STEPS TAKEN TO IMPROVE ENVIRONMENTAL PRACTICES AT THE APPLETON SUGAR FACTORY Delroy Dunkley and Fayona Lewis
Abstract The impact of factory operations on the environment is of major concern the sugar Industry, in particular Appleton Estate Steps have been taken to minimize the negative impact on the environment in the areas of water, air and noise pollution.
Abstract cont d It is intended d that the estate will become compliant with the established Environmental Code of Practice for Jamaica s Sugarcane Industry and by extension with the standards of the National Environmental and Planning Agency. This paper highlights the steps already taken and the plans to be implemented to achieve the stated objectives
Introduction The negative impact of industrial i operations on the environment has been of major concern for many years. The level of concern has increased over time as damage to the environment has become more visible There is increased knowledge relating to the cause and effect of damage to the environment.
Introduction With the identification of these causes comes the development of solutions or codes of practice needed to minimize or eliminate these effects. There is the need to improve the efficiency of factory operations thus minimizing cost and improving profitability.
Introduction Coupled with this is the need to preserve the environment by minimizing or eliminating pollution. Appleton Sugar factory is located very close the Black River, which makes improving our environmental practices even more critical. These measures are presented under the headings outlined for the Section 2 of the Environmental Code of Practice for the Sugar Cane Industry
Sugar Cane Testing The use of octapol which is a more environmentally friendly chemical (recommended by SIRI) has been in use since the 2001/2002 crop. This has allowed for easier disposal of waste material. The recycling of sample bags has reduced the bulk of solid waste to be disposed of. Solid waste, mainly bagasse, is stored in a concrete bin for containment. It is removed daily to the designated area on the estate for disposal.
Cane Yard Management Sugar cane is stored over short periods as proper planning is done to ensure that only the estimated cane to be crushed in one day is prepared and delivered to the factory.
Cane Yard Management cont d The use of side tipping trailers for the transportation of chopped stick cane and its direct offloading on to the washing plant has significantly reduced spillage
Cane Yard Management cont d Dialogue with haulage contractors to prevent overloading of trucks/carts has also helped in this area Spillage of raw material on the roads represents loss of revenue to both farmers and contractors.
Cane Yard Management cont d Spilt canes are gathered and reused immediately thus preventing it from becoming a part of the solid waste stream In the event that the storage area becomes empty, all debris and dirt is removed from the area and disposed of in the designated area on the estate
Cane Preparation Washing The washing plant is set at a 45 degrees angle which allows minimum volume of water for removal of debris from the cane. Washing Plant
Cane Preparation cont d Attempt has been made to avoid the washing of canes and some success has been gained in this area. The discharge of wash water with high sediment level into the nearby river was a major concern
Out of this concern drain separation was done. Washwater pumps CANE YARD Evap condenser sealing well G blind OC filter sealing well Continuous V/pans sealing well Condenser discharge drain F Oil trap E ills mi D C B Lime tank Mixed juice tank Clarifier A blind H Batch pans sealing well Evap washout blind Sugar lab To M.J. tank Vertical crystallizer S/lab sewer tank Mud tank blind J #2 boiler I Fugal station
Cane Preparation cont d All the factory drains were modified to allow waste water from other sections of the factory to be transferred to these ponds.
Cane Preparation cont d Settling ponds for cane wash and other high sediment level waste water were also constructed.
Cane Preparation cont d The settling pond arrangement consists of a series of five ponds which serves as a holding area. This allows sufficient sedimentation time prior to its discharge into the water course. At the outset we were plagued with foul odor from the ponds
Aerators were fitted to minimize the activity of y anaerobic bacteria thereby decreasing air pollution.
Cane Preparation cont d White lime was also used to counter bacteria and odor. The idea to pass the cane wash water over partially burnt bagasse from the boiler scrubber to decolorize and deodorize met limited success
Milling Milling train is washed twice per shift as standard practice. Mills are sanitized to prevent bacterial growth. Effluent from washing of floors passes through an oil trap before it is discharged into the settling ponds.
Oil Trap Outline
Process House Operations Filter Mud Disposal Construction of a 40ton capacity bin allows for ease of loading. Continuous removal of mud prevents pile-up Concrete barriers provide containment area for mud in case of spillage. Mud is stored in holding area during rainy periods.
Process House Operations Liquidation of Clarifier Waste liquidating material is sent via the transfer pumps to the settling ponds where it is cooled and settled before discharge with the rest of the streams.
Process House Operations Lime Receipt and Storage Relocation and improvement of lime receipt and storage area is being done in an effort to reduce dust nuisance The area is structured to improve the safety of personnel Relocation will allow spilt material to enter drain network en-route to settling ponds.
Process House Operations Entrainment to Condensers C CVP was fitted with an entrainment dome at the start of the 2006/07 to prevent carryover Anti foam is also used in the vessels to reduce carryover. Monitoring of pans is a priority especially for Process House personnel
Process House Operations Evaporator Cleaning As per the code (section 2-6) the spent caustic is returned to the holding tank and new caustic added until the desired concentration is achieved. The slurry that forms at the bottom of the tank is diluted before it is disposed of. The caustic soda storage area is bunded.
Process House Operations Spill Control All crystallizers are fitted with level controllers that can detect above normal levels in the crystallizers. The levels of these tanks can be monitored from the computer system by a Control Room Operator.
Process House Operations Spill Control The computer system is equipped with an alarm which indicates to operators when these levels have been reached. An attendant is assigned to periodically monitor the levels in the event that the level controllers malfunction.
Process House Operations Centrifugals Enclosed design of continuous high grade centrifugal significantly reduces spillages The sugar from the centrifugal passes to a dryer via screw conveyors which are enclosed to avoid spillage and contamination.
Process House Operations Centrifugals The dryer is equipped with a scrubber which catches all sugar dust which is then sent back to process En route to storage sugar travels on an enclosed belt conveyor thus preventing spillage. Sugar is stored in a leak proof metal bin.
Process House Operations Product Handling The facility is available however for spilt material to renter the system for reboiling. All the persons who handle the product are required to have a food handler s permit which is renewed annually, usually at the start of the crop.
Boiler Operations During crop steam is supplied by a 220,000lbs/hr bagasse fired boiler which has resulted in significant reduction in the use of fossil fuel. The production of sulphur oxides and nitrous oxides is also significantly reduced.
Boiler Operations cont d The boiler is equipped with hoppers to remove the coarse ash and grit. The flue gas passes through a cyclonic wet gas scrubber, which enables the stack emissions to be free of particles Boiler Stack Emission
Boiler Operations cont d The collected ash is sluiced into a concrete trough, channeled to a sump and pumped to a series of settling ponds where the clean overflow discharges into the river. The ash ponds are cleaned periodically and at the end of crop and the ash used as soil conditioner.
Boiler Operations cont d The design of the Bagasse Fired Boiler enables bagasse of high ash content (dirty) to be burnt quite efficiently The washing of cane can be significantly reduced or eliminated, thus easing the problem of disposal of cane-wash water and its consequent impact on the environment.
Boiler Operations cont d An oil trap was also constructed for the oil fired boilers to capture any spillage of fuel. To reduce noise a new exhaust steam valve equipped with silencer is being installed for the start of the next crop.
To eliminate the problem of bagasse being a dust nuisance a 1000 tonne bagasse bin was constructed.
Boiler Operations cont d The bin is totally enclosed and the bagasse travels via covered conveyor belts to and from the bin.
Boiler Operations cont d Bagacillo is dispensed to screw conveyors via chutes to reduce dust nuisance caused by these particles becoming air borne. Transition points between een conveyors ors remain sources of dust nuisance to be overcome. Bagacillo Chute and Screw Bagacillo Chute and Screw Conveyor
Power House A control room for the power house has been constructed with sound proof material which has significantly reduced the noise level in the switchboard area. The diesel exhaust piping has been thermally insulated which, in addition to heat reduction has reduced the noise level to approximately 100 decibels
Power House cont d Plans are in place to have the silencers for mufflers relocated closer to the units to further reduce noise level to the recommended 65 decibels.
Power House cont d Waste oil from the diesel generators is recollected in metal drums and used by haulage contractors in their hydraulic systems. Plans are being made to have this oil recycled to the Bunker C oil tank.
Process Effluent Treatment and Disposal In April 2006 water samples were taken from the river at the inlet of the first pond the outlet of the last pond. Analyses were done on each sample The results were compared with those of samples taken within the same month in 2005 at the same sample points
Process Effluent Treatment and Disposal The results show that the ponds have improved the treatment process of waste water and most of the parameters are in compliance with NEPA Standards. Chemical Oxygen Demand (COD) between intake to the first pond and outlet from the second pond was reduced by 77.29%.
Process Effluent Treatment and Disposal There was a decrease in Total Suspended Solids (TSS) of 66.18%. Other results were as follows: Nitrate reduced by 86% Phosphate reduced by 99.6% Total Dissolved Solids reduced by 66.18%. All these are below the NEPA standards in addition to sulfates, oil and grease.
General Old metal is sold to scrap metal dealers thus preventing the pile up of metal at the factory. All personnel are provided with protective and safety equipment. Safety audits are conducted periodically to ensure compliance to the required standards.
Conclusion This is the first year of operation for the settling ponds and as such improvement work is continuing.
Conclusion The following improvement methods are being looked at: the use of elbows on the connecting pipes to reduce the flow rate of the water between ponds. Chlorination of the waste water before the final pond and allowing sufficient contact time before discharge into the river. The use of two additional ponds and the use of water hyacinth to reduce TSS and in turn reduce COD.
Acknowledgements The Management of J. Wray & Nephew, Appleton Estate for granting permission for this presentation to be made. Mr. Everett Williams for his assistance with data. Messrs. Richard dbryan and ddelroy Foster for their advice and assistance in editing. Thanks to all other individuals who have assisted indirectly in the completion of this presentation.
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