Preparation of Amberlyst-coated pervaporation membranes and their application in the esterification of acetic acid and butanol

Catalytic Amberlyst 15 layers have been deposited on composite ceramic/poly(vinyl)alcohol membranes by the dip-coat technique using Aculyn^® as a rheology modifier. Tuning of the catalytic layer thickness is possible by varying the number of dip-coat steps. The obtained "dried-mud like" Amberlyst 15 layers are stable during pervaporation and reaction experiments. The catalytic activity of the Amberlyst-coated pervaporation membrane equals the activity of the unsupported catalyst. In the pervaporation-assisted esterification reaction between acetic acid and 1-butanol the catalytic membrane is able to couple catalytic activity and water removal. Due to the high activity of the Amberlyst catalyst the conversion of the esterification reaction is limited by the removal rate of water through the membrane. This is in contrast to zeolite-coated pervaporation membranes, for which the conversion of the esterification reaction between acetic acid and 1-butanol is limited by the catalytic activity.