AEI-type zeolite membrane for dehydration was prepared, and a flow-type membrane reactor for the esterification of acetic acid and ethanol by AEI membrane was developed. A synthesized AEI membrane had suitable molecular sieving property for gas separation (H2/i-butane and CO2/CH4) and pervaporation (H2O/acetic acid). AEI membrane showed H2O permeance of 6.2 × 10−7 mol m−2 s−1 Pa−1 with a separation factor of 67 at 363 K for the equimolar mixture of H2O/acetic acid. AEI membrane maintained stable performance under acidic conditions. The yield of ethyl acetate at 363 K in a flow-type membrane reactor with AEI membrane successfully exceeded the equilibrium of 69.1%, reaching 89.0%. The flow rate of feed solution strongly affected the conversion of acetic acid and the space–time yield (STY) of ethyl acetate. Due to the more significant proportion of water selectively removed from the reaction system at a lower feed flow rate, the thermodynamic equilibrium shifted significantly, resulting in higher conversions. In contrast, STY increased with increasing feed flow rate. Our flow-type membrane reactor exhibited a relatively large STY of 430 kg m−3 h−1 compared with the batch-type membrane reactor previously reported.

Continuous-flow reactors used for manufacturing pharmaceuticals and fine chemicals have been investigated because of their advantages of high space−time yield, heat efficiency, mixing efficiency, and selectivity. In this study, we developed a flow-type membrane reactor to perform transesterification, one of the important reactions in synthesizing pharmaceuticals and fine chemicals. We observed that anion exchange ionomer (AEI) membrane exhibited high methanol selectivity because of the molecular sieving effect from the reaction system of transesterification of methyl acetate and i-butyl alcohol. Because the equilibrium level of conversion is shifted by the selective removal of methanol, the yield of i-butyl acetate using the flow membrane reactor with the AEI membrane reached 66.2%, which exceeded the 42.9% level of the equilibrium conversion without membrane. The productivity of ester improved by 54% using the proposed membrane reactor. The flow-type membrane reactor exhibited stable performance for at least 9 h. The effect of residence time in a flow reactor on the yield of ester was also studied. A substantial amount of methanol is removed through the membrane by extending the residence time. A high methanol removal fraction leads to a substantial shift in the equilibrium level, thereby improving the product yield.