Integration of quality-dependent prices in the optimization strategy for chemicals ultrapurification by reverse osmosis membrane cascades

Abstract

The present work is focused on the optimization of multistage reverse osmosis membrane cascades applied to the ultrapurification of chemicals for the semiconductor industry (hydrogen peroxide was chosen as case study). This paper is a part of the author's overall work on the subject. The novelty of this paper is the introduction of a price-dependent model for the product quality that can be adjusted between customer and producer. The membrane systems were formulated with product quality-dependent price resulting a nonlinear programming problem. The optimal number of stages included in a cascade was strongly dependent of the desired product quality while the formulated quality-dependent price model determined the target purity. Five quality-dependent price fittings were used to illustrate the case study: linear, parabolic, exponential, sigmoidal, and bisigmoidal relationships between product quality and price. For the sigmoidal and bisigmoidal fittings, least operation conditions can afford revenues similar to ones under linear, parabolic, or exponential models, but with lower costs.