opwall - an - report - 2009 v9 - printable
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Report on a Proposal to Manufacture Semi-refined Carrageenan (PES E407a) on
Pulau Kaledupa, SE Sulawesi, Indonesia
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Report on a Proposal to Manufacture Semi-refined Carrageenan (PES E407a) on
Pulau Kaledupa, SE Sulawesi, Indonesia
Contents:
Introduction Page 3 - 4
Background Page 5 - 8
Quantitative Aspects of the Process Page 9 - 44
Business Model Page 45 - 65
Summary Page 66 - 68
References Page 69 - 72
Appendix 1 Description of Manufacture Page 73 78
Appendix 2 Correspondence with Regulators Page 79 - 83
Appendix 3 Commodity Prices Page 84 - 85
Appendix 4 Fertiliser Calculations Page 86 - 89
Appendix 5 Methodology Page 90
Prepared by:
Piotr Kalinowski
Oaklea Ltd
June 2009
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Introduction
In November 2007 we produced a report A proposal to increase the value of farmed seaweed in
Kaledupa, SE Sulawesi, Indonesia which suggested that the development of a carrageenan
processing plant on Kaledupa would have the potential to double the annual income for 600
fishers who also have seaweed farms in the Kaledupa area.
Participation in the scheme would be tied to surrender of fishing licences so that it provides an
alternative income for those coming out of the fishery. This proposal could provide the
mechanism to enable the Kaledupa reef fishery to recover - so Maximum Sustainable Yields
could be achieved for the remaining fishers, rather than the current significantly depressed catch
rates.
As a result we were asked by the Operation Wallacea Trust, as part of the Darwin Initiative
(Project Ref.No: 162/16/002 Building Capacity for sustainable fisheries management in the
Wallacea region), to further provide additional information on the quantitative chemistry of the
process and to create a comprehensive business plan that would give sufficient confidence for
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securing financial support from government (eg. the Wakatobi Regency and COREMAP) andfrom business sectors. Successful implementation of a project such as this could have significant
benefits for other coastal communities by providing value-added income from their seaweed
production.
This report therefore intends to provide a Proof of Concept - a milestone on the way to a fully
functioning prototype - that could then be rolled out into the wider Indonesian seaweed-growing
communities.
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Background
Kappa Carrageenan is a hydrocolloid found in Kappaphycus alvarezii, the commonest tropical
farmed seaweed and the dominant farmed species on Kaledupa. When transformed by alkali
treatment into Processed Eucheuma Seaweed E407a (PES) or Semi Refined Carrageenan
(SRC)) it has a great variety of uses in the food and petfood industries because of its ability to
make gels and as a thickener in prepared foods.
New uses are constantly being discovered. A current search through United States Patents
reveals 12,491 patents issued containing the term carrageenan or one of its several variants.Only a few are for its initial manufacture from seaweed. The vast majority are for an improvement
or modification of its properties or for its incorporation into a multitude of food, petfood or non-
food (e.g. toothpaste) formulas or recipes.
From its first beginnings in the late 1960s in the Philippines to 1990, world production rose from
zero to about 67,000 MT/annum (MT = metric ton) of dried seaweed. About 50,000 MT was from
the Philippines and 14,500 MT from Indonesia(1)
.
By 2001 world production had risen to 110,000 MT/annum and in 2005 expanded to 150,000-
200,000 MT/annum, resulting in an estimated 100m USD/annum farmgate income to many tens
of thousands of farmers(2)
.
By 2007 the estimated production in Indonesia was matching the Philippines at about 85,000
MT/annum each. However, the significant difference between these two countries was that in the
Philippines about 86% of the dried crop had undergone value-added processing whereas in
Indonesia the figure was nearer 23%(2)
.
Much of Indonesias burgeoning production of dried seaweed was and is currently exported to the
Philippines, where there are 16 large processing factories(3)
.
However, this may well change if the Indonesian Government fulfills its declared aim to stop
exports of dried seaweed. Dr Martani Huseini, Director-General of Marine Processing and
Marketing, Indonesia Ministry of Maritime (Marine) Affairs and Fisheries has been quoted "It's
definite, we're putting a stop soon to the exports of dried seaweed as soon as we're ready with
our own carrageenan processing plants."(3)
.
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Indonesia has ambitious targets to be the main world supplier of tropical seaweed by 2012. In a
keynote speech at the Seaweed International Business Forum and Exhibition in 2008, Fishery
and Maritime Affairs Minister, Freddy Numberi, said he was optimistic seaweed could be
developed further in the future and reap a large profit, alleviate poverty and improve people's
well-being. He said local administrations should issue ordinances that regulated areas allocated
for cultivation and provide capital assistance. "The central government will assist in counseling,
training and process technology, while we count on local administrations for the rest," said
Minister Numberi. South Sulawesi Governor Syahrul Limpo said that as the biggest producer of
seaweed in the country, the province would continue to develop the plant not only in production
and quality, but also in establishing processing facilities so it would have added value(4)
.
The General Chairman of the Indonesian Seaweed Association, Jana Anggadiredja said that
Indonesia had become the world's biggest seaweed raw material producer for the Eucheuma
species type (i.e. including K.alvarezii). According to him, Indonesia is expected to become the
world's biggest seaweed producer and leading nation in the seaweed industry in 2010(5)
.
The worlds biggest carrageenan importer is North America which imports around 53 percent,
combining the annual consumption of both Canada and the United States, according to the Food
and Agriculture Organisation (FAO). Other big importers of carrageenan include Europe - 24
percent, Latin America - 10 percent, Australia - 8 percent and Japan - 5 percent. The EuropeanUnion alone needs about 1,500 metric tons monthly, FAO data show
(3).However, caution should
be exercised when assessing such statistics. Up-to-date, reliable and official statistics for
seaweed and processed carrageenan production are notoriously hard to find(6) (7)
. For example,
the above data does not include China or India!
Even if the absolute accuracy of such production statistics is in doubt, what is certain is that the
world demand for seaweed products such as carrageenan is inexorably rising. Not only are new
uses being found for the product in developed countries but the existing usage is constantly
increasing as a result of globalisation and rising income levels, especially in the BRIC countries(Brazil, Russia, India & China). This is because hydrocolloids are fundamental, albeit minor,
components of a large variety of processed foods and toiletries.
Until recently the farmgate price for dried seaweed was relatively steady, showing slight highs
and lows in what was a generally rising trend. However, in early 2008 the seaweed market
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started soaring. The price for Indonesian seaweed more than tripled, from about IDR 5,000 to as
much as IDR 18,000 (USD 1.80) per kilogram(8)
.
Then, almost as quickly, the seaweed bubble burst, adding this commodity to the list of the
world's assets such as stocks and shares, oil and houses that fell in value. By October 2008, it
was down to IDR 10,000/Kg. This crash was well forecast as early as April 2008(9)
.
The current price for dried seaweed (ex-Kaledupa - May 2009) is, once again, about IDR
5,000/kg(10)
.
One explanation for the jump in prices is that traders were responding to rising demand from
China, with its boost from the Olympics, while supplies from some sources, especially the
Philippines, weren't available because of bad weather. Another theory is that Chinese food-
ingredient companies were engaged in a trade war, with some colluding to drive up the cost of
seaweed in order to knock competitors out of the business. A yet further view is that speculators
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and traders saw the mid-year surge in crude oil and other commodity prices and expected
seaweed would follow, filling their warehouses in the hope that prices would keep climbing(8)
.
Some farmers and traders may have made matters worse by adulterating raw seaweed with sand
or cement to increase the product's weight, and hence its selling price, upsetting buyers in China
and sending prices into a downward spiral. These so-called trading-games have been a long-
term concern within the industry, undermining buyer-seller confidence(11)
.
Whatever the reason, or mixture of reasons, high prices resulted in farmers selling immature or
low-quality seaweed into the market, flooding buyers with too much supply at a time of world
recession.
This recent bubble and its subsequent bursting may possibly and beneficially result in all the
participants - growers, traders and factory buyers organising a more transparent market in the
future. For example, the Chairman of the Indonesian Seaweed Association, has recently been
pressing to create a certificate-of-origin program designed to force farmers to maintain minimum
quality standards(8)
.
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Quantitative Aspects of the Process
In our first report we summarised the conversion process of dried seaweed to PES (Processed
Eucheuma Seaweed) product as follows:
(a) Pre-rinsing carrageenan-containing seaweed to remove surface impurities and
contaminants
(b) Cooking the seaweed in a tank containing an aqueous solution of Potassium Hydroxide
(KOH) so as to cause desulphation at the 6-position of the galactose units of the
carrageenan, and so as to create recurring 3,6 anhydrous galactose polymers by
dehydration and reorientation
(c) Washing the seaweed in a neutralising bath of dilute Hydrochloric Acid
(d) Washing the seaweed in an optional bleaching step
(e) Rinsing the seaweed in water
(f) Drying and chopping the seaweed into chips or milling into powder
To these we have now also added further sections:
(g) Crane hoist and tank sizing
(h)Waste disposal
(i) Power, heat and fuel
(j) New versus second-hand
(k) Quality assurance and quality control
(l) Safety
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In this report we will attempt to quantify these stages, insofar as is reasonably possible and in the
light of laboratory experiments. These were undertaken using air-dried cottonii (i.e. K.alvarezii)
seaweed provided by Opwall Trust staff from local Kaledupan sources(12)
.
Note:
Important aspects and statistics are underlined.
It should be understood that, because of the scale effect, there is a measure of uncertainty when
applying laboratory findings to a pilot plant and especially to a full-sized plant.
The original general process description is re-shown as Appendix 1 - to allow for ease of
reference yet avoiding unnecessary repetition in this text.
(a) Pre-rinsing carrageenan-containing seaweed to remove surface impurities and
contaminants
Two samples of dried seaweed were sent for testing. They differed greatly in the amount of
impurities, or trash, present. The first contained considerable quantities of man-made debris,
mostly derived from the farming operation. This included plastic twine, used to tie the weed to thecarrier rope and, to a lesser extent, expanded foam pieces from the floats. It also contained an
amount of epiphytic algae. These plastic items, in particular, will fully resist subsequent chemical
treatment and still be present in the final chopping, drying and milling stages. It is anticipated that
such items may severely clog the chopping/milling machines or possibly even melt in the drier.
They will pose a serious threat to the quality of the finished carrageenan product. In sharp
contrast the second, later, batch was almost totally free of such trash items.
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The conclusion is that participating seaweed farmers and their staff (usually family members) will
need to be well-trained to carefully strip the mature weed fronds from the carrier rope to avoid
such contamination in the first place.
As a second step, at the factory site, after the initial receiving, weighing and sampling of dried
weed from growers, there should be a wide sorting stage in the form of a slow-moving belt
conveyor at waist height. It should have adequate staff present to pick out extraneous matter a
boring but necessary task. If done properly, any growers not fulfilling pre-determined qualitystandards will thus be quickly identified and should then be penalised by a proportionate fine,
deducted from their crop payment. These quality standards should also include moisture content
and sand contamination, to be measured by the quality-control laboratory that is envisaged on-
site. The ultimate sanction for persistent problem growers should be refusal to accept their crop.
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There may be times, perhaps because of seasonal variations, when some of the incoming raw
material needs to be stored. All such stored material should be tagged so as to identify the
grower, weight of crop and delivery date. Payment should be dependent on the growers previous
quality record. If subsequently the stored batch is found to be below standard then that person
should be notified and an appropriate deduction in payment be made from their next delivery.
It will be readily apparent that any attempt by growers to play the destructive trading-games
mentioned previously will be quickly caught out by such a comprehensive checking system. It is
to be hoped that the great majority of member growers will see that such selfish actions are totally
counter-productive to the aims of the co-operative and not engage in them from the outset.
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It would be expected that the moisture content of the incoming seaweed would be about 35% -
38%, the industry norm. If a batch appears excessively wet then this should be confirmed by
moisture content measurement in the quality-control laboratory. Again, as with contaminants, thegrower should be penalised by a proportionate fine deducted from their crop payment. However,
mutatis mutandis, growers should also be rewarded for delivering crop that is drier than the norm
after all, they are, in effect, taking a lower price otherwise.
Unlike the (wholly avoidable) allowing of debris to remain in delivered seaweed or the (deliberate)
introduction of contaminants, the presence of excessive moisture content can be an unavoidable
and universal problem at certain times of year i.e. during the monsoon period. It is envisaged thatquality standards would allow for a general derogation in such circumstances.
Whilst every practical step should be taken by the growers to minimise contamination of the
seaweed by sand, some will inevitably be present. It must be removed to ensure that the acid-
insoluble ash content is at the low levels demanded by food regulations. The white crystals that
are present on the surface of the dried weed are of Potassium Chloride (KCl) and are of value at
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the next process stage and beyond. One possible solution (literally) is to hose down the crop as it
is taken to the next stage pre-using the make-up water required for that stage. The washings can
be allowed to settle in a small tank and the supernatant fluid (rinse-water), containing dissolvedKCl, may be drawn off and used in stage (b). The settled sand would be removed at appropriate
intervals.
(b) Cooking the seaweed in a tank containing an aqueous solution of Potassium Hydroxide
(KOH) so as to cause desulphation at the 6-position of the galactose units of the
carrageenan, and so as to create recurring 3,6 anhydrous galactose polymers by
dehydration and reorientation
The first report made a cautious assumption to design for a plant taking in 3,000 MT dried
seaweed/annum i.e. 600 farmers and half of the areas production.
A further assumption is that there will be 300 working days a year. This maximises the local
workforces (seaweed growers and factory staff) desire to earn an income yet fulfils their religious
and social requirements of a free day a week and for their other longer religious festivals and
holidays, such as Lebaran, which can take seven days in one block(10)
. It also allows an
additional few days for unexpected stoppages due, for example, to bad weather or mechanical
breakdowns.
Using these two factors the factory needs to process 10 MT/day of dried seaweed.
The process as described previously is a batch design, using a series of open-topped vessels
and the seaweed moved between them in a perforated basket. It will be shown later that the
seaweed requires to be heated in hot alkali solution for two hours or more and to be rinsed three
times for half an hour at a time.
Using these figures a further assumption is that each batch will take four hours. This allows half
an hour above the 3.5 hours minimum process time in order to load and unload and also lower
and lift the basket full of seaweed through its various stages.
A yet further assumption is that there will be three eight-hour shifts a day in order to maximise
throughput whilst reducing the size and maximising the use of high capital-value machinery.
There will therefore be six batches processed in a day, each of 1.66 MT of dried seaweed.
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The bulk density of reasonably compressed dried seaweed was found to be 250 g/litre, which
equates to 250 kg/m3.
Therefore the net tank volume needed to accommodate 1.66 MT is 6.64 m3 (1000/250 x 1.66)
The gross tank volume, allowing for a safe liquid level below the tank top, should be 7-7.5 m3,
dependent on the tank shape.
The seaweed at the end of this stage has increased in weight because of water-absorption. The
bulk density of wet compressed seaweed after processing with 5% aqueous KOH at 60C for two
hours was found to be 515 g/litre, equating to 515 kg/m3. Therefore the weight of the basket
contents at the end of this stage of the process will be 3.42 MT (6.64 x 0.515).
According to our extensive Patent searches and published references, some of which are quoted
in Appendix 1, a variety of strong alkalis (water-soluble bases) may be used to achieve the
chemical transformation step required. Thus not only Potassium Hydroxide (Caustic Potash -
KOH), but also Sodium Hydroxide (Caustic Soda - NaOH) and Calcium Oxide (Quicklime - CaO)
which transforms in water to Calcium Hydroxide (Slaked Lime Ca(OH)2) are commonly
mentioned.
Food-grade NaOH and CaO are very significantly less expensive than food-grade KOH. Currently
NaOH is 70% cheaper and CaO is 62.5% cheaper than KOH see Appendix 3.
However, careful examination of the European Union E407a specification for PES E407a
carrageenan reveals that it only mentions KOH.
Extract from Commission Directive 96/77/EC, amended as 2009/10/EC:
Definition: Processed eucheuma seaweed is obtained by aqueous alkaline (KOH) treatment of
the natural strains of seaweeds Eucheuma cottonii and Eucheuma spinosum, of the class
Rhodophyceae (red seaweeds) to remove impurities and by freshwater washing and drying to
obtain the product.
Accordingly, we asked the UK Food Standards Agency and the European Commission
Directorate-General for Health and Consumer Protection to interpret the definition see
correspondence in Appendix 2. They have adopted a narrow, if predictable, view that only KOH -
treated carrageenan may be used or sold within the EU. Whereas the important and authoritative
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FAO/WHO Codex Alimentarius simply mentions soaking the cleaned seaweed in alkali for a
short time and the USA Code of Federal Regulations is silent on the use of alkali. Thus these two
major alternative food-regulating bodies do not specify KOH as a process requirement in themanufacture of carrageenan.
Therefore, a less than straightforward situation exists, where in the great majority of world
markets, especially the USA, these other alkalis may be used - but for carrageenan destined for
the EU only KOH may be used.
The possibility of asking the European Commission to review and amend their Directive does
exist, but it is a prolonged and tedious route with an uncertain outcome.
For the purpose of this report the use of alternative alkalis is therefore acknowledged but not
explored much further.
Another factor needing consideration at this stage of the process is whether freshwater or
saltwater is to be used.
The argument for salt water is that it is almost a limitless resource. Against it is that disposal of
waste-water would have to be into the surrounding coastal water forming part of the Wakatobi
Marine National Park, famously rich in biodiversity. Whilst the quantities of waste released from
the process are likely to be minute in relation to the huge volume of ocean, it may create an
undesirable precedent.
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significantly amend its properties, particularly by the addition of gums such locust-bean gum - that
the precise strength of the alkali solution will also be equally infinitely variable. The staff operating
the plant will need to closely monitor the product, using the quality-control laboratory to constantlygive them feedback and then making appropriate adjustments in order to provide an optimal
product. Thus what is about to be recommended here is merely indicative, to give a basis to the
process. It is to be hoped that such future adjustments will allow for greater efficiencies in inputs
of both energy and chemicals.
Whilst several texts suggest the use of quite severe alkaline conditions, of the order of 8 12%
w/v, we suggest that 5% w/v is a good starting point. The laboratory gels made using this lower
concentration of alkali easily matched the gel strength of a commercial sample of Philippine food-
grade PES that was used as a benchmark. They far exceeded that same commercial sample inthe viscosity test, strongly suggesting that the commercial sample was made in chemically harsh
conditions(13)
.
Interestingly, when comparing KOH and CaO it was found that 5% KOH gels always made
stronger gels but the 5% CaO gels always had higher viscosities. This offers an opportunity to
use the process parameters to match the end-user requirements at least in non-EU countries,
where both alkalis are permitted.
One crucial feature of the process that must be fully understood is that the temperature (and to a
lesser extent time and dissolved salt concentration) settings are critical. The purpose is to allow
for the required chemical transformation to take place within the seaweed structure (gel or
heterogenous process) but not for the carrageenan to solubilise (sol or homogenous process).
Thus, at the end of this stage of the process the residual liquor (liquid produced during cooking), if
cooled to ambient temperature, should remain liquid. To ensure this the process temperature
must be kept in the 60-65C range. As the temperature nears or exceeds 70C then progressive
solubilisation will occur, leading to costly loss of PES product from the seaweed mass and the
possibility of rapid thickening of the liquor, giving rise to severe pumping problems, especially if
an external heat exchanger is used.
This stage of the process should take about two hours. Insufficient time may lead to incomplete
conversion and excessive time may render the process inefficient. Practical experience will lead
to more accurate timing.
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Our initial experiments used 150 g quantities of loosely packed seaweed, which required 1,500 ml
of alkali solution to fully cover the weed - a rather large ratio of 1:10 w/v. In order to reduce the
size of the process tanks to a minimum, we have found that this seaweed:liquid ratio can bedecreased to 1:3.6 w/v by using compressed seaweed. This is achieved by exploiting a particular
physical property of dried seaweed. When compressed for a short period the weed relaxes and
remains in its compressed shape, even after the original pressure has been removed. This
property is already advantageously used by growers and traders to compress the weed into
naked bales for shipment(11)
. Thus the process requires the seaweed to be strongly compressed
into the holding basket and for a lid to be secured to resist any swelling during the hot liquor
stage. No pre-chopping of the seaweed fronds is envisaged. Were it to take place then the bulk
density may beneficially increase further but at the possible cost of lowered porosity, leading to
poorer circulation of liquor.
In view of the seaweeds compressed state, the possibility of using mixing devices such as tank
propellers to circulate the liquor is compromised. The preferred solution would be to lift and lower
the basket several times during this cooking stage. This will allow for an even distribution of
liquor concentration and heat within the entire mass of seaweed material.
At the end of the heating process it was found that there was an about 30% reduction in volume
of liquor - that amount having been absorbed by the dried seaweed. Therefore this needs to be
replaced by fresh liquid. This will be sourced from the previous rinse step thus its volume will
need to be 2 m3 (6.64 m3 x 0.3). After this pre-use, the rinse-water, enhanced with dissolved KCl
from the seaweed, would be heated to the required temperature and treated with an appropriate
quantity of KOH to become the top-up liquid for this stage. This means that there is at least a
30% continuous refresh rate.
However, it remains to be seen if unexpected build-up of minor components leaching from the
seaweed interfere with the process and therefore require a higher refresh rate. As a precaution, it
is suggested that twice a day (i.e. after three heating cycles) the residual 4.65 m3 (6.64 m3 x 0.7)
of hot liquor is discarded and a fresh batch of 5% KOH liquid used. The daily 9.3 m3 (4.65 m3 x
2) of water required for this purpose can usefully come from the discarded counter-current wash
tank water with its existing low KOH content see section (c & e) below.
This will create a waste-stream of 9.3 m3 per day of
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ions thus the earlier requirement to conserve the KCl crystals present on the surface of the
dried seaweed if using alkalis other than KOH. The second step is dehydration, which utiliseshydroxide ions, thus reducing the alkalinity of the solution, whilst releasing sulphate ions from the
seaweed, producing soluble Potassium Sulphate, a useful fertiliser(14)
.
It is envisaged that this tank will be well insulated, to minimise heat losses. A further factor to
consider is whether to specify for the tank to be fitted with external heating coils using steam or
for the heat transfer to be carried out separately through a heat-exchanger using hot water a
slightly more complex solution. For safety reasons, it is suggested that a hot-water boiler is used,
rather than a steam boiler. However this choice does severely reduce heat-transfer rates because
pressurised steam has a much higher temperature e.g. at 30 bar pressure it boils at 234C and italso has three times more enthalpy (total heat) than water and so can be used very effectively in
the relatively small surface-area of heating coils on the side of the tank.
The hot-water boiler decision tips the balance in favour of using a large external heat-exchanger.
Importantly, it also allows for the possibility of utilising surplus heat from the electricity generator
on site. This energy-efficient use of combined heat and power (CHP) is discussed later.
(c & e) Washing the seaweed in a neutralising bath of dilute Hydrochloric Acid & rinsing
the seaweed in water
The washing of seaweed in a neutralising bath of dilute acid is advocated in numerous texts and
patents. However, it does give rise to the risk of unnecessary depolymerisation of the
carrageenan and would also be an added complication to what should be a simple process.
Accordingly we tested a simple rinsing process in fresh-water at ambient temperature of 5%
KOH-treated seaweed. Because the water temperature was at about 20C no leaching of
carrageenan was expected and none was seen. As a more rigorous test, Propane-2-ol (Isopropyl
Alcohol) was added to the used wash water. If any carrageenan was present in solution, the
alcohol would precipitate it as a floc. Almost no floc was seen.
Three half-hour washes at a 1:3.6 w/v dried seaweed:water ratio were made. The pH reduced
from 12.68 in the first wash to 12.37 in the third wash. Whilst not an apparently great reduction in
pH, the seaweed by the end of final rinse stage did not taste of alkali and the pH of a standard
1% carrageenan solution was 9.47, thus falling well within the pH 8-11 range specified by the
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FAO/WHO Codex Alimentarius, quoting the 68
th
JECFA (2007) monograph. Curiously, the EUDirective 2009/10/EC for E407a is silent on pH.
It is therefore recommended that the neutralisation stage is based on three half-hour washes of
seaweed in fresh-water at about a 1:3.6 w/v dried seaweed:water ratio. This will be carried out in
three stainless open-topped and unheated tanks, each with a net volume of 6.64 m3.
It is standard practice in such cases to use countercurrent flow techniques to minimise water
usage. Thus with each new batch the water is transferred to the next upstream tank and water in
the most upstream washing tank is subsequently discarded to waste or used to contribute thedaily 9.3 m3 required in the heated vessel. As with the previous stage, the lifting and lowering of
the basket at intervals will allow for proper circulation of the rinse water.
The seaweed at the end of this stage has increased in weight because of further water-
absorption. The bulk density of wet compressed seaweed after the three half hour rinses was
found to be 547 g/litre, approximating to 550 kg/m3. Therefore the weight of the basket contents
at the end of this stage of the process will be 3.65 MT (6.64 x 0.55).
It is important to note that by the end of the washing stage the seaweed is almost fully rehydrated
and has a moisture content of about 83%. The moisture content of fresh K. alvareziiseaweed is
typically 88%(13)
.
(d) Washing the seaweed in an optional bleaching step
Generally speaking, darkening of the processed seaweed would be a function of excessive
storage time and/or harsh process conditions. Since it is anticipated that the seaweed will be
delivered to the factory and processed within days of drying it will be in the best possible state to
avoid age-related deterioration. The use of reasonably mild process conditions addresses thesecond circumstance. A further consideration is that the end-use of carrageenan is usually in very
small quantities in very opaque and well-coloured foods such as meat pies and dairy products.
Thus perfect whiteness would be a spurious requirement.
The laboratory-made carrageenan, for the reasons just given, was a pale cream/tan colour after
the washing stage and oven-drying and probably acceptable in the market-place. Nevertheless
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the use of two recommended bleaching agents, Hydrogen Peroxide and Sodium Hypochlorite,
was tested.
Hydrogen Peroxide, though much used for bleaching wood pulp and paper (and blondes) is both
expensive and unstable. In its concentrated form it is highly corrosive and can be a fire risk or
even explosive under certain circumstances. Given its hazardous nature, it was satisfactory to
note that as a 1% solution for one hour it did not have much effect on the colour of laboratory-
made carrageenan.
Sodium Hypochlorite is not only much cheaper and relatively safer than Hydrogen Peroxide but,
as a1% solution for one hour, was found to be a much more effective bleaching agent on
laboratory-made carrageenan. However, the final product, though paler and whiter than a
comparable commercial sample, smelled strongly of chlorine. This could possibly be overcome by
neutralising the free chlorine with Sodium Thiosulphate - if permitted under all the various food
regulations.
Not only would this bleaching be an added process complication and cost, but subsequent testing
of the carrageenan showed it to be greatly compromised. Thus one batch of untreated 1%
carrageenan gel had a viscosity of 960 centipoise (cP) and a gel strength of 374 Oaklea units
(see Appendix 5 for definition). Hypochlorite-treated carrageenan gel from the same batch had a
viscosity of only 112 cP and a gel strength of just 47 Oaklea units.
It could be speculated that using lower concentrations of Hypochlorite for shorter periods of time
would reduce such dramatic deterioration of the carrageenan to more acceptable levels. We ask
why allow any deterioration in the fundamental functional properties of carrageenan when there is
so little justification in using it at all, given the points made in the introductory paragraph?
It is therefore suggested that, unless there is an overwhelming argument and demand from end-
user customers for bleaching, this stage is omitted from the process.
(e) Rinsing the seaweed in water
This stage has already been discussed in paragraph (c & e) above.
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(f) Drying and chopping the seaweed into chips or milling into powder
In the last paragraph of (c & e) above, it was pointed out that the moisture content of the seaweed
after the final stage of rinsing was 83%, only slightly less than that of fresh seaweed - 88%. It is
necessary to visualise that, in effect, drying it will be nearly the same as daily drying of half of the
entire Kaledupan fresh crop all over again. For food-grade product it would be mandatory to
consider an enclosed industrial-type drier to ensure regulatory limits on bacterial and fungal
contamination are adhered to.
Even for nonfood-grade sale, the small area of land at Buranga set aside for this project would be
too small to contemplate air-drying outdoors. Despite its near-equator location advanced current
solar power technology will be totally insufficient to cope(15)
.
In (b) above, it was shown that the daily input into the factory would be 10 MT/day of dried
seaweed. After processing and resulting rehydration it is calculated that production will typically
be about 25 MT/day of wet seaweed by this stage of the process.
Accordingly, advice was sought from the major UK company, specialising in crop drying
throughout the world, including the tropics - Alvan Blanch Development Company Limited(16)
.
Samples of the laboratory processed seaweed were sent to this company for evaluation, together
with details of start and finish moisture content values and proposed daily production capacity.
Their advice and budget quotation, based on one of their standard drier designs, has been
incorporated into the costings.
It is technically possible to incorporate a moisture recovery unit to the Alvan Blanch drier, using
seawater to cool the warm moist exhaust air via stainless steel heat exchangers. This may need
to be an option if sufficient local freshwater for the process is not available.
Such driers are inherently noisy (80dB(A)). It will be necessary to ensure that an acoustic enclosure (3
metre high solid or wooden wall with sound-deadening internal surface) is incorporated into the
design. In view of the adjacent housing in Buranga the design criteria for the drier and mill have
additionally ensured that the 25 MT daily drying requirement can be completed within a 16 hour
period - i.e. two 8 hour shifts. This will allow for shutdown between 10pm and 6am.
The drier can handle material as large as 150mm. However the seaweed fronds may well be
larger individually and also would interlink into bigger bunches, giving rise to blockage problems.
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Because of their leathery and springy nature when dry it is also greatly preferable to pre-chop
them before the drier stage rather than after. It was found that a conventional meat-mincer, with
an appropriate choice of plate-hole e.g. 8mm, would readily break the wet fronds down to asuitable crumb size (10mm). At this particle-size the material becomes free-flowing. Mincing or
grinding machines are commonly made in large sizes for industrial food-processing purposes
and are probably ideal for this function. They often have tin-plated worms and bodies and these
must be avoided stainless steel versions exist.
The milling of dried product would be done with either a hammer-mill or pin-mill. The advantage
of the pin mill is a gentler action with a consequent lower temperature-rise of product during
milling.
(g) Crane hoist and tank sizing
This additional section is devoted not to a process stage but to an important piece of equipment
the hoist. It will be expected to do much work.
It is envisaged from the above process description that four tanks will be required, one for the hot
caustic stage and three for the rinsing stages. They will be inline and separated by a minimum
distance - for access purposes. There is also a need for a space for the basket to be lowered to
ground level for filling and emptying.
Not only will the hoist be needed to lift the basket into and out of each tank but also to regularly
raise and lower the basket for the mixing purposes described previously. This may require
perhaps 11 lifts and lowering in each 4 hour cycle - if it is decided to lift the basket every half-hour
in the hot caustic tank and every quarter-hour in each of the rinse tanks. This would be 66 lifts
each 24-hour day. This number of lifts plus the need for accuracy of placement at each
progressive stage suggests that an electric hoist would be preferable to a manual one. Such lifts
can now be operated via a control box and proximity switches that would allow partial automation
of the process. The hoist would stop at each of a precise set of preset positions over the tanks,
removing the risk of guesswork or error. They can be fitted with two lifting speeds, allowing for
quick yet precise lowering.
A further consideration is how this may relate to tank size. A tank with a 2.2 m diameter would
have a gross capacity of about 3,800 litres for each meter of height. Using the earlier requirement
for a 7-7.5 m3 tank this would suggest a 2 m wall height. To this would need to be added a further
1 m allowance for support legs and cone or slope bottom. Space above the tank of over 2 m
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would be needed to allow for the basket to be lifted clear of the tank. Finally the hoist itself, its
hook and a spreader bar above the basket requires more space, possibly 1 m. The total height to
an overhead steel rail would therefore be6 m.
If the rail height is considered excessive - since it would need to be incorporated within a yet
higher building - then a solution may be to double the number of tanks but give them a 1 m wall
height. This would reduce the height requirement by 2 m to 4 m.
For the purposes of this report the former, taller, option will be used for costing purposes. The
weight of the basket would be 3.65 MT for the fully-wetted contents and an estimated 0.5 MT for
the stainless steel basket and lid, totalling 4.15 MT. This is well within the range of such hoists
and their gantry supports. These gantry supports create an internal steel frame and ensure that
no part of the weight to be lifted is transferred to the building structure.
(h) Waste disposal
This additional section covers the very important consideration of best-use of the major waste
streams from the process.
It has been established that KOH will be required for carrageenan product made for the European
Union. Also it is suggested that a major waste stream of 9.3 m3 of
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(K2SO4) - or more likely Potassium and Sulphate ions, since K2SO4 is readily soluble. However,
analysis of PES carrageenan shows it to contain about 4% Potassium. Some of this may be from
retained KOH
(13)
. Assuming 3.5 MT of PES carrageenan is produced daily then 0.14 MT ofPotassium ion is conserved within the product.
To this can be added the minor waste stream of wash-water from the trio of counter-current wash
tanks. This will be a rate of one tankful per run and will total 39.8 m3 (6.64 m3 x 6) per day in
volume terms. However 9.3 m3 will be needed for topping-up the main process tank (see section
(b) above) so the net result will be a surplus of 30.5 m3 of very low concentration KOH solution
leached from the washed KOH-treated seaweed. If it were added to the main waste stream then
its contribution of KOH will already be accounted for in the previous paragraph it is merely
recovered at a different point.
Combining the Potassium contribution from both sources (the natural content present in seaweed
and the added-chemical content) and subtracting the amount retained in the PES product results
in a waste stream containing 0.55 MT a day of valuable ionic Potassium.
The volume of liquid in the combined major and minor waste-streams will be 39.8 m3/day. It
would however make sense to keep these separate in order to make a most useful compound
fertiliser from the main (concentrated) waste stream.
Therefore the annual requirement for process freshwater will be 12,000 m3 (39.8 x 300). To this
needs to be added water for drinking & cooking, laboratory and washing-down.
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It is not within the remit of this report to discuss the detailed agronomy of Kaledupa. However
some simple comments can be briefly made.
Census data indicate that 81% of fishing households on Kaledupa grow cassava and 62% grow
coconut. In addition, 13% grow corn, 12% grow cashews, and 9% grow garlic. Cacao is grown
on a few farms and fruit trees and green vegetables are grown most commonly in house
gardens, or yards(18)
.
Elsewhere in Indonesia it has been noted that Potassium deficiency often becomes a problem
when cassava is planted continuously on marginal soils. The reasons quoted for this are that the
crop extracts a large amount of K; that many cassava soils have a low K content and that farmers
rarely apply K fertilisers(19)
.
A high response of other food crops (rice and maize - i.e. sweetcorn) to Potassium fertiliser
application in Indonesia was also found(20)
.
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It has been shown Potassium Chloride application of up to 200 kg KCl/ha linearly increased
cassava yield, and would indirectly reduce soil loss due to erosion
(19)
.
This translates toapproximately 100 kg of Potassium ion/ha/annum. Thus the daily output of Potassium in the
waste-stream is sufficient to fertilise 5.5 ha (0.55 MT of K x 1,000 / 100) of local crop. This
translates to 1,650 ha annually from the 300-day production output.
It is estimated that fishing and farming households utilise an estimated total of 5,000 ha of land on
Kaledupa, or 65% of the land area(18)
. The conclusion can be made that the optimal Potassium
crop requirements of one third of the entire island of Kaledupa might be met from this waste
stream.
Clearly the practical difficulties of distribution and terrain will reduce the potential benefit. A four-
wheel drive tractor and tanker-trailer will be required to provide a delivery service. It may be
necessary to temporarily store the waste-stream during the monsoon periods, due to difficulty of
transport and spreading at that time and possible excessive leaching from the soil.
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It has also been shown that Nitrogen and Phosphorus are also important in increasing cassava
yields. Yield increases, ranging from 4 to 24 MT/ha fresh roots, have been reported when 200 kgof urea (a source of Nitrogen) and 100 kg of Triple Super Phosphate were applied, compared to
that without fertiliser(21)
.
For cassava crops, the main cultivated plant on Kaledupa, opinions differ as to the optimal
proportions of NPK required though Potassium is always noted as the most important nutrient.
These vary from 1:3:3 N-P-K(22)
to 1:1:2 N-P-K(23)
- the former recommendation being the most
recent and using least nitrogen. Excessive application of nitrogen fertilisers can lead to high
Hydrocyanic Acid (HCN) content and bitterness of the tubers (24).
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Coconut palms are also responsive to high potash fertiliser(25)
.
Given these potential crop benefits, it would be clearly beneficial to consider neutralising the very
alkaline (pH 12-14) waste-streams with acids that could contribute, at least in part, to creating
such a balanced fertiliser. Therefore Nitric Acid (HNO3) and Phosphoric Acid (H3PO4) would be
ideally suited to this purpose.
The process of neutralisation is fundamentally the balancing of H+ and OH- ions to create a pH of
7. In this case the excess alkaline OH- ions are entirely derived from the KOH added during
processing. So each OH- ion remaining in the waste stream requires a matching H+ ion from an
acid.
From the formulae of the two acids (Nitric Acid (HNO3) and Phosphoric Acid (H3PO4)) it can be
seen that Phosphoric acid could theoretically contribute three H+ ions per molecule and so
neutralise three OH- ions - compared to the one H+ ion present in a Nitric Acid molecule.
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However the situation is not so straightforward because Phosphoric Acid is considered a
relatively weak acid and does not dissociate in water as well as Nitric Acid - a strong acid. Thismeans that such simple proportions cannot be applied.
Because Phosphoric Acid is polyprotic it can nevertheless loose more than one proton (H+) and
so has three Acid Dissociation Constants (pKa values) for its three protons. However two of
these protons are fairly reluctant to appear. From an examination of these pKa values for
Phosphoric Acid it can be concluded that it will fairly readily provide one H+ ion but much less
readily its other two. So it is safer to anticipate its neutralising power to be similar to Nitric Acid
i.e. one to one.
Returning to the neutralisation requirement for the process, previously it was calculated that the
waste-stream had a maximum net KOH daily output of 0.419 MT. A mixture of the two acids
should be used in order to try to achieve the preferred 1:3 N:P ratio mentioned previously. The
calculation needs to be based on their standard commercial strengths of 68% for Nitric Acid and
85% for Phosphoric Acid. Accordingly, Appendix 4 sets out the data and calculations.
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The conclusion is that, using a required 1:1 mix of concentrated Nitric and Phosphoric Acids,
about 9.3 m3 of high-potash compound fertiliser solution could be derived from the waste stream
with a N-P-K value of about 0.8 : 1.6 : 5.9 by weight or, more accurately, as would be officially
termed in the UK, 0.8% (0.8% N) - 3.7% (1.6% P) - 7.1% (5.9% K). See note in Appendix 4 for
explanation.
By estimating a monetary value for this N-P-K in Appendix 4 and costing a tractor/trailer delivery
service it is calculated that about 66% of the cost of chemicals used in the process can be
recovered as a valuable and non-polluting fertiliser.
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Note:
An unknown but useful extra quantity of Sulphate will also be added from the dehydration
reaction step during hot KOH treatment, creating soluble Potassium Sulphate compound.
The beneficial use of seaweeds as fertiliser has been known for centuries. Apart from their high
Potash levels and their organic and cellulose content, the benefit is often due to the minor
components (e.g. Magnesium) and the trace elements (e.g. Iron & Zinc) present. It can be
reasonably expected that the neutralised waste-stream will have a considerable percentage of
these micronutrients. These would contribute to reducing any soil mineral deficiencies that may
be present on Kaledupa. For example, cassava is sensitive to Zinc deficiency(26)
.
Important plant growth regulators and promoters present in seaweed, such as auxins, cytokinins,
abscisic acid, betaineand gibberellins, may survive the process conditions and also contribute to
the fertiliser value.
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Note:
The alternative and cheapest way to neutralise the waste stream would be to use concentrated
Sulphuric Acid, which would give a daily equivalent of 402 kg of dissolved (ionised) Potassium
Sulphate, derived from 180 kg of the Potassium present. This would still leave 370 kg of
Potassium ion in the waste stream. It would be a very unbalanced fertiliser and only useful where
adequate nitrogen and phosphorus are already present in the soil probably unlikely on much of
Kaledupa.
(i) Power, heat and fuel
In order to process 10 MT a day of dried seaweed - causing it to fully rehydrate and then drying it
in order to produce 3.5 MT of carrageenan product, the factory will require substantial amounts of
energy for heat and power.
Calculations suggest the following:
Boiler size for process heating = 110 kWh assuming 95% boiler efficiency
Generator for operating mill, drying fans, pumps, mincer, minor machinery, lighting, office
equipment, etc = 150 KVA = 120 kWh electrical output, requiring 300 kWh input
assuming 40% efficiency
Burners for product drier = 1.2 MWh
So at peak demand there is a maximum requirement of just over 1.61 MWh for 16 hours and then
about 260 kWh for the remaining 8 hours a day.
This equates to 27.84 MWh a day and 8,350 MWh a year.
This will need to be supplied from within the factory premises and the choice of fuel is critical for
cost and environmental reasons.
This choice appears to be between diesel and liquefied petroleum gas (LPG). This is because
natural gas in the form of compressed natural gas (CNG) or liquefied natural gas (LNG) does not
yet appear to be available on Kaledupa. It may become so, in the future, as Indonesian energy
companies like PT Pertamina further develop the countrys large oil and gas reserves. Indonesia
has 1.7% of world reserves of natural gas and 0.4% of oil(27)
. In 2008 it produced 69.7 billion
cubic metres of natural gas and 366 million barrels of oil. By comparison the UK is rather similar,
producing 69.6 billion cubic metres of natural gas and 564 million barrels of oil in 2008(27)
.
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Appendix 3 shows that diesel is double the cost of LPG when expressed in volume terms.
However, diesel @ 38.6 MJ/litre is more energy-dense than LPG @ 26.8 MJ/litre - i.e. 44% more.
When the cost is adjusted to reflect this, the price difference between these fuels is 39%, the LPG
still being significantly cheaper.
The drier is by far the greatest consumer of fuel, because it needs to evaporate over one tonne
an hour of water during its 16 hour daily cycle. It is the most expensive consumable and any
savings, however small, will have a large impact on production costs. When the alternative fuel is
40% more then the argument for LPG becomes overwhelming, if all other considerations are
equal. But they are not, they are even more persuasive.
Another powerful financial reason for choosing LPG is that, because it is a clean-burn fuel, it can
be used to direct-fire the drier i.e. the exhaust gases are efficiently allowed to pass through the
drying product. Diesel, on the other hand, is a relatively dirty-burn fuel, even with good servicing
of burners and choice of a high-quality low-sulphur diesel fuel. For a food-grade product it would
be mandatory to use diesel only as an indirect source of heat. So there would be an added and
substantial capital cost of providing a large air-to-air heat-exchanger - plus a huge drop of 40% in
drying efficiency as a result(16)
. Thus the diesel version would consume 40% more fuel than the
LPG choice a very significant added cost. It will also require frequent cleaning to maintain its
original efficiency, due to sooting by diesel smoke.
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There are also considerable very environmental benefits in using LPG, a highly important
consideration in the near pristine and unpolluted atmosphere of Buranga - and with the village
adjacent to the proposed factory. These can be briefly listed as follows:
LPG is a low carbon emitting hydrocarbon fuel available in rural areas, emitting 17% less
CO2 per kWh than diesel, due to its lower Carbon/Hydrogen ratio(28)
.
LPG engines produce 120 times less PM (Particulate Matter) than diesel engines(28)
.
LPG engines produce 20 times less NOX (Nitrogen Oxides) than diesel engines
(28)
. LPG engines produce 9 times less SO2 (Sulphur Dioxide) than diesel engines
(28).
LPG engines produce 5 times less CO (Carbon Monoxide) than diesel engines(29)
.
The numerous health concerns from the above air pollutants are well summarised on the US
Environmental Protection Agency website(30)
.
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LPG engines are generally quieter than diesel engines, due to reduction of diesel knock(31)
.
As well as environmental benefits there are technical advantages to LPG engines. They have
longer service intervals and longer service life due to the less polluting effects of the fuel on the
engine oil and lower vibration levels(31)
.
Diesel does have a minor advantage over LPG in some respects:
Storage of diesel, although requiring 110% bunding to safeguard from catastrophic leaks,
is relatively simple, using double-wall plastic or steel tanks. Conversely LPG tanks are
pressure vessels and have to be made of steel to strict international safety standards e.g.
ASME Sect. VIII Div.1 and possibly requiring a CCS Certificate in Indonesia.
Previously it was shown that diesel is 44% more energy-dense than LPG. So for the
same amount of stored energy diesel tanks need to be about 44% smaller than LPG
tanks.
Diesel may initially be more acceptable to local opinion. Unless reassured, Burangan
citizens might have concerns over LPG explosions the reaction sometimes found in
the current Indonesian government-sponsored Kerosene to LPG Conversion Program
using PT Pertamina(32)
.
Fuel storage requirements need to be considered. If LPG is selected then, using the above 27.84
MW/day consumption rate and the energy-density of propane being 7.5 kWh/litre(33)
, the total
volume of LPG consumed will be 3,712 l litres/day or 111,400 litres/month.
Because of the weight limit at Buranga dock, the tank must weigh no more than 10 MT in order to
be unloaded(34)
. The largest LPG tank to fulfill this weight requirement is 24,000 litres. This is
sufficient for about 6.5 days of production. So five such tanks will secure a minimal 33 day
(>month) supply.
If diesel were to be the sole fuel source then, having an energy density of 10.75KWh/l but
requiring 40% extra for drier heat-exchanger losses) there would need to a storage requirement
of 3,626 litres /day (27.84 x 1,000 x 1.4 / 10.75) or 108,770 litres/month. Typically, a fully-bunded
(110%) twin-wall steel horizontal tank of 40,000 litres capacity would weigh 8.5 MT net. Therefore
three such tanks would be required for a minimal 33 day (>month) capacity.
There is a limited argument for a hybrid system LPG for the drier and diesel for the generator.
The environmental arguments against diesel still remain, though the quantity of diesel fuel used
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would be significantly less 560 litres/day. The problem is that LPG generators of the required
size are difficult to source they generally are smaller - with natural gas models taking their place
at or below this 120KW size point. However a solution would be to have two smaller LPG
generators create the total power requirement. A possible advantage is that one of these could be
shut down during the night-time when lower electrical power is needed.
It has been assumed above that the generator will be powered by a conventional reciprocating
piston engine. These are easy to source and relatively straightforward to maintain, often using
local labour. However, as the source of prime power, rather than on stand-by duties, they will
need considerable maintenance input.
A typical diesel-engine would require an oil and filters, etc, service every 500 hours (or 21 days
@ 24 hours/day), an intermediate top-end overhaul every 10,000 hours (costing 35% of the
purchase price) and the most major top and bottom-end overhaul at 20,000 hours. The cost of
this last overhaul can be as much as 70% of the original purchase price. The top-end and top
and bottom-end overhauls are too complex for local servicing and will require the use of
specialist staff provided by the manufacturers agent. In view of its critical contribution to the daily
operation of the factory and the near-new cost of major servicing it would be our
recommendation to fully replace the generator at that stage - rather than risk a major failure in the
future.
The generator annual running time is 7,200 hours (300 x 24 hours). This equates to a life
expectancy of about 2.75 years for such a prime-power unit. This is an average figure, very
much dependent on the quality of servicing and fuel used. There is a good argument for
alternately running two such generators, which would substantially increase the margin of safety
of the process, allow for maintenance downtime and for breakdowns. It would also double the life
expectancy to 5.5 years.
A (surprising) alternative to the use of a piston engine is to use a micro-turbine. Its components
include a compressor, a recuperator (exhaust gas heat-exchanger), a combustor, a turbine, and a
generator. The turbine engine is air-cooled and supported on air-lubricated compliant foil
bearings. The compressor impeller, turbine rotor and generator rotor are all mounted on a single
shaft, which comprises the only moving part in the engine. Power electronics are solid-state
producing three-phase alternating current output power from the high-frequency alternating
current engine output. It is therefore an extremely simple, if sophisticated, piece of engineering.
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Micro-turbine generators are very compact, vibration-less and quiet. Because of these qualities,
together with their inherent reliability and long maintenance intervals, they are much-used on off-
shore oil rigs and in remote user-critical locations. They can be provided in a CHP configuration
see below.
Micro-turbine service intervals are air-filter change and injector-clean every 8,000 hours or 333
days (they use no oil). Injector replacement and turbine exit temperature probe replacement at
20,000 hours. Replacement of turbine wheel and air bearings every 40,000 hours and whole
engine change every 80,000 hours - at about 33% of original purchase price. All maintenance
would need to be carried out by specialist staff, provided by an existing Jakarta-based
supplier/distributor.
When considering generator specification, one common optional extra is Combined Heat and
Power (CHP). As with all power supplies, the conversion of fuel energy to electrical energy is
only about 40% efficient - at best. The rest is lost as heat. By using heat exchangers, up to 50%
of the heat input can be usefully recovered, with just 10% losses i.e. totalling 90% fuel efficiency.
The maximum benefit from CHP is gained if heat is always required as well as power. This is
exactly the case in the hot-water alkali conversion stage of the process, which will operate 24
hours a day.
As with LPG/Natural gas generators, it is difficult to source reciprocating powered generators with
this additional feature below a breakpoint of about 150KW total output. However the micro-turbine
does come with the CHP option at a smaller size.
For 16 hours a day the generator will by running at high load, powering the drier fans and mill as
well as the rest of the process. This is beneficial for a conventional piston-powered generator,
which works more efficiently and with fewer maintenance issues when under full load. For the
remaining 8 night-time hours the generator will only be on part load, powering the early, less
power-hungry, stages of the process. It might be approximated that overall the generator is used
at 75% of maximum i.e. providing about 110KW of heat (300KW x 0.75 x 0.5). This would provide
(by coincidence) exactly the expected heat required (see above) for raising tank temperature to
60C, eliminating the need for a boiler, except for emergency or standby purposes.
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(j) New versus second-hand
There are a few good reasons for seeking and installing second-hand equipment. It represents
environmentally beneficial re-cycling and sometimes can be a cheaper option
However our experience of second-hand process plant for a food additive manufacturer in the UK
has been mixed. The following are some points to consider:
Whilst the initial purchase price will be cheaper than new, it will rarely be cheap. When
the costs of modification, including replacing out-of-date, unreliable or worn-out items like
motors, bearings, seals or flanges are added then even the real price saving can be
marginal.
The delay in design and construction of the factory can be very considerable if the size,
shape or utilities requirements of the items are not known in advance. For example, the
existing entry and exit points for valves, drains etc on second-hand tanks are usually in
the wrong place to what is now required. The outcome is an often less than ideal
compromise, requiring much modification and resulting in a much more protracted build
time and, in this example, more complex and less efficient plumbing than necessary.
The management time and effort spent looking for suitable items can be very
considerable. It can often be better spent on other priorities.
Items coming from non-food factories will not be permitted in food factories, limiting
choice yet further.
Sourcing of suitable or nearly suitable items will depend on the dumb luck of them
happening to be available at that precise time. Luck should not be a part of factory
design.
There is a strong likelihood that major customers operating due diligence schemes and
regulatory authorities concerned about, for example, food hygiene or personal safety, will
want confirmation that all parts of the factory conform to appropriate current internationalstandards. Old or out of date equipment may well not pass such scrutiny.
In the context of this project the great distance from Kaledupa to major cities where spares or
repairs may be sought means that new, reliable equipment and machinery, guaranteed by their
manufacturers or suppliers, must be the preferred option. The prolonged breakdown of any link in
the production chain will have disastrous consequences on the credibility of the factory, both to
the suppliers of the raw materials and to the customers for the finished product.
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(k) Quality assurance and quality control
Providing that all staff and workers are diligent, conscientious and use their common-sense there
is nothing in this section that should be of concern.
Quality assurance (QA) refers to planned and systematic production processes that provide
confidence in a product's suitability for its intended purpose. It is a set of activities intended to
ensure that the products satisfy customer requirements in an ordered, reliable fashion.
Unfortunately QA cannot absolutely guarantee the production of quality products, but makes this
more likely.
Two key principles characterise QA:
Fitness for purpose - the product should be suitable for the intended purpose
Right first time - mistakes should be eliminated.
QA includes regulation of the quality of raw materials, products and components; services related
to production; and management, production and inspection processes.
It is important to realise also that quality is determined by the intended users, clients or
customers, not by society in general - it is not the same as 'expensive' or 'high quality'. Even
goods with low prices like carrageenan can be considered quality items if they meet a market
need.
So QA should represent an attitude of mind by all employees but especially by management,
whose actions or lack of action can be critical.
Whilst quality control (QC) emphasises testing and blocking the release of defective products,
quality assurance is about improving and stabilising production and associated processes to
avoid, or at least minimise, issues that led to the defects in the first place. However, QA does not
necessarily eliminate the need for QC - some product parameters are so critical that testing is still
necessary just in case QA fails.
It will be essential for a QC laboratory to be located within the factory premises though preferably
not the factory itself. The existing harbour-masters disused building would be an ideal place for
the laboratory, as well as for offices and possibly storage of finished product.
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The laboratory staff will undertake a number of activities including:
The analysis of incoming dried seaweed raw material for moisture and contaminants.
The measurement of process parameters such as pH at the various intermediate stages
and moisture content of product exiting the drier.
Analysis of product for gel-strength and viscosity to fulfill customers requirements.
Analysis of product for conformity to international food-additive standards such as EU
E407a, theUSA Code of Federal Regulations and the FAO/WHO Codex Alimentarius
(which refers to JECFA specifications).
Testing the waste-stream for conformity to pre-determined standards.
Providing rapid feedback to workers and managers of out-of-specification products or
process materials.
The laboratory should be well equipped to carry out these measurements efficiently and
accurately, using the fundamentals of Good Laboratory Practice (GLP). This is a set of principles
that provides a framework within which laboratory work is planned, performed, monitored,recorded, reported and archived. GLP helps assure customers and regulatory authorities that the
data submitted are a true reflection of the results obtained and can therefore be relied upon.
GLP should not be confused with the standards of laboratory safety - wearing appropriate gloves,
protective glasses and clothing to handle materials safely.
The management should also implement Good Manufacturing Practice (GMP) insofar as it
applies to food-additives. GMP requires a quality approach to manufacturing, enabling factories to
minimise or eliminate instances of contamination, mix-ups, and errors. This in turn, protects the
customer from purchasing a non-conforming product.
GMP addresses issues such as record-keeping, sanitation, cleanliness, equipment verification,
process validation, and complaint handling. Most GMP requirements are very general and open-
ended, allowing a manufacturer to decide individually how to best implement the necessary
controls. This provides much flexibility, but also requires that the manufacturer interprets the
requirements in a manner which makes sense for each individual business.
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(l) Safety
The process requires the storage and use of relatively simple chemicals but these can be highly
dangerous to people and property because of their strongly acidic or alkaline nature, their
quantity and often their concentrated form. Likewise the fuels are commonplace but are stored
and used in large volumes, representing another potential hazard.
It is highly advisable for an assessment of these the risks to be made. There will be a need to: Identify the hazards.
Decide who or what might be harmed and how.
Evaluate the risks and decide on precaution.
Record these findings and implement them.
Regularly review the assessment and update if necessary.
In the UK, The Health and Safety Executive expects any business employing more than 5 people
to have a Health & Safety Policy and operate appropriate health and safety systems(35)
.
Also in the UK, the Control of Substances Hazardous to Health (COSHH Regulations 2002)
require employers to assess the risks from hazardous substances and take appropriate
precautions(35)
.
All manufacturers of chemicals are required to provide a material safety data sheet (MSDS)withtheir product. At the very least, this MSDS should be the starting point for the risk assessment.
All workers must be provided with protective clothing and trained to use them at all times.
Warning notices of hazards must be displayed. Emergency wash-down showers and eye-wash
stations must be provided.
The extreme isolation of the site from the nearest hospital means that a properly equipped
emergency room is required for treatment of major or minor accidents. At least one person on
every shift must be well-trained in first-aid. The local medical service must be made aware of the
chemicals being used and be equipped and trained to respond quickly and effectively.
General training of all workers on safety issues must be regularly carried out. No new worker
should be permitted to commence work without a proper induction course.
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Members of the public and especially children must be kept out of the site by providing a secure
fence and gates.
The aim of all these precautions is to have an accident-free site permanently.
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Business Model
Note:
For standardisation purposes all prices quoted are in US Dollars (USD).
Approximate exchange rates at time of finalisation of this report (early June) are 1 USD ($) =
10,000 IDR = 0.60 GBP.
Wherever possible prices have been derived from Far East suppliers, using websites such as
Alibaba and EC Plaza the two premier B2B online marketplaces.
All chemical prices are from these Asian sources and are quoted FOB(Free On Board) the
country of origin see Appendix 3. They assume FCL (Full Container Load) quantities.
Elsewhere, particularly for specialist equipment, UK suppliers have been approached for their
budget estimates. These have been converted to USD and are FOB the suppliers local port.
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1. Capital Investment
Note:
All company product specifications or model numbers or equipment photos are provided for
illustrative purposes only.
No endorsement of such products is implied nor are any of the companies mentioned contracted
to supply at the prices indicated.
There is an assumption that the land and existing harbour masters building and two other smaller
buildings at the dockside in Buranga are being donated to the project by the Wakatobi
Government.
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The main building can be well-utilised as offices and laboratory.
These offices will require excellent and reliable telephone and fast broadband (IT) communication
links perhaps via satellite.
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The smaller building could possibly be used as the finished-product store.
An additional building is required to house:
The process machinery (high-roof)
At least a weeks worth of incoming dried seaweed raw material
At least a months worth of the process chemicals
It will need to be vermin-proof and bird-proof.
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OZ-UK American-barn steel-frame building - erected & fully clad 600 m3 @ $130 /m3 = $78,000
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Secure perimeter fencing and gate 400 m @ $50 /m = $20,000
Peal stainless sorting conveyor 2 m x 0.6 m variable speed = $9,600
Abus Cranes triple goalpost gantry & monorail 4MT electric hoist - with automation = $32,000
Suncombe Tanks (ST) single insulated 8,000 litre stainless tank open-top = $27,000
ST Three uninsulated 8,000 litre stainless tanks open-top = $67,000
ST Two stainless baskets and lids for above tanks = $12,000
Note:
Indonesian-sourced tanks & baskets may be significantly cheaper @ $2,500 each uninsulated
per tank and $350 per basket. However, are only available in lower-grade 304 grade stainless -
not suitable for food processes. Suncombe UK tanks are higher-grade 316 stainless.
APV stainless steel plate heat exchanger = $18,000
Miscellaneous pumps for process = $12,000
Kolbe Stainless mincer-grinder 15KW with feed hopper = $49,000
Alvan Blanch (A-B) belt conveyor to feed drier = $24,800*
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A-B SPD-19,000crop drier complete with 1.2 MW LPG furnace and fans = $221,000*
A-B Additional air-to-air heat-changer if diesel fuel is used = $31,200*
A-B Hammer-mill with 30KW motor = $20,800*
Note:
This hammer-mill and associated cyclone, etc, in stainless is about $150,000
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Stainless Alpine Hosokawa Sugarplex 315 pin-mill with improved performance and more compact
design is about $160,000
A-B Cyclone with 15KW motor = $17,500*
A-B Centrifugal sifter = $13,000*
A-B Returns screw = $4,600*
A-B Magnet = $1,100*
A-B Screw discharger & sacking hopper = $10,000*
A-B Sack weigher = $10,500*
A-B Sack stitcher = $2,400*
A-B Control panel for drier and hammermill = $21,600*
Note:
A-B prices listed are for mild-steel suitable for petfood grade product
A-B stainless steel contact parts option for foodgrade product = $240,000 extra.
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Either: Hubei ChengLi 5 x 25,000 litre LPG storage tanks = $60,000
Or: Dale 3 x 40,000 litre 110% fully-bunded twin-wall diesel tanks = $96,000
Viessmann Vitodens 2 x 60kW cascade-type LPG boilers = $11,100
Generator:
Note:
All prices are for two units
Alternative 1 (USA/UK - Finning) Caterpillar Olympian GEP165 diesel (120KW prime power)
generators + fully acoustic container (super-quiet) = $132,000
Alternative 2 (USA/UK Qingdao China agent) Deutz/Stamford 160GF-T LPG (158KW prime
power) generators + canopy = $124,000
Alternative 3 (USA Global Power Systems India agent) GM/Kohler 80RZG LPG (64KW
prime power) generators including synchronisation panel = $56,500
Alternative 4 (USA Capstone Solusi Mitra Jakarta agent) C65 (65KW prime power) LPGmicro-turbine generators = $130,000 (diesel option + $46,000)
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Alternative 5 (USA Capstone Solusi Mitra Jakarta agent) C65 ICHP (65KW prime power)LPG micro-turbine generators + CHP function = $181,600 (diesel option + $46,000). Using LPG,
this is the preferred generator option.
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TCM 2-wheel-drive LPG forklift = $22,500
JCB 2155+ 4-wheel-drive/steer tractor (150HP) and 10,000 litre trailed-tanker = $114,000
Harlequin 10,000 litre twin-wall plastic 110% fully-bunded diesel tank for 4WD tractor = $6,200
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Laboratory equipment; typically moisture balance, precision balance, viscometer, water-bath, gel-
strength tester, pH meter, benching and glassware = $23,000
Construction labour costs and incidentals electrical wiring, plumbing, etc = $60,000
Sub-Total:
In foodgrade (stainless) option using LPG = $1,390,300
(add $31,200 if diesel fuelled for heat-exchanger)
In petfood (mild steel) option using LPG = $1,150,300
(add $31,200 if diesel fuelled - for diesel heat-exchanger)
Note:
All above prices FOB - add 20% for transportation.
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Capital Investment:
Full Total Cost including transportation:
In foodgrade (stainless) option using LPG = $1,668,000
(add $31,200 if diesel for additional heat-exchanger)
In petfood (mild steel) option using LPG = $1,380,000
(add $31,200 if diesel - for additional heat-exchanger)
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2. Running Costs
Note:
Appendix 3 summarises April-June 2009 commodity prices for all items.
2.1 Raw material
The following is extracted from our November 2007 Report:
Factory buying-in price is typically 1,000 IDR/kg above farm-gate price, this differential being the
costs and profit margin of two tiers of sub-regional and regional collectors. The farmers closest to
the plant (factory) site may immediately benefit from this by delivering their crop in person. Even
the more distant ones will cut out the regional collectors buyers margin and only incur the sub-
regional collectors margin of 300 IDR/kg - so should benefit by about an additional 700 IDR/kg.
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Thus the average farmer producing 400kg/month would instantly gain an extra 280,000-400,000IDR or 15-21 per month.
It remains entirely reasonable to buy-in at factory-gate prices. To do otherwise would be to give
the factory the advantage of a de facto subsidy, equivalent to the intermediarys price margin.
Furthermore the growers need an inducement to sell to this factory rather than to their existing
collectors. If the factory only paid the farm-gate rate then no such incentive would be on offer.
These figures were based on the then current farm gate price of4,500 IDR/kg. It is now over 10%
more at 5,000 IDR/kg - or $0.49/kg. To this should now be added the above differential of 1,000IDR/Kg or $0.10/kg.
The buying-in price will therefore be 6,000 IDR/kg or $0.59 /kg.
The annual crop requirement has previously been given as 3,000 MT.
The annual purchase cost of dried seaweed will be $1,770,000 (3,000MT x 1,000 x 0.59)
2.2 Chemicals
Note:
All prices are FOB the suppliers local port.
Earlier it was calculated that 419 kg/day of 90% KOH was required for the process.
For a 300 day/year production this equates to 125.7 MT/annum of 90% KOH dry prills or flakes
(Note that most of the 10% impurity is NaOH).
The annual purchase cost of 90% Potassium Hydroxide @ $1,241/MT is $156,000
Adding 20% for transportation - annual purchase cost of 90% Potassium Hydroxide is$187,000
In Appendix 4 calculations suggest that a mixture of 259 litres of 68% Nitric Acid and 280 litres of
85% Phosphoric Acid will be required to neutralise daily output of KOH of 419 kg in 9,300 litres
water.
For a 300 day/year production this equates to:
77,700 litres of 68% Nitric Acid @ relative density of 1.4 kg/litre = 109 MT
The annual purchase cost of 68% Nitric Acid @ $455/MT = $49,600
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Adding 20% for transportation - annual purchase cost of 68% Nitric Acid = $60,000
84,000litres of 85% Phosphoric Acid @ relative density of 1.69 kg/litre = 142 MT
The annual purchase cost of 85% Phosphoric Acid @ $680/MT = $96,600
Adding 20% for transportation - annual purchase cost of 85% Phosphoric Acid = $116,000
The combined delivered cost of Nitric Acid and Phosphoric Acid is $176,000
Note :
The cheaper alternative, though not adding beneficial nitrate and phosphate to the waste stream,
is to use Sulphuric Acid.
In Appendix 4 calculations suggest that 230 litres of 98% Sulphuric Acid will be required to
neutralise daily output of KOH.
For a 300 day/year production this equates to:
69,000 litres of 98% Sulphuric Acid @ relative density of 1.84 kg/litre = 128 MT
The annual purchase cost of 98% Sulphuric Acid @ $182/MT = $23,300
Adding 20% for transportation - annual purchase cost of 98% Sulphuric Acid = $28,000
This represents a cost saving of $148,000 when compared with the Nitric Acid - Phosphoric Acid
mixture but gives a highly unbalanced and possibly unusable fertiliser.
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2.3 Fuel
Note:
Prices include delivery.
Earlier it was calculated that 3,712 litres/dayof LPGwas required for the process.
For a 300 day/year production this equates to 1,113,600 litres.
The annual purchase cost of LPG @ $ 0.36/litre = $401,000
If diesel were chosen (despite its poor environmental credentials) then it was previously
calculated that 3,626 litres/day would be required for the process.
For a 300 day/year production this equates to 1,087,800 litres.
The annual purchase cost of diesel @ $0.60/litre = $653,000
This represents an additional cost of $252,000 when compared with LPG
30,000 litres/annum diesel will be required for 4-WD tractor @ $0.60/litre = $18,000
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2.4 Labour
There will be three 8-hour shifts a day. The num