Wastewater Minimization of Batch Processes with Single Contaminant
This paper presents a novel method based on mixed integer linear programming (MILP) that addresses the optimization of water network in batch chemical processes with single contaminant to minimize wastewater discharge. In this method, a batch cycle is divided into several time intervals and a unit would be divided into several sub-units, if necessary. It ensures that each unit/sub-unit operates in only one time interval. Each unit/sub-unit is attached with a buffer tank to relax the time constraint. The sequence of units is pre-determined in ascending order of their outlet concentration, so that units and their buffer tanks only provide water to afterward units. A superstructure of units, buffer tanks, and water-using connections is developed. The corresponding mathematical model is a MILP problem that guarantees the global optimum and obtains a solution quickly. Heuristic rules are used to analyze and omit the redundant buffer tanks. The proposed method is applied to a case study in this paper. The results show that the method is effective.
Zhong Cao, Xueqiang Cao, Lixian Sun, Yinghe He
H. N. Cheng et al., "Wastewater Minimization of Batch Processes with Single Contaminant", Advanced Materials Research, Vols. 239-242, pp. 2214-2219, 2011