Extension of pinch analysis to targeting and synthesis of water recycling networks with multiple contaminants

Abstract

An extended targeting and synthesis procedure using the Pinch approach has been developed for material resource conservation networks with multiple contaminants (e.g. water recycling network with multiple constraints). The Sink and Source Composite Curves (CC) are constructed for each contaminant (load vs flowrate). In this work, a 'polygon' rule is introduced for the CCs representation that illustrates the feasibility of the source mixing. The Source CCs for all the contaminants have to be shifted at least until a 'polygon' is formed around the vertices of the Sink CCs, with lines represent the edges of the Source and Sink CCs. The framework first identifies a freshwater target for each sink with Pinch Analysis based on the pre-determined source arrangement. A condition for further reduction of the freshwater is then checked with the proposed algorithm. Pinch Analysis of each sink sequentially enables the freshwater target and the optimal network design with allocated sources flowrates to be determined.