Gas-phase enzyme catalysis using immobilized lipase for ester production

Bench-scale reactors were operated in continuous recycle and single-pass modes using immobilized porcine lipase to catalyze gas-phase esterification of ethyl alcohol with two carboxylic acids (acetic acid and propionic acid). Approximately one order of magnitude increases (over uncatalyzed reactions) in conversion were achieved; produc-tion concentrations ranged from 0.1 to 0.5 mM in air, and were affected strongly by substrate concentration and acid-induced enzyme inactivation.