The optimal production conditions of biodiesel by transesterification of waste clay oil and methanol catalyzed by enzyme were studied.The catalysis effects of equal dosage of two enzymes(Lipozyme TL IM and Novozyme 435)were compared,and Lipozyme TL IM was screened as the suitable catalyst. With molar ratio of methanol to oil, enzyme dosage, reaction temperature and reaction time as independent variables, biodiesel yield as response value, the production of biodiesel from waste clay oil catalyzed by enzyme was optimized by response surface methodology. The results showed that the optimal transesterification conditions were obtained as follows: molar ratio of methanol to oil 4∶1, Lipozyme TL IM dosage 10%( based on the mass of waste clay oil ), reaction temperature 35℃and reaction time 15 h;under these conditions, the biodiesel yield was 95.9%,and the quality of the biodiesel was very close to the quality standard of 0# diesel. |