中文摘要：

试验研究了以地沟油为原料，在脂肪酶作用下与甲醇发生酯交换反应制备生物柴油的工艺条件，通过单因素试验和正交试验对该工艺的操作条件进行优化．得到最佳的工艺条件为醇油摩尔比为2：1,脂肪酶催化剂用量按每克油脂90U添加，正己烷和水添加量均为油重的10％，反应温度为20℃，反应时间为28h，甲酯得率为97．12％。该新工艺与传统工艺相比，具有操作简单，转化率高，成本低，可重复性好等优点，有利于为酶法制备生物柴油的产业化发展提供一定理论基础。

英文摘要：

The transesterification of waste oils by lipase has been studied in the experiments .The optimum reaction conditions is obtained through single factor and orthogonal experiment, and the results showed that the alcohol-oil molar ratio is about 2：1, the lipase amount of catalyst is 90 U/g （oil）, the water content and n-hexane are all 10%,the reaction temperature is 20 %,and the reac-tion time is 28 h, the methyl yield is 97.12%. This new process has many advantages compared with the old processes, such as simple operation, high efficiency, low equipment cost, repeatability, which would beneficial for the industrial development of the biodiesel by enzymatic preparation.