Acid-Base Reactions Enhancing Membrane Separation: Model Development and Implementation

C. Bayer[1], S. Stiefel[1], M. Follmann[1], and T. Melin[1]

[1]AVT Chemical Process Engineering, RWTH Aachen University, Aachen, Germany

Reactive extraction of organic acids from an aqueous solution to an alkaline stripping fluid is based on a selective barrier allowing permeation of non-polar molecules, which subsequently react with the stripping agent. The shift from the organic acid to its base induced by the chemical equilibrium enhances mass transfer inside the membrane’s porous substructure. A model of the porous layer of the membrane is implemented with the COMSOL Multiphysics® Chemical Engineering Module, whose equation system is modified to account for instantaneous equilibrium reactions. The results are compared to an analytical solution.

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