A new graphical targeting method for water minimisation

This paper presents a new graphical method for targeting fresh water and wastewater minimisation. The new approach is based upon a new representation of water composite curves and the concept of water surplus. This is used to construct a water surplus diagram, which is similar to the grand composite curve in heat pinch analysis. The method has several advantages over existing techniques, such as being able to deal with a wider range of water-using operations as well as having more convenient and familiar representations. Also, the targets are unique and are not dependent on any assumed mixing arrangement. The paper briefly discusses network design and also considers two areas (process modifications and water regeneration) where the insights obtained from the graphical tools are most valuable. (C) 2002 Elsevier Science Ltd. All rights reserved.