Exhibition & Conference on Sugar, Ethanol, Distilleries, Energy and Farming of Beet & Cane - Bangkok, ThailandContact: Nexgen Exhibitions Private Ltd Tel: +91 11 4153 6990/6583 8058 Fax: +91 11 4153 6991 Email: [email protected] www.nexgengroup.in/sugarasia

12-14 June 2013Annual Joint Meeting of the American Society of Sugar Cane Technologists - Panama City, Florida, USAContact: Freddie Martin Tel: +1 225 578 6930 Fax: +1 225 578 1403 Email: [email protected] www.assct.org

24-27 June 201328th International Society of Sugar Cane Technologists Congress - Sao Paulo, Brazilwww.issct2013.com.br/en/Home/

2-7 August 201330th American Sugar Alliance International Sweetener Symposium - Napa, California, USAContact: Vickie Myers Tel: + 1 703 351 5055 Fax: +1 703 351 6698 Email: [email protected] www.sugaralliance.org

14-18 October 2013XII International Congress on Sugar and Sugarcane Derivatives DIVERSIFICATION 2013 - Havana, CubaEmail: [email protected]

Bosch Rexroth Mellansel AB Cover II

Continental Profiles Ltd 255

De Smet Engineers & Contractors 237

FPE Global Ltd Cover I

International Sugar Journal Subscriptions Cover III

ISSCT Conference 2013 233

Iteca Socadei SAS 239

Praj Industries Ltd 243

proMtec Theisen GmbH 249

Siemens AG Cover IV

SKIL - Sugar Knowledge International Ltd 241

Statec Binder GmbH 245

StuvEx Safety Systems Ltd 247

Sugar Asia Conference 2013 287

T&L Process Technology 235

T-L Irrigation Co 281

Index of advertisers

Meetings Calendar For the latest updates visit: www.internationalsugarjournal.com

In need of reliable system solutions that allow you to focus on your core business? Rexroth – your one stop shop for excellent drive and control solutions that maximize performance and help optimize productivity. Regardless of technology or location our global organization can provide you with the right solution to meet the challenging everyday demands of the sugar industry. You can focus on your core business, relying on our high quality solutions and global network to provide complete peace of mind.

Bosch Rexroth AG www.boschrexroth.com/sugar

Photo by courtesy of Hägglunds.

BR_ISJ_Outlook_2013.indd 1 2012-11-13 10:06

Not currently an ISJ subscriber?

The complete value chain from sugarcane and beet production right through to sugar processing and sugar refining PLUS the latest developments in the biofuelsand biobased sectors

How you will benefi t from an ISJ subscription:• The latest in-depth news, analysis and intelligence from your

industry in one place • Reliable information that could improve your efficiency and save

your company money • React quickest with the latest issue available online at


The World’s Leading Sugar Industry Magazine• Cane sugar manufacturing • Beet sugar manufacturing • Sugar refining • Equipment and machinery • Alternative sweeteners • Biofuels • Cogeneration

• Nutrition and health

• Environmental issues

• Food and non-food uses of sugar

• By-products - molasses, alcohol and vinasse

• Economics, trade and legislation

From time to time we may wish to send you information and offers about Informa plc products and services. If you do not wish to receive this information, please tick the following box. In some circumstances we may wish to pass on your details to carefully selected 3rd parties, in order for them to send you relevant information and offers. If you would like us to pass on your details in this way, please tick the following box. Data Protection: Personal Data supplied is subject to the Data Protection Act 1998. The personal information shown on this form, and/or provided by you, will be held on a database and may be shared with companies in the Informa Group in the UK and internationally. It may be used to keep you, or any additional names provided by you, up to date with developments in your industry. If you have any questions about Informa’s use of your data please write to the Database Manager, PO Box 461, West Byfl eet, KT14 9BN. Tel: +44 (0)20 7017 5239 Fax: +44 (0) 20 7017 6241 or email [email protected]

International Sugar Journal one year sub:UK £600 Europe €750 Rest of World US$955

To enquire about advertising in ISJ, please contact [email protected]

or call +44 (20) 701 77559

3 easy ways to subscribe...1. To order online, please visit

https://store.agra-net.com/isj.html2. Call Alex Cast on +44 (20) 7017 750673. Or email [email protected]

for a FREE sample copy


1010_TW_ISJ Subs ad update.indd 1 21/03/2013 07:52

Answers for industry.

siemens.com/sugargearunits

Reliable power providersFLENDER drive systems for more productivity and efficiencyin the sugar industryE2

0001

-F37

0-P9

00-X

-760

0

The manufacture of sugar involvesa great expense of energy. Production calls for, above all, operational reliability and problemfree processes. FLENDER® drive systems are extremely reliable and combine productivity with energy effi-ciency.

Convey, transport, extract, press

A system’s productivity depends on the power of its drive components and on their coordination and control. Our decades of experience and our ex-pertise in drive trains are the best basis for optimum system solutions.

FLENDER drives for the sugar industry

For the mill drive you will find in the newly developed planetary gear units and the load-sharing FLENDERDUORED 2® optimised industry solutions. Type PLANUREX® slow-running planetary gear units are used as diffusor drives and in cane presses. Frequency-controlled FLENDER gear units are often also usedin countercurrent cossette mixers.

Wherever you use our solutions, our know-how will be your decisive com-petitive advantage.

FLENDER gear unit

DUORED 2

PLANUREX planetary-gear unit

E20001-F370-P900-X-7600_EN_sugar.indd 1 26.03.13 15:42

international sugar - inicio · international sugar journal 2013, vol. 115, no. 1372 229 for the...

Documents