基于酸催化的餐饮业废弃油脂与醇类酯化反应试验研究

Experiment of transesterification between waste oils and methanol or ethanol based on acid catalyzing

为确定酸催化餐饮业废弃油脂(地沟油)与醇类酯化反应的最佳反应条件,以浓H2SO4为催化剂对其酯化反应进行了正交试验。结果表明:与甲醇的最佳反应条件为温度70℃,油醇摩尔比1∶40,浓H2SO4质量分数7%,反应时间6 h;级差分析表明影响产率的因素依次为,油醇摩尔比>反应时间>浓H2SO4质量分数>反应温度。与乙醇的最佳反应条件为温度80℃,油醇摩尔比1∶30,浓H2SO4质量分数5%,反应时间6 h;影响产率的因素依次为,油醇摩尔比>反应温度>浓H2SO4质量分数>反应时间。浓H2SO4作催化剂时甲醇和乙醇均可作为反应醇。考虑到甲醇具有很强的极性和活性,且价格较乙醇便宜,在实际生产中可选用甲醇作为反应物。

In order to determine the best reaction condition for transesterification reactions of acid catalyzing waste oil and alcoholic compounds, the orthogonal tests of waste oil with methanol and waste oil with ethanol catalysed by concentrated H2SO4 were carried out. The best condition for methanol is temperature of 70℃, the proportion of methanol and waste oil of 1 ：40, the dosage of catalyst of 7% and the reaction time of 6 hours and the influencing parameters are the proportion of methanol and waste oil, the dosage of catalyst, the time of reaction, and temperature in sequence. For ethanol, they are temperature of 80℃, the proportion of methanol and waste oil of 1：30, the dosage of catalyst of 5%, the reaction time of 6 hours, and their influencing parameters are the proportion of methanol and waste oil, temperature, the dosage of catalyst and the time of reaction in sequence. When concentrated H2SO4 is used as catalyst, both methanol and ethanol can be applied as reaction alcoholic compounds. Methanol will be chose as the reactant in the production for its strong polarity, activity and low price.