The influence of hydrodynamic conditions on the recovery of acetone, butanol and ethanol in pervaporation membrane modules

In order to assess the influence of hydrodynamic effects on the recovery of n-butanol by means of pervaporation, a commercial PERVAP 4060 membrane was investigated. Laboratory pervaporation experiments were carried out providing a comparison of the permeation fluxes and enrichment factors. While the enrichment factors achieved in both modules under the same process conditions were comparable, the permeation fluxes differed from each other. In order to explain the observed differences, hydrodynamic conditions in the membrane module were examined by means of CFD simulation performed with ANSYS Fluent 14.5 software. Two different modules having membrane diameters of 80 mm and 150 mm were analyzed. As a result, different velocity profiles were obtained, which served to estimate the mass transfer coefficients of butanol, ethanol and acetone.