高温低压法降低地沟油酸值的工艺条件研究

Reduction of acid value of swill - cooked dirty oil high temperature and low pressure method

在高温、低压和无催化剂条件下，通过连续移除地沟油与甲醇酯化反应所生成的水，打破反应平衡，达到降低地沟油酸值的目的。通过跟踪酯化反应进度和速度，考察了不同反应温度、反应压力下，酯化降酸反应效果与反应时间的关系。结果表明：在反应温度230℃、反应压力0．6MPa、反应时间45min、醇油摩尔比约为23：1条件下，地沟油的酸值（KOH）可降至2mg／g以下。采用所述方法降酸后的地沟油可进一步进行酯交换反应，制备生物柴油。

The acid value of swill - cooked dirty oil was reduced by continuously removing water generated in the esterification of swill - cooked dirty oil and methanol under the conditions of high temperature and low pressure without catalyst. Through tracking the progress and speed of the esterification reaction, the relationship between acid value reduction effect and reaction time under different reaction temperatures and pressures was studied. The results showed that the acid value of swill - cooked dirty oil was reduced to less than 2 mgKOH/g under the conditions of 230 ℃ of reaction temperature ,0.6 MPa of reaction pres- sure ,45 rain of reaction time and 23：1 of molar ratio of methanol to swill -cooked dirty oil. The swill - cooked dirty oil obtained could be transesterified to prepare biodiesel.