WASTE-WATER MINIMIZATION OF INDUSTRIAL-SYSTEMS USING AN INTEGRATED APPROACH

The design of an industrial water system, which makes the most efficie nt use of the water resources available, is a complex problem that inv olves different trade-offs. If we assume that no fundamental process c hanges can be performed (i.e. wet cooling towers cannot be replaced by air-coolers, etc.), then we can improve the efficiency of the water s ystem through practices as water re-use, regeneration of water prior t o re-use, or regeneration and recycling. The inherent combinatorial na ture of the problem calls for the development of a systematic methodol ogy that can deal with the high dimensionality of the design problem. In this paper we propose an integrated methodology for the design of i ndustrial water systems. This approach brings the engineering insights provided by the water-pinch analysis together with powerful mathemati cal programming tools. The method is based on a decomposition scheme f or the optimisation of a superstructure model that includes all the po ssible features of a design. The proposed decomposition strategy is ba sed on a recursive procedure. With this new approach, a network featur ing minimum total annualised cost can be found where the complexity of the network structure is under the control of the designer and many p ractical constraints can be incorporated. (C) 1998 Elsevier Science Lt d. All rights reserved.