柴油溶剂中脂肪酶催化高酸值废油脂酯化制备生物柴油

采用0＃柴油作为反应溶剂，利用固定化脂肪酶催化高酸值废油脂与甲醇酯化反应制备生物柴油。来源于Candida antarctica的固定化脂肪酶Novozym435在0＃柴油溶剂中具有极高的催化活性。以酸价高达157×10-3的废油脂为原料，废油脂质量比10%的Novozym435，甲醇与废油脂初始摩尔比2∶1，0＃柴油与废油脂质量比5∶1，摇床摇速170r/min，50℃下反应2h甲酯化率可达95.10%。0＃柴油作为反应溶剂有效地溶解了高酸值废油脂和甲醇，降低了反应体系的黏度和消除了甲醇对Novozym435的负面影响，提高了Novozym435的稳定性。同时，0＃柴油溶剂对未脱胶废油脂中残留的对脂肪酶有害的磷脂等胶类物质具有一定的稀释作用。该工艺省却了溶剂蒸馏的繁琐工序，直接得到脂肪酸甲酯和石化柴油的混合燃料。

Lipase-catalyzed esterification of high acid value waste oil to produce biodiesel with diesel oil as solvent

Diesel oil (0#) was used as the reaction solvent for lipase catalyzed esterification of high acid value waste oil to produce biodiesel; in this way, the resultant mixture could be directly used as diesel oil and the troublesome operation of distillation and reclamation of solvent was avoided. The optimum conditions for esterification of high acid value waste oil were as follow: the amount of Novozyme435 being 10% based on oil weight, initial molar ratio of methanol to oil being 2∶1, weight ratio of diesel oil to waste oil being 5∶1, shaking rate of 170r/min; the esterification conversion of fatty acid to methyl ester reached 95.10% after reaction at 50℃ for 2h and the stability of Novozyme435 was also improved obviously with diesel oil as solvent. Moreover, the diesel oil may dilute the rudimental phospholipids harmful to lipase in the waste oil slightly, though the degumming treatment of waste oil is still a key factor to determine the stability of Novozyme 435 and the feasibility of producing biodiesel from high acid value waste oil.