Improvement of Isopropyl Propionate Esterification Reaction using a Vapor Permeation Membrane Reactor

In this study, a vapor permeation-integrated heterogeneous catalytic esterification reaction was investigated to improve the ester conversion of propionic acid and isopropanol. The reaction was carried out using Amberlyst 15 (Rohm Haas) as a catalyst with different weight fractions of 3%, 4%, 10%, and 12% wt. relative to propionic acid. A hydrophilic PERVAP®2201 membrane (Sulzer) was used to remove water vapor from the glass reactor. Different molar ratios (1:1, 1.5:1, and 3:1) of alcohol to acid were used in the feed mixture. Applying the coupled membrane system, using 12wt.% of catalyst, increased the acid conversion from 39% (when no membrane was employed) to nearly 90% for three hours after the beginning of the process.