Chapter 9: Case Studies

Provided by the International Finance Corporation

Finding a Mentor to help develop an EMS Energy Saving in Soap Production Water Savings in Sugar Refining

Process Optimization in Textile Dyeing Increased Raw Material Efficiency (Pulp/Paper)

Finding a Mentor to Help Develop an EMS

Company A, a small Brazilian firm of 'x' number of employees, had two objectives in developing its EMS. First, it sought to create cost savings to re-invest in the company and second, it wanted to comply with environmental laws.

The first step the company took was to contact a supplier company that had previously implemented an EMS of its own with positive results. The supplier company agreed to serve as a mentor, sending staff to advise and help Company A implement an EMS and achieve its environmental objectives. 

The staff from the supplier company advised Company A to prioritize its efforts by selecting areas and issues on which to concentrate, since all of the company's concerns could not be addressed at once. The staff from the supplier company also suggested that Company A examine each operational phase, such as purchasing, process, products, transportation, rework, waste and packaging, to facilitate analysis. This approach provided ideas of where to start looking for potential environmental impacts.

Company A's manager in charge of the operation worked with other employees involved in the process and identified six areas that would benefit from their resources and time. Company A also developed a "risk analysis summary" which drew on their best professional judgement to estimate the environmental hazardous risks for each of the six areas. Company A prioritized its projects and started taking measures to implement an EMS.

Six months later, the staff from the supplier company returned to Company A to help evaluate the results. They found that Company A had:

• Made great improvements with very low investment. They realized that one of the best sources of technical information were the regulators themselves and obtained assistance and support from them. For example, government agencies helped them find ways to minimize waste, since any dripping tap was a cost.
   
• Acted to reduce water consumption and monitored its progress. This action required only a small investment, which was quickly recovered in savings.  For instance, Company A purchased hose guns, which significantly reduced water waste.  It also purchased timer valves that reduced the amount of water used at one time, so that buckets of water no longer overflowed. Inexpensive individual water meters were also purchased from the water companies. Company A also started reusing its water several times before releasing it into drains, as well as detecting situations that did not require water use.
   
• Involved its staff in promoting their environmentally-friendly efforts. Employees became motivated to participate in the program and submitted ideas such as separating paper into two bins, one for waste and the other for recycled paper.  The recycled paper was turned into scrap paper, resulting in cost savings. Waste was also shredded and turned into packaging material.  Company A implemented a reward program to recognize employees who submitted ideas to minimize the company's negative environmental impacts.
   
• Bought new equipment to eliminate an obsolete process of treating material in tanks with strong chemical additives. The new equipment, which used water additives, required investments and at the first the company had rejected the possibility. However, Company A's  new environment culture prompted further consideration. The decision was made that the products used for the new process were a lot cheaper in the long run, thus justifying the investment.
   
• Identified hazardous components in their products and started removing them. For instance, platinum and palladium contacts were separated from the remaining copper and steel before it was sent for refining. Company A also began notifying the county that the hazardous material was leaving its site and being transported to the public hazardous waste incinerator. The government agency issued the firm a certificate that ensured clients and community that Company A conducts its business in an environmental responsible manner.
   
• Adopted a new purchasing policy of encouraging suppliers to take back containers of chemical substances for reuse. The company also planned to reduce the size of their vehicle engines and reorganize work patterns to reduce mileage. Those efforts would reduce CO2 in the atmosphere, creating an environmental benefit.
   
• Decided to change its packaging, requiring the cooperation of suppliers and customers. The company recognized that shrink wrapping would increase the capacity of a pallet by 40 percent and also save energy costs and transport requirements.
   
• Decided to review its arrangements with waste contractors and scrap merchants to negotiate better deals for their recycled waste. Company A also implemented an extremely rigorous control system, fully documenting every movement onto or off their site.

Company A's manager stated that the supplier company provided the advice and experience Company A needed to feel confident of putting a system in practice that would yield results and create a profit. In the manager's words, "Once you get started, you'll be surprised with your progress." The president of Company A says that the new environmental system has become part of the company's culture. Environmental issues are now considered in every decision involving capital expenditure and executives try to find the best environmental approach to take, given other constraints.

Process Optimization in Textile Dyeing

Company B, a textile hosiery processing industry in Ludhiana, India, bleaches and dyes cotton hosiery fabric on a job-order basis. Major process steps include scouring, bleaching, dyeing and finishing. The entire process is carried out using winches. After the first three steps, fabric is rinsed to remove extracted impurities and residual chemicals. After wet processing, the fabric is dried in a tubular steam hot air dryer. The company process about 4,000 kg of fabric per day, employs 150 people and has an annual turnover of about USRs700,000.

Cleaner Production Assessment

Pressure from the Pollution Control Board to comply with environmental regulations was the catalyst for a Cleaner Production program. Other factors were a high fuel consumption (compared to other industries) and a high redye rate.

Cleaner Production Solutions

A Cleaner Production (CP) assessment identified 34 options, of which 22 have been implemented, including:

• Reduction of liquor to material ratio in winches from 10:1 to 8.5:1
• Reduction of 15 percent in specific alkali consumption in scouring
• Eliminating one washing step by providing five minutes drag-out time after each discharge
• Replacing the steam hot air dryer with direct fuel-fired hot air dryer. This means a reduction of drying cost from Rs. 1,20 per kg fabric to Rs. 0.60 per kg
• Optimizing boiler efficiency by controlling draft with an additionally installed damper and fuel firing practices

Environment Benefits

Implementing 22 CP solutions resulted in the following environmental benefits:

• Reduced water consumption by 25 percent
• Reduced COD load by 20 percent
• Reduced particulate emission from 300 mg/Nm to less than 50 mg/Nm, therefore meeting air pollution norms (150 mg/Nm) without any control equipment
• Reduced redye/reprocessing rate from six to two percent, a 67 percent reduction in redyeing/reprocessing

Financial Benefits

The company invested USRs10,000 to implement 22 CP solutions, which resulted in annual savings of USRs35,000 with a payback period of less than four months. Estimated total investment and annual savings for all 34 solutions would be USRs260,000 and USRs100,000 respectively.

Energy Saving in Soap Production

Company B located in Dar es Salam, Tanzania, is a private undertaking with 45 permanent staff members and 20 seasonal employees. It manufactures five tons of bar laundry soap per hour.

The soap is made from fat through a saponification process utilizing caustic soda. After a separating process the so-called "neat soap" is taken to a crusher, where it is mixed with pigment, perfume and other additives. The soap is then transferred to an intermediate tank from which it is fed into a vacuum flash cooling system. The cooled soap is then extruded in the form of bars, cut into size and packed in cartons.

Cleaner Production Assessment

The principal source of process energy is steam, which is generated from the combustion of industrial diesel oil in the boiler furnace burners. Steam is used throughout the whole process and for handling materials (unloading of fat from truck tankers, fat storage heating). The Cleaner Production (CP) assessment revealed leakages of steam from some of the valves and inefficient use of steam. The unloading of fat delivered to the factory resulted in spillage of 3,000 kg per annum. The spilled fat was absorbed by the soil.

Cleaner Production Solutions

In an effort to conserve steam energy and curb spillage of raw material, the project team recommended the implementation of the following CP options:

• Replace leaking steam valves and traps with certified products.
• Reduce the time required for heating the fat storage tank from the initial six to seven hours to three hours.
• Incorporate the right amount of water during saponification, minimizing steam consumption during the cooling stage.
• Recover the spilled, soiled fat at the material handling section by treatment with steam, followed by separation.

Environmental Benefits

The boiler furnace consumption of industrial diesel oil was reduced by 54 percent to only 30 liters per ton of laundry soap produced, saving 415,800 liters per year. This measure also resulted in a considerable decrease in the emission CO_x, SO₂ and NO_x . The recovery of spilled fat also made a significant improvement to the direct environment of the factory.

Financial Benefits

The only option that needed some investment was the installation of steam valves, which cost USRs830. All steam saving measures together resulted in annual savings of USRs185,700. The payback time was only two days. Recovery of the spilled fat requires virtually no energy input, creating a savings of USRs2,400 per year.

Increased Raw Material Efficiency in Pulp and Paper Production

Company C in Zhejinang Province, Republic of China, produces 51,000 tons of writing paper and cardboard annually and currently employs 5,000 people. About 18,000 tons of pulp are prepared annually from wheatstraw. The major operations of the plant are pulping, which includes straw preparation, batch mode cooking, washing, screening, hypochlorite bleaching, refining, stock preparing, black liquor extraction, alkali recovery and paper making.

Cleaner Production Assessment

Company C is one of the major contributors of pollution in Zhejinang Province. It is also a major consumer of energy and water. The pulping process, which contributed mostly to the high consumption and pollution load, was selected as the focus of the assessment.

Cleaner Production Solutions

In the assessment, 38 Cleaner Production (CP) options were generated. 22 no- or low cost options were selected for implementation along with four high cost options. Options requiring a substantial investment were the introduction of a computer control system for the operation of the cooking digestor, the installation of an additional causticizer and the repair of dust collectors and the caustic dregs washer. No- and low cost options included:

• Process amendments, such as extending the temperature raising time during cooking
• Increasing the vacuum of the vacuum washer
• Changing the mesh size of the net of the washing process

The plant also decided to improve supervision of personnel and to introduce better operating procedures.

Environmental Benefits

The CP options implemented resulted in a significant decrease of the pollution load of more than 900 tons of COD on an annual basis. At the same time, the pulp yield was increased from 45 to 51 percent. The consumption of caustic soda is expected to decrease by 230 tons per year through the installation of a computer control system. Furthermore, significant water savings are being achieved.

Financial Benefits

The joint implementation of all selected no- and low cost options will result in annual savings of USRs85,000. The implementation of the medium and high cost options, requiring an investment of USRs55,000, will yield a total annual saving of USRs161,000. Payback periods range from six months to one year.

Water Savings in Sugar Refining

Company F operates two sugar refineries in Harare and Bulawayo, Zimbabwe. The Harare plant was built in 1953 and its main equipment dates back to the same period. The factory runs seven days a week, twenty-four hours a day and has a yearly production of 140,000 tons of refined sugar. The factory employs approximately 500 people.

The refineries receive raw sugar from sugar cane mills and process it into refined white sugar. White sugar is produced for the local market and for regional export. This case study follows the assessment in the Harare factory.

Cleaner Production Assessment

The focus of the Cleaner Production (CP) assessment was on water conservation, as a long drought had resulted in severe water shortage and rationing in Zimbabwe. The sugar refinery was faced with high surcharges when the water consumption level exceeded the allocated amount. The most significant sources of water loss included:

Approximately 42 m³ of fresh water used daily to wash the bagasse originating from the clarifier into the sewage system.

• An overflow of 264 m³ per day from an insufficient water storage capacity from the cooling towers, due to the increase in the capacity of the evaporation tanks.
• Use of 216 m³ of fresh water to wash the charhouse (an older method for decolorization using bone char).

Cleaner Production Solutions

The following CP solutions have been implemented:

• A water softener and additional piping were commissioned to recycle water as 'sweet water' in the melting pot at the start of process.
• The bagasse generated at the clarifiers is now put through a press filter and used for agricultural purposes, instead of being discharged into the sewage system. The water is recycled as "sweet water" in the melting pot.
• Water meters were installed to improve water management at units with high water consumption. The option of re-directing the overflow from the cooling towers to the production process is under investigation.

Environmental Benefits

The implementation of the three options is projected to reduce the water consumption by approximately 86,000 m³ annually. Solid wastes to the municipal sewer is projected to be reduced by 120 tons per year.

Financial Benefits

The factory invested USRs 28,000 for the reduction of water consumption. With an expected saving of USRs 24,000 per year on water charges, payback period will be 14 months, not considering any possible surcharges for which the company may have been responsible.