Optimization of combined heat and mass exchanger networks using pinch technology

Abstract

AbstractThis article examines the benefits that may be obtained by combining the optimisation of heat and mass exchanger networks. This study uses a Pinch Technology approach to the targeting of Combined Heat and Mass Exchanger Networks (CHAMENs), and illustrates it with application to three examples. The first example has just one external mass separating agent (MSA), the second has both process and external MSAs, and the third is an extension of the second with a heat exchanger network integrated. The major benefits arise when it is possible to cool the process MSA with an excess capacity to remove mass. This reduces the flowrate of the external MSA (since this exists below the pinch) and can even do away entirely with the need for it. This also leads to a reduction in the capital cost requirements of both the process and the external MSAs, as well as a reduction in regeneration costs. The implication of this is that a limitation to the use of the available capacity of process MSAs is their mass exchange temperature. It was also found (in the example in which hot/cold utilities are used to enhance mass exchange) that the mass exchanger network synthesis (MENS) costs generally dominate over the heat exchanger network synthesis (HENS) costs. Other examples presented in this article support these conclusions. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.