Improvements for mass-exchange networks design

This paper addresses minimum utility cost mass-exchange network design by c onsidering the special case of water minimisation. Two different situations are considered, re-use and regeneration re-use for single contaminants. Fo r re-use, three different methods of targeting are presented, one of them b eing simultaneously a design method. This novel design method has the advan tage of considering flowrate constraints only in the final stage of design. The concept of multiple pinches is introduced to prevent designing network s that do not lead to minimum cost distributed effluent treatment systems. For regeneration re-use, this paper presents the first known algorithm for targeting minimum water consumption in all possible situations. The targete d flowrate is then used to design the mass-exchange network, that almost al ways features splitting of operations. (C) 1999 Elsevier Science Ltd. All r ights reserved.