Synthesis and characterization of a catalytic membrane for pervaporation-assisted esterification reactors

Reduction of energy demand is a challenge that must be faced in coming years and process integration in chemical industry is pointed out as a feasible alternative to achieve more efficient processes. In this work, by using acetic acid and ethanol as a model system, pervaporation-assisted heterogeneous catalytic esterification was investigated to increase ester conversion in mild operational conditions. The pervaporation-assisted esterifications were carried out using Amberlyst 15 and 35 (Rohm & Haas) as catalyst and hydrophilic Pervap 1000 membrane (Sulzer) in a bench scale pervaporation apparatus. A catalytic membrane was also developed by coating the Pervap membrane with a thin superficial layer of tiny catalyst particles in poly(vinyl alcohol) solution. Reaction and separation were conducted in two separated steps and in a single one, by means of a catalytic membrane. For the former, the membrane-assisted reactor, it was observed that the ratio of membrane area to reaction volume is an important parameter to get equilibrium displacement. For the catalytic membrane there was an increase up to 60% in ethyl acetate conversion, at 60 °C. These results indicate the potentiality of the coupled process, since catalyst concentration can be easily increased, leading to higher ester production rates.