A novel process of lipase-mediated biodiesel production by the introduction of dimethyl carbonate

The combination of free lipase and immobilized lipase could catalyze biodiesel production effectively. However, some additional process, like water washing, is required to remove the remaining traces of glycerol from the crude biodiesel product. This work presents a novel process by introducing dimethyl carbonate (DMC) into the system, where lipase -catalyzed transesterification between DMC and glycerol occurs, leading to the on-line removal of glycerol. With dimethyl carbonate introduced in the lipase -catalyzed biodiesel production process, the glycerol concentration and acid value decreased to 0.06% and 0.5 mg KOH/g oil from the original values of 0.4% and 1.8 mg KOH/g oil, respectively. This process has been investigated in an air-lift loop reactor with very good results.