利用地沟油制备生物柴油

Preparation of biodiesel with hogwash oil

以废弃地沟油为原料,经预处理后采用两步酯化工艺将其转化为生物柴油。第一步为酸催化预酯化反应,主要是将地沟油中的游离脂肪酸转化为脂肪酸甲酯;第二步为酸催化转酯化反应,主要是进一步将地沟油中的甘三酯转化为甲酯和甘油。通过正交实验得到预酯化反应的最佳条件为:醇油摩尔比10∶1、催化剂用量1.0%、反应温度70℃、反应时间4 h;转酯化反应的最佳条件为:醇油摩尔比20∶1、催化剂用量6%、反应温度70℃、反应时间4 h。在最佳反应条件下,甘三酯的酯化率可达到86.89%。

A two - step process was developed to convert the hogwash oil pretreated to biodiesel. The first step was esterifying FFA to its methyl esters. The second step was transesterifying the products of the first step to methyl esters and glycerol. Through orthogonal experiment triglycerides in the ,the optimum con- ditions were obtained for esterification as follows： reaction temperature 70℃, molar ratio of methanol to oil 10：1, dosage of catalyst 1.0% and reaction time 4 h;the optimum conditions of transesterification obtained were as follows： reaction temperature 70℃, molar ratio of methanol to oil 20：1, dosage of catalyst 6% and reaction time 4 h. Under the optimum conditions, the transesterification rate reached 86. 89%.