Why it pays to be clean.
National Cleaner Production Centres (NCPCs) set up jointly by UNIDO and The United Nations Environmental Programme (UNEP) have assisted companies to rationalise their production processes and save money on raw materials, energy, water and waste treatment. Over the last four years, some 200 enterprises in 15 countries have successfully implemented cleaner production options with the advice of their NCPCs.
NCPC staff are highly qualified nationals who have worked in, or with industry for many years. They are familiar with the problems and the challenges industry faces every day. The staff have been trained in the country and abroad in the identification of resource and material saving opportunities. They have access to UNIDO's technical expertise and to UNEP's experience in policy and information dissemination. The NCPCs also draw on a UNIDO/UNEP pool of institutes in Europe and the United States that specialise in cleaner production.
NCPCs have thus become national centres of excellence for cleaner production in their countries. They offer six basic services: awareness raising; on-site cleaner production assessments; training on cleaner production and related issues; assistance to companies in obtaining investment funds for cleaner technologies; dissemination of technical information on cleaner production; advice to decision-makers on policies to encourage cleaner production.
Acting as focal points for cleaner production, NCPCs extend the global network to partners in their countries - such as productivity councils, certified engineers' associations, chambers of commerce, universities, etc. Clearly, this extensive network, with its wealth of information and expertise, allows the NCPCs to provide much better services to companies.
International donors like ILO, NORAD, USAID, and the World Bank have identified NCPCs as highly competent partners for cleaner production activities. Many organisations in developing countries and economies in transition recognise the strength of the programme and have requested to be included. As the enthusiasm is shared by donors, the NCPC programme expects to expand its network to 20 centres in the coming years.
Case study 1:
The objective in this case was produce energy savings in the soap production of Shivji and Sons Ltd. in Dar es Salaam, Tanzania. The company is a private undertaking and has a rated capacity of five tonnes of soap bars per hour. The company has 45 permanent staff members and 20 seasonal employees.
The soap is made from fat through a saponification process that utilises 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 flask cooling system. The cooled soap is then extruded in the form of bars, cut into size and packed in cartons.
The principal source of energy is steam, which is generated by burning industrial diesel oil in furnace burners. Steam is used throughout the whole process and for materials handling.
Cleaner Production Assessment
The company asked the Cleaner Production Centre in Tanzania to undertake a cleaner production assessment of its industrial operations. The assessment brought to light two major findings. First, there were significant leakages of steam from some of the valves and generally an inefficient use of energy. Second, the unloading of fat delivered to the factory resulted in spillage of 3,000kg 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 cleaner production options: Replace leaking steam valves and traps with certified products. It also reduced the time required for heating the fat storage tank from the initial 6-7 hours to three hours. It advocated incorporating the right amount of water during saponification, minimising steam consumption during the cooling stage; and the recovery of the spilled, soiled fat at the material handling section by treatment with steam, followed by separation.
By implementing the proposed cleaner production options, the company reduced its boiler furnace consumption of industrial diesel oil by 54% to only 30 litres per tonne of laundry soap produced, saving 415,800 litres per year. This measure also resulted in a considerable decrease in the emissions of CO, CO2, SO2 and NOx. The recovery of spilled fat also made a significant improvement to the direct environment of the factory.
The only option that needed some investment was the installation of steam valves, costing $830. All steam saving measures together resulted in annual savings of $185,700. The pay-back time was only two days. Recovery of the spilled fat required virtually no energy input, realising a saving of $2,400 per year.
Case study 2:
Water saving in sugar refining at the Zimbabwe Sugar Refining Corporation which operates two sugar refineries in Harare and Bulawayo. 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 which was established in 1953. The 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 tonnes of refined sugar. The factory employs approximately 500 people.
Cleaner Production Assessment
At the request of the company, the Zimbabwe Cleaner Production Centre undertook an assessment of the Harare site. The focus of the 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.
From the assessment it became clear that the most significant sources of water loss included the following: approximately 42cum of fresh water was used daily to wash the bagasse originating from the clarifier into the sewage system.
There was an overflow of 26cum per day from insufficient water storage capacity from the cooling towers; 216cum of fresh water was used to wash the charhouse (an older method for decolourisation using bone char).
Cleaner Production Solutions
The following cleaner production solutions were proposed and 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. Water meters were installed to improve water management at units with high water consumption. A further option to re-direct the overflow from the cooling towers to the production process was slated for further investigation.
The implementation of the three options reduced the water consumption by approximately 86,000cum annually. As a side benefit, discharge of solid wastes to the municipal sewer was reduced by 120 tonnes per year.
The factory invested $28,000 for the reduction of water consumption. With expected savings of $24,000 per year on water charges (not considering any possible surcharges for which they might have been responsible), the pay-back period was 14 months
More Cleaner Production activities are planned in Brazil, China, India, Mexico, Nicaragua, Tanzania, Tunisia, Vietnam, Zimbabwe and new centres are being established in Croatia, Ethiopia and Morocco.
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|Title Annotation:||environmentally friendly production methods|
|Article Type:||Cover Story|
|Date:||Nov 1, 1999|
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