Cogeneration of electricity and heat in industry

The overview was prepared for the United Nations Environment Plogramme (UNEP). It represents one of the five parts forming UNEP's comprehensive study on cogeneration of electricity and heat in developing countries. The other parts of the study deal with cogeneration in district heating and cooling, cogeneration in fresh water production and other applications of waste heat. The publication consists of a short revision of the principle of cogeneration cycles, which in spite of their tremendous potential for energy conservation and environment protection, are still almost unknown to the majority of developing countries. It is followed by selected examples of modern utilization of cogeneration in industry. These are given in some detail with emphasis on the industries of particular interest to developing countries. The use of alternative fuels in cogeneration, particularly non-commercial fuels, like rice hull, wood and agricultural wastes, slurry, etc., is of particular importance in developing countries. For this reason examples of most recent applications of cogeneration using alternative fuels are discussed. This is followed by consideration of the economic and social aspects of cogeneration. Finally, a few conclusions and general guiding steps suggested for developing countries interested in cogeneration are given.