Opportunities for heat exchanger applications in environmental systems

There is a worldwide interest in using pollution prevention methods to elim inate or lessen air, water, land and thermal pollution problems. Pollution prevention is designing processes that do not create pollution in the first place. Heat exchangers play an essential role in pollution prevention and in the reduction of environmental impact of industrial processes, by reduci ng energy consumption or recovering energy from processes in which they are used. They are used: (1) in pollution prevention or control systems that d ecrease volatile organic compounds (VOCs) and other air pollutant emissions ; (2) in systems that decrease pollutants in wastewater discharges, the amo unt of the discharge and thermal pollution; and (3) used to recover energy in facilities that incinerate municipal solid waste and selected industrial hazardous wastes. Heat exchangers are also used in the heating, cooling an d concentration of process streams that are part of many other pollution pr evention or control related processes. In this paper, first presented is ba ckground information on the role of heat exchangers, their types, and a dis cussion of environment pollution problems. Next, the role of heat exchanger s is outlined in the prevention and mitigation of the following pollution p roblems: air pollution from VOCs, sulphur oxides (SOx), nitrogen oxides (NO x); water pollution from industrial processes, thermal pollution, and land pollution resulting from municipal solid wastes or industrial hazardous was tes. Specific Research and Development needs for environmental heat exchang ers are then summarized in the paper. It is hoped that this paper will chal lenge the heat transfer engineering community to further enhance the role o f heat exchangers for pollution prevention and global sustainable developme nt. (C) 2000 Elsevier Science Ltd. All rights reserved.