响应面法优化酶催化酯交换反应研究

为了利用植物油生产可再生的绿色能源——生物柴油,文章利用Novo435固定化脂肪酶,在无有机溶剂存在下催化菜籽油与甲醇酯交换合成生物柴油。利用响应面实验设计和分析方法对菜籽油的酯交换反应条件进行优化,得到了最佳工艺条件:醇油摩尔比1.5∶1,反应温度52℃,搅拌转速200 r/min,脂肪酶与油脂的质量比为10%,反应时间10 h,在此工艺条件下油脂的酯交换率达到48%(理论为50%)。理论甲醇量分3批加入,反应36 h后菜籽油的总酯交换率达到95%(理论酯交换率为100%)。每批试验后利用有机溶剂对脂肪酶进行清洗,然后继续反应,连续使用10个批次,油脂的酯交换率基本未变。

Optimization of lipase-catalyzed transesterification by response surface methodology

Biodiesel,an alternative diesel fuel,is made from renewable biological resources,and with the depletion of the fossil fuel it has become more and more attractive recently.The immobilized lipase-Novo435 was used to catalyze transesterification reaction of rapeseed oil with methanol without organic solvent.The response surface methodology was used to optimize the transesterification reaction conditions of rapeseed oil,and the optimized conditions of the reaction was found: the molar ratio of methanol and oil is 1.5 ∶1,reaction temperature is 52 ℃,rotation rate is 200 r/min,lipase mass ratio is 10%,and reaction time is 10 h.Under these optimal conditions,48% of the oil was converted to its corresponding methyl esters(the theoretical conversion rate is 50%).The theoretical methanol amount needed by the reaction was fed in three steps,and 95% of the oil was converted to its corresponding esters(the theoretical conversion rate is 100%).The lipase was washed by organic solvent after each cycle test,and then was continuously reused for 10 cycles nearly without any loss of the activity.