Wastewater minimization using aspen water

Abstract

This thesis lays out the basic principles for analyzing a water using operation and then compares the freshwater and wastewater flowrates for a system with and without reuse. The methods of reuse, recycle and regeneration are discussed to solve the problems of multiple contaminants with multiple constraints. The preliminary mass exchange network is designed and further optimization is carried out by using ASPEN WATER software. Along with network optimizations for minimum water use, minimum network costs which include water costs or discharge costs, can also be determined with help of the software. Minimizing water use as well as the wastewater discharged from a water network are main priorities of the present work.
Two industrial case studies are discussed to illustrate the significance of wastewater minimization and the results obtained are compared with that predicted using published method. The first one is a multiple contaminants problem for a starch industry in which water saving was found to be 41% for Demineralised water and 80% for freshwater with water cost savings of about 45% and the second is a analysis of streams in petroleum refining complex in which freshwater savings was around 82%.

Key Words: Wastewater minimization, multiple contaminants, ASPEN WATER