গ ণ প রজ ত ন ত র ব ল দ শ PEOPLE S REPUBLIC OF BANGLADESH PRODUCTION EFFICIENCY/ POLLUTION PREVENTION FACTORY ASSESSMENTS FOR FABRIC MILLS AND DYE HOUSES IN BANGLADESH Dhaka, 8 May 2011
Summary 1. The approach 2. The main findings 3. «Low hanging fruits» measures 4. «Best of the best» measures
1. The approach Objectives Identify measures to reduce the use of energy, water and raw materials Identify the factors that will contribute to scaling up
1. The approach Criteria 4R: Reduce, Reuse, Recycle and Recover PROCESS STAGES
1. The approach Criteria Scaling up based on economic benefits as perceived by the factory Direct benefits: savings Indirect benefits: marketing
1. The approach 1. Low hanging fruits : Feasible Cheap (< 500,000 TK) or very cheap Payback period shorter than 1 year
1. The approach 2. Medium hanging fruits Feasible Payback period higher than 1 year 3. Higher hanging fruits Needs further study Not so cheap Payback period higher than 1 year
1. The approach Methodology: 4 tasks A. Case studies of Top Performing Factories B. Assessment of five Medium-Performing Factories C. Support the implementation in one factory. D. Consolidation and final report
2. The main findings N Best Practices Class. Process stage Location Yes No WATER 1/3 2/3 W1 Eliminate water leaks in taps and pipes Low Several Upstream 5/7 2/7 W2 W3 W4 Reuse water drained out of steam condensates Low Dyeing Downstream 4/7 3/7 Minimize washing and rinsing (over flow) operations Low Several Upstream 3/7 4/7 Reuse of first wash water from solution preparation tanks Low Dyeing Downstream 0% 100% W5 Restrain hose pipe use and create a cut sample washing basin/place. Low Several Upstream 3/7 4/7 W6 Reuse cooling water Medium Several Downstream 4/7 3/7 W7 Reuse wastewater from processes in other processes that do not require high quality water. Medium Several Downstream 0% 100% W8 Fabric to water ratio to 1:6 Study Dyeing Upstream 1/7 6/7
2. The main findings N Best Practices Class. Process stage Location Yes No ENERGY 1/3 2/3 Maintain steam traps and optimized E1 steam management Low Dyeing Upstream 3/7 4/7 E2 Insulate pipe line, valves and flanges Low Dyeing Upstream 6/7 1/7 E3 E4 Optimize operation of air compressors and chilling plants Low Several Upstream 2/7 5/7 Save lightening energy using transparent roofs Low Several Upstream 2/7 5/7 E5 Use of good squeezing operation to reduce energy at drying stage Low Drying Upstream 100% 0% E6 Recovery of heat from drying operations Medium DryingDownstream 0% 100% Use of direct drying system Drying Upstream 6/7 1/7 E8 Automatic boiler blow down mechanism Study Utility area Upstream 2/7 5/7 E9 E10 E11 Recover energy from high temperature process for wash water heating Study DyeingDownstream 1/7 6/7 Recovery of heat from gas generation vent Study SeveralDownstream 1/7 6/7 Use co-generation plant instead of two separate generators plus steam boiler Study Several Upstream 0% 100%
2. The main findings N Best Practices Class. Process stage Location Yes No PRODUCTS AND CHEMICALS 1/3 2/3 C1 Reduce spillage of chemicals Low Dyeing Upstream 3/7 4/7 C2 Optimize correct temperature and volume to reduce salt, auxiliary and dye consumption. Low Dyeing Upstream 100% 0% C3 C4 Collection of surplus printing paste and using the same as black paint Low PrintingDownstream 1/1 0 Use of magnetic device for water softening Low Several Upstream 1/7 6/7 C5 Repeated reusing of caustic solution in the mercerizing operation Study MercerizingDownstream 1/2 1/2 C6 Recover of sodium sulfate Study DyeingDownstream 0% 100%
2. The main findings N Best Practices Class. Process stage Location Yes No TRANSVERSAL ISSUES 2/5 3/5 T1 Improved process control stages to avoid reprocessing, re-dyeing etc. Low Several Upstream 100% 0% T2 Improve recipe of dyes in laboratory automated / robotic dispensing system Low Laboratory Upstream 2/7 5/7 T3 Sufficient number of solution preparation vessels Medium Dyeing Upstream 5/7 2/7 T4 T5 Use dry cleanup methods like vacuum, brooms, absorbents etc. Study Drying Upstream 0% 100% Explore recovery of size in cotton processing Study MercerizingDownstream 0% 100% Total 1/3 2/3
2. The main findings Saving on water? Water is considered almost free Expensive treatment plants Savings through other sectors (energy, chemicals)
2. The main findings Saving on energy? Insolation Reuse (energy and water) Optimize
2. The main findings Saving on chemicals? Management, laboratory trials Reduce spillage Reuse
2. The main findings Metering Existing water meters? At bore wells At unit site In the machine 2/3 At bore wells 100% At unit site In the machine 2/3 Existing power meters? At gas generators site 100% At unit site In the machine At gas generators site 100% At unit site In the machine Existing gas meters? At receiving sites 100% At unit site In the machine At receiving sites 100% At unit site In the machine Starting metering can be done first at the factory level then to the unit inlets and at the end to the machine sites. Cost of water flow meter: Electromagnetic type: BDT 3,00,000-5,00,000/= Mechanical type: BDT 50,000-1,00,000/= Cost of steam flow meter: BDT 10,00,000/=
3. low hanging fruits measures «Low hanging fruits» practices Feasible Cheap (< 500,000 TK) or very cheap Payback period shorter than 1 year
3. low hanging fruits measures Measure n W1 : Eliminate water leaks in taps and pipes Sector: Water Sub-sector: Water consumption/waste water generation Present situation : There are several leakages of water from taps, valves and pipes in the factories. Machine leaks were also visible in some places. In few machines the taps over the preparation tanks were designed in a way that even after leak the leaked water was falling inside the tanks. Future situation (improved): Repair and maintain taps and pipes. Potential saving: Cost of water: Tens of thousand TK/year Cost of waste water: Tens of thousand TK/year Leakages are eliminated through leak detection measures, preventive maintenance and improved cleaning. Savings may not be lucrative but it will keep the premise clean and dry. Priority : Low hanging fruit Investment Cost: negligible Future operation cost: negligible Saving: Tens of thousand TK /year Payback period: immediate
3. low hanging fruits measures Measure n W2 : Reuse water drained out of steam condensates Sector: Sub-sector: Present situation: Water and energy Dyeing Steam is used directly as well as indirectly in the dyeing department. During indirect use, steam gets converted to water. This is pure water that still retains some heat. At several places it is collected and diverted as boiler feed water. However, not all such steam is being reused. Some of the assessed factories has implemented it and recovering 50-60% of condensate to reuse in the boiler feed. Potential saving: Cost of water: Hundreds of thousand TK/year Cost of wastewater treatment: Hundreds of thousand TK/year Future situation (improved): Collect all steam condensate and divert to boiler feed water. Priority : Low hanging fruit Investment Cost: tens of thousand TK Future operation cost: negligible Saving: Hundreds of thousand TK/year Payback period: months months
3. low hanging fruits measures Measure n W3 : Minimize washing and rinsing (overflow) operations Sector: Water Sub-sector: Wastewater management Present situation: Potential saving: In each batch process, the factory is Cost of water: doing cycles of operations including several washing and rinsing operations. As per best practice only few washes and rinses are sufficient. For medium performing factories average water used per kg of fabric (knit cotton) is 180-220 Liter; 60-100 liter of which is being used in overflow rinses only. Future situation (improved): millions TK/year Cost of waste water: millions TK/year The factory will implement a new practice where washing and rinsing cycles will be stopped once the effluent is color free. Reducing the number of cycles will reduce the water consumption. A controlled overflow rinse can reduce the water use using the existing machinery. Investment Cost: negligible Future operation cost: Negligible Saving: millions TK/year Payback period: immediate Priority : Low hanging fruit
3. low hanging fruits measures Measure n W4 : Reuse of the first wash water from solution preparation tanks Sector: Water Sub-sector: Water consumption and wastewater Present situation: Dye solution is prepared (mixed) in one dedicated vessel in the dye kitchen. Before preparing a second color solution in the vessel, the vessel is cleaned with fresh water. This water is currently treated as waste and drained to the ETP. Dye/chemical dosing tanks with the machine contains some dyes/chemical after dosing. That cleaning water is being thrown away. Future situation (improved): Dye solution will still be prepared in one dedicated vessel. However, the water used to wash the vessel in between two dye solutions will not drain to ETP, but will be taken back in the dye solution for use. The dye/chemical dosing tanks cleaning water also needs to be sent back to the machine. Savings in water may not be lucrative but will increase accuracy in the process. Priority : Low hanging fruit Potential saving: Cost of water: tens of thousand TK/year Cost of waste water: tens of thousand TK/year Investment Cost: negligible: only training Future operation cost: negligible Saving: hundreds of thousand TK/year Payback period: Immediate
3. low hanging fruits measures Measure n W5: Restrain hose pipe use and create a central cut sample washing place. Sector: Water Sub-sector: Dyeing Present situation: Potential saving: In process equipments, the water is filled in closed Cost of water: conditions and no overflow of water is taking place Tens of thousand from machines. However, water is used without TK/year any restriction with hose pipe for floor cleaning, Cost of waste water cleaning of vessels, washing of small dyes fabrics treatment: tens of etc. thousand TK/year. In each machine a tank of water is being boiled (during dyeing) for long time to use for washing cut sample to check shade/quality. Future situation (improved): Evaluate requirement of hose pipes: maybe they are not needed at all. Possibly they can altogether eliminate hose pipes. Only one wash basin in the dyeing area will serve the purpose. Priority : Low hanging fruit Investment Cost: negligible Future operation cost: negligible Saving: Total: tens of thousand TK/year Payback period: Immediate
3. low hanging fruits measures Measure n E2 : Sector: Sub-sector: Insulate steam pipes Energy Dyeing Present situation: Proper insulation can save energy. The noninsulated portion can release energy in atmosphere. Potential saving: Heat loss from un insulated portion hundred of thousand TK/year Future situation (improved): Remaining portion of pipes will be insulated. Investment Cost: Tens of thousand TK Future operation cost: Negligible Saving: hundred of thousand TK/year Payback period: months Priority : Low hanging fruit
3. low hanging fruits measures Measure n E3 : and chilling plants Sector: Sub-sector: Energy Present situation: Optimize operation of air compressors Utility section The required air pressure in the line is 3 to 4 bar, while the factory is producing the compressed air at 7 to 8 bar pressure. There is no leakage in air lines and no excess use of compressed air. Potential saving: Cost of energy: 20% of energy at air compressor could be saved. Total: hundreds of thousand TK/year Future situation (improved): Compressed air will be produced at lower pressure, saving energy. Investment Cost: Negligible Future operation cost: Negligible Saving: : hundreds of thousand TK/year Payback period: Immediate Priority : Low hanging fruit
3. low hanging fruits measures Measure n E4 : Sector: Sub-sector: Use transparent roofs Energy Electricity consumption Present situation: Tube lights in dyeing unit. Each will consume 40 watt. Potential saving: Cost of electricity in day time: Cost of :tens of thousand TK/year Future situation (improved): Replace asbestos roofs with FRP transparent roof. So during day time, tube lights will be switched off. Investment Cost: tens of thousand TK Future operation cost: Reduced Saving: tens of thousand TK/year Payback period: depending on size. Priority : Low hanging fruit
3. low hanging fruits measures Measure n C1 : Sector: Sub-sector: Reduce spillage of chemicals Chemicals Consumption of chemicals and wastewater Present situation: Sodium sulfate, soda ash and caustic soda consumption is thousands of kg per day. It is handled in bags that are brought to the dyeing area and manually transferred to the solution making tank. During the transfer some spillages take place. The chemical is eventually washed away with water coming from hose pipe and ends up into the. Potential saving: Cost of chemical spillage: tens of thousand TK/year Future situation (improved): The factory reduces spillage and washing into wastewater. Priority : Low hanging fruit Investment Cost: negligible training only Future operation cost: negligible Saving: tens of thousand TK/year Payback period: immediate
3. low hanging fruits measures Measure n C4 : Sector: Sub-sector: Use of magnetic device for soft water in boiler. Chemicals Pretreatment of water Present situation: The factory has a water softening plant. Even after the water softening treatment, however, the water still has some residual hardness. Continuous chemical dosing is done to make boiler inlet water hardness free to avoid scales in the surface of the boiler. Future situation (improved): To take care of residual hardness, a magnetic water softening device can be installed in the boiler inlet. This will keep the metal cations oriented. The device will help prevent the formation of a white calcium and magnesium carbonate scaling, and thus make sure the whole capacity of the boiler is available. The final result is an increase in efficiency and reduced frequency of boiler de-scaling. Priority : Low hanging fruit Potential saving: Hundreds of thousand TK/year Investment Cost: Hundreds of thousand Future operation cost: Reduced Saving: Hundreds of thousand TK/year Payback period: 6 to 12 months
4. "Best of the best" measures «Best of the best» practices innovative cost effective representative and replicable
4. "Best of the best" measures Measure n W8 : Increase fabric to water ratio to 1:6 Sector: Water Sub-sector: Water consumption Present situation: Fabric to water ratio is 1:8. There is scope for improvement. Modern machines allow ratio like 1:3. By using the existing machines conservation can be approached to reach close to 1:6. Future situation (improved): Smooth running of the fabric inside the machine requirements in reducing water in the vessels. Optimize processes and recipes in order to reduce water and chemicals consumption. Even if machine replacement needed, it can be thought during BMRE of the existing high water consuming machines. The benefits of W3 will be added in the potential savings to make the investment feasible. Fabric to water ratio is increased to 1:6 Priority : Medium Hanging Fruit Potential saving: Water and cost : millions TK/year Chemical cost : millions TK/year Investment Cost: millions of TK Future operation cost: Reduced Saving: Tens of millions TK/year
4. "Best of the best" measures Measure n E1 : Maintenance of steam traps (Proper steam management) Sector: Energy Sub-sector: Dyeing Present situation: The function of a steam trap is to allow the condensed Potential saving: steam in the pipe line to drain out and prevent it from Cost of steam escaping into the air. If the trap is not maintained loss: properly, steam will be lost. There are factories where Several millions at a place of the steam line valve/trap is kept open TK/year to reduce control in the steam management and to avoid jerking. Proper steam trap and steam supply management will reduce that. It is also possible to recollect that steam/steam condensate to heat up remaining raw water inlet of the boiler. Future situation (improved): Investment Cost: negligible Carry out regular maintenance of steam traps and ensure that traps are of adequate size. This will prevent the loss of steam and save water and energy. Future operation cost: negligible Saving: Several millions TK/year Payback period: immediate Priority : Low hanging fruit
4. "Best of the best" measures Measure n E8: Automatic boiler blow down mechanism Sector: Energy Sub-sector: Consumption of gas Present situation: Potential saving: Blow down operation is carried out based on a general principle. Future situation (improved): If blow down is more than required, it means that extra water is being consumed and heat is being lost. If blow down is less than required, means there will be more scale formation in boiler, more energy consumption and decreased life of boiler. Regular and appropriate blow down mechanism according to content. Measure the Total Dissolved Solids of blow down water and optimize blow down operation accordingly. This measure will help the factory either in water consumption or fuel efficiency, and increased boiler life duration. Investment Cost: Cost of meter only. If manual meter is provided, it will cost only 5000 TK, if fully automatic blow down system is installed, it will cost 100,000 TK per boiler. Future operation cost: Negligible Saving: Could be calculated only after actual measurement of level. Payback period: Require further study
4. "Best of the best" measures Measure n C4 : Sector: Sub-sector: Use of magnetic device for soft water in boiler. Chemicals Pretreatment of water Present situation: The factory has a water softening plant. Even after the water softening treatment, however, the water still has some residual hardness. Continuous chemical dosing is done to make boiler inlet water hardness free to avoid scales in the surface of the boiler. Future situation (improved): To take care of residual hardness, a magnetic water softening device can be installed in the boiler inlet. This will keep the metal cations oriented. The device will help prevent the formation of a white calcium and magnesium carbonate scaling, and thus make sure the whole capacity of the boiler is available. The final result is an increase in efficiency and reduced frequency of boiler de-scalling. Priority : Low hanging fruit Potential saving: Hundreds of thousand TK/year Investment Cost: Hundreds of thousand Future operation cost: Reduced Saving: Hundreds of thousand TK/year Payback period: 6 to 12 months
4. "Best of the best" measures Measure n C6 : Sector: Sub-sector: Present situation: Recovery of sodium sulfate Chemicals Consumption of water/quality of wastewater Present cost: Reactive dyes are used for cotton dyeing. Sodium Sulfate- popularly known as Glauber salt is used for transferring dye from solution to fiber. The entire quantity of sodium sulfate is presently going to the ETP since it is not consumed by the Fabric. This high quantity of sodium sulfate gives a relatively high Total Dissolves Solids (TDS) concentration in the effluent. To take the effluent discharge within the permissible level in terms of TDS, factories allowing diluting of the waste water as existing ETP s can not reduce TDS. Future situation (improved): Segregate dye solution containing sodium sulfate: there are technologies available to recover sodium sulfate from effluent. They are technically viable and economically feasible. The technology is based on the Multi Effect Evaporator (MEE) principle. This is the way Bangladeshi textile industries can move forward to zero discharge as it will reduce TDS (only problem of existing ETP discharge to be reused in the process) to a reusable level. Cost of sodium sulfate is 12,000 TK/ton. Present cost is tens of millions TK/year. Investment Cost: tens of millions TK. Future operation cost: Savings: Around 70% of the initial sodium sulfate cost will be recovered. tens of millions TK/year. Payback period: Payback period is estimated around two years.
4. "Best of the best" measures Measure n T1 : Sector: Sub-sector: Improve process control stages to avoid reprocessing Transversal issues Process controlling Present situation: Existing: the reprocessing is similar to the one applied in the TOP performing factories. Overall reprocessing percentage in Bangladeshi industries has reduced. But in the mid level industries still a significant improvement can be done. Future situation (improved): Mainly a combination of managerial and technical control. Quality assurance of the raw material (mainly dyes & chemical), Establishing and maintaining Right First Time (RFT) in the process and Quick Response in the management will reduce reprocessing. Potential saving: Several millions TK/year Investment Cost: negligible (staff training) Future operation cost: Saving:Several millions TK/year Priority : Low hanging fruit Payback period: immediate
4. "Best of the best" measures Measure n T2 : Sector: Sub-sector: Improve trial recipe in laboratory Transversal issues Water/chemical Present situation: Manual recipe pipetting and preparation. Efficiency is reduced and will affect the bulk production accuracy. Most of the factories has spectrophotometer for color measurement and speculating recipe. But human error during pipetting results reduced efficiency of the lab. Future situation (improved): Setting up robotic auto dispensing machine or electronic pipetting devices. Proper calibration and updating of lab equipments (spectrophotometer). These will contribute in higher laboratory efficiency and production and also it will reduce reprocessing percentage. Potential saving: Several millions TK/year Investment Cost: cost of robotic auto dispensing machine or cost of electronic pipettes. Future operation cost: very low, reduced man power needs Saving: Several millions TK/year Priority : Low hanging fruit Payback period: 1 to 2 years
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