A Superstructure Based Optimisation Framework for Batch Water Network Synthesis with Multiple Wastewater Treatment Models

Abstract

The existence of numerous water treatment/regeneration technologies capable of increasing the reuse opportunities for water–using network of batch processes calls for a systematic methodology to choose between them. Hence, this article aims to propose a new framework for the synthesis of total water network in batch plants when varieties of treatment units are available. First, a state space superstructure incorporating all feasible configurations for water reuse, recycle and treatment is proposed, which also accounts for the selection of different wastewater treatment technologies. Then, a mixed-integer nonlinear programming (MINLP) model embedded with the scheduling formulation of treatment subsystemis formulated based on the proposed superstructure. Furthermore, trade-off between treatment cost and fresh water consumptionis also taken into consideration in the formulation. In addition, five rules are developed in the pre-processing procedure to eliminate redundant water treatment technologies to simplify the topological structure of the synthesis problem. Two cases are presented to compare different categories of treatment units in total water network and demonstrate the effectiveness of the proposed methodology.