Heat recovery in distillation by means of absorption heat pumps and heat transformers

The integration of absorption heat pumps and transformers in distillation processes is considered. Single-stage and two-stage devices of different configuration are compared on the basis of a simplified evaluation of the operating costs (in terms of a steam-saving factor, SSF) and of the fixed costs (in terms of heat-storage capacity, HSC). The major parameters affecting the results are the operating temperature and the ratio between the cold and hot utilities of the distillation column. In general, it appears that each examined configuration represents the optimal choice for a different distillation problem. Nevertheless, the parallel heat pump-transformer allows one to exactly match the heat loads of most distillation processes and to minimize the environmental impact. Copyright (C) 1996 Elsevier Science Ltd.