Continuous biosynthesis of geranyl butyrate in a circulating fluidized bed reactor

The continuous synthesis of geranyl butyrate in organic solvent was studied. The Candida rugosa lipase(CRL) was firstly immobilized on weak-acidic macroporous cation exchange resin D151. The batch experiments indicated that the adequate acid/alcohol molar ratio was 1:1.5 and the reaction time was 3.5-4 h. Then the continuous synthesis was realized with immobilized Candida rugosa lipase in a circulating fluidized bed reactor(CFBR). A stable ester yield of 77% was achieved under optimal conditions: enzyme loading 8 g, expansion ratio 1.6, feed flow rate 0.07 ml/min and butyric acid concentration 75 mmol/l. The results provide the basis for the scale-up of the process.