Multiobjective Optimization Applied to the Integration of Polyamide and Cellulose Acetate Reverse Osmosis Membranes in Hybrid Cascades for Ultrapurification of Wet Chemicals

Abstract

The present work is focused on three main aims. The first one is the comparison of commercial polyamide (BE from Woongjin Chemical) and cellulose acetate (CE from GE Osmonics) reverse osmosis membranes when applied to the ultrapurification of aqueous hydrogen peroxide solutions. The second one is the search for possible advantages of combination of both types of membranes, which show quite different characteristics, under a hybrid cascade configuration. The results demonstrated that the employment of only polyamide membrane cascades is more competitive than hybrid systems for this application. The third one is the analysis of the influence of the product quality over the optimal economic cascades. The polyamide membrane systems were then formulated adding product quality metrics to economic criteria to afford a bicriteria nonlinear programming (NLP) problem. The Pareto solutions to the multiobjective problem were generated via the epsilon constraint method. On the one hand, maximum economic profit solutions corresponded with the configurations applying bypass. On the other hand, maximum quality solutions were obtained by low recovery rates (specifically in the last stages of the cascade).