Self-adjustingWipers

Tramp OilOutlet

SkimmingBelt

II

Programme for Industrial Sustainable Development (PISD-II) Sugar Sector

LAHORE:Plot # 18, Perfect SITE, 22km FerozpurRoad, near Masjid-e-Ibrahim, LahoreTel: 042-35273741-46 Fax: 042-35273750e-mail: ctpt@pisd.com.pk

KARACHI:Regional Programme ManagerPlot # 39 3rd Floor, Principal House,22nd Commercial Street, Off Khayaban-e-Ittehad,Phase-II, Extention, DHA, KarachiTel: 021-35893341-2, Fax: 021-35893340,e-mail: ctptkhi@pisd.com.pk

FAISALABAD:House # 371-A, Gulistan Colony,Near Millat Chowk, FaisalabadTel: 041-8581816 Fax: 041-8581295e-mail: ctptfsd@pisd.com.pk, pisd@pisd.com.pk

Disclaimer: This leaflet contains information collected and provided in good faith and is based onliterature review and field experience of the project team. The project accepts no liability for accuracyof information obtained from third party resources.

April 2011

CONTACT DETAIL:

URL: www.cpi.org.pk, www.pisd.org.pk

Oil Skimmer in Sugar Industries

In most sugar industries, oil and grease pollution is mainly caused

because of lubrication of chains, bearings, groove rolls etc. On

an average, sugar mills consume 18 to 20 liter of lubricants and

0.3 to 0.5 kg of grease per 100 ton cane. In sugar mills, the

pollution load of oil and grease is varied; it ranges from 150 to

250 kg/day. Upon installation of an oil skimmer, approximately 80

to 90 percent of previously wasted oil can be recovered. This

recovered oil mixture can be reused within the sugar mill itself or

it can be sold to a secondary user.

Most sugar mills use rubber belt type oil skimmers. A belt of

stainless steel is lowered into the liquid that needs to be treated.

The belt then passes through special wiper blades, which remove

O i l S k i m m e r

Application of Oil Skimmer

Oil skimmer can be used for treatment of effluent in any industry or process that releases oil as a waste product.It can be installed at sugar industries, petroleum and petrochemical industries, edible oil industries, thermalpower stations, lubricant/oil manufacturing industries, soap factories, fertilizer industries, chemical industries,airports, paints, enamel and varnish manufacturing industries, glass manufacturing industries, food processingindustries, steel industries, textile mills, tool rooms, CNC machine shops and locomotive industries.

In case of sugar mills; it is most suitable if two oil skimmers are installed in sync - one on mill house drain andthe other on final drain.

Upon recommendation of PISD, a sugar mill installed multiple oil skimmers and recovered the invested cost

in just one crushing season. The recovery period of investment may vary for different mills as it depends upon

the amount of oil/lubricant being used during the processes and the use of recovered oil.

References:· w w w. s m b e n g i n e e r s . n e t· Case Studies: CTPS Audits· www.oilskimmersonline.com

The Problem

Generally, effluent discharged by Pakistani sugar mills contains the Oil& Grease concentrations of up to 100 - 200 mg/l; in contrast to 10 mg/llimit as defined by National Environmental Quality Standards (NEQS) ofPakistan. This problem is mainly caused due to the lubricating agentsthat are used in various machines and vessels; and that ultimately findtheir way into the wastewater when these machines and vessels arewashed. Apart from causing legal non-compliance directly, it also contributesin choking of drains and gutters along side bagasse already present inthe sugar mills effluents. Moreover, the Oil & Grease layer in the effluentchannel reduces the exposure of biodegradable components to atmosphere,resulting in higher BOD levels and automatically leading to additional costof aeration for wastewater treatment. The Oil & Grease in the effluentreduces oxygen penetration in the wastewater and ultimately hampersthe treatment efficiency of the treatment plant. This directly results inhigher capital and operation & maintenance cost of treatment plant. Theproblem is more serious when the effluent water is used for irrigationpurpose or discharged in the inland rivers where Oil & Grease chokesthe soil pores and disrupts the natural drainage process.

The ObjectiveThe objective of installation of oil skimmer in a particular industry is todecrease the quantity of oil and grease in waste water and toreduce the cost of waste water treatment plant & operation.

What is an Oil Skimmer?Oil skimmer is used to remove oil from a liquid. In some cases, oil skimmermay be used to pre-treat a fluid. In this case, it removes as much of oilas possible before more expensive and time-consuming measures areemployed.

How does it work?

Oil skimmer is an effective tool for getting oil off the top of water. It provides a never ending surface for oil tocling because of its adhesive nature. The surface is cleaned and the process is repeated on a continual basiswithout using any chemical. The process ensures recovery of a large amount of spilled product in a short span

Oil Skimmer

Belt Structure

Collected Waste Oil

Oily Wastewater

Requires minimal power lifts and separates oil from pit without the use of pump

of time. Because of its simplistic nature, an oil skimmer is easy to repair, maintain and clean.

the oil from the front side of the belt as it passes through.