固定化脂肪酶催化棉籽油与碳酸二甲酯反应制备生物柴油

以叔丁醇为有机溶剂,采用固定化脂肪酶Novozym435催化棉籽油与碳酸二甲酯进行酯交换反应制备了生物柴油,考察了加水量、碳酸二甲酯与棉籽油的摩尔比、反应温度、反应时间、搅拌转速、Novozym435用量(基于棉籽油的质量分数)和叔丁醇与碳酸二甲酯的体积比对脂肪酸甲酯收率的影响,以及Novozym435的重复使用性能。实验结果表明,在碳酸二甲酯与棉籽油的摩尔比为4、叔丁醇与碳酸二甲酯体积比为1.5、Novozym435用量(基于棉籽油的质量分数)12.5%、反应温度50℃、反应时间24h、搅拌转速160r/min、不加水的优化反应条件下,脂肪酸甲酯收率可达96%以上;与石油醚溶剂相比,Novozym435在叔丁醇溶剂中的稳定性较好。

Synthesis of Biodiesel from Cottonseed Oil and Dimethyl Carbonate Catalyzed by Immobilized Lipase

Synthesis of biodiesel via transesterification of cottonseed oil with dimethyl carbonate catalyzed by immobilized candida antarctica lipase(Novozym435) in t-butanol solvent was studied.Effects of water addition amount,n(dimethyl carbonate)∶n(cottonseed oil),reaction temperature,reaction time,Novozym435 dosage,stir speed and V(t-butanol)∶V(dimethyl carbonate) on yield of fatty acid methyl ester were investigated.Under optimal transesterification conditions: n(dimethyl carbonate)∶n(cottonseed oil) 4,V(t-butanol)∶V(dimethyl carbonate) 1.5,mass fraction of Novozym435 12.5%(based on cottonseed oil),reaction temperature 50 ℃,reaction time 24 h,stir speed 160 r/min and without addition of water,yield to fatty acid methyl ester was above 96%.Reusability of Novozym435 was improved greatly in comparing with using petroleum ether as solvent of the reaction system.