Batch and continuous production of biodiesel catalyzed by lipase immobilized PVDF membrane - optimization and kinetic study

• Main Authors: Li-Ting Peng, 彭俐婷
• Other Authors: Yung-Chuan Liu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/28065927129931087373

碩士 === 國立中興大學 === 化學工程學系所 === 101 === In this study, the Candida rugosa lipase was immobilized onto Polyvinylidene fluoride film. It has good transesterification activity and can be used for biodiesel production. At first, polyvinylidene fluoride (PVDF) membrane was grafted with 1,4-diaminobutane and activated by glutaraldehyde for C. rugosa lipase immobilization. The lipase-immobilized membrane was used for producing biodiesel from soybean oil and methanol in batch reactor via transesterification. Response Surface Methodology (RSM) in combination with a 5-level-5-factor central composite rotatable design (CCRD) was employed to evaluate the effects of variables on the synthesis of fatty acid methyl ester (FAME). By ridge max analysis, the predicted yields was 97%, and the optimum reaction conditions were 33h, 40℃, 4.5 pieces of lipase-immobilized membrane, 4:1 substrate molar ratio and 5.2% water content. The verification experimental performed at the optimal conditions obtained a yield of 95.3%. The lipase-immobilized PVDF membrane showed good reuse ability for biodiesel production, enabling operation for at least 165 h ( five reuses ) of the batch operation without significant loss of activity. A continuous system for FAME synthesis was developed. Response Surface Methodology (RSM) based on 5-level-2-factor central composite design (CCD) was used to optimize the two important reaction variables (substrate flow and membrane height) on the yield. The optimal conditions were set as follows : 0.13 ml/min substrate flow and 4.62 cm membrane height. The optimum predicted yields was 67.86% and the verified value was 66.3±3.8. In addition, the effect of mass transfer in the system has also been studied. Models for FAME yield have been developed for cases of reaction control and mass transfer control. The results showed very good agreement compatibility between mass transfer model and the experimental results obtained from immobilized lipase system, showing that the FAME transesterification was mass transfer controlled.