超临界酯交换法制备生物柴油的研究

Development in Production of Biodiesel Fuel Using Supercritical Esterification Method

综述了超临界酯交换法制备生物柴油的反应机理及动力学、影响因素、生产工艺及与其他酯交换法的比较，其中影响因索包括反应温度、醇油比、反应压力、反应时间、游离脂肪酸、水、原料油、醇和共溶剂。并重点对这些影响因素进行分析比较，结果表明，反应温度选择350℃；醇油比通常取42：1；当温度在280—295℃时，反应压力对转化率影响不大，温度350℃时，反应压力对转化率影响较大；反应时间30min，原料油中含游离脂肪酸和水对转化率影响均不大；原料油中不饱和度高的组分反应速度快于饱和度高的组分；在超临界区烃链越短的醇反应速度越快；加入共溶剂可降低反应苛刻度。与其他酯交换法相比，超临界酯交换法具有反应速度快、不需催化剂、成本低和环境友好等特点。

Reaction mechanism and kinetics, factors on reaction, and processes for production of biodiesel percritical esterification method were reviewed and the comparison with other esterification methods were using sumade. The factors included reaction temperature, ratio of alcohol to oil, reaction pressure, reaction time, free fatty acid, water, feed oil, alcohol and cosolvent. The emphasis was on the comparison of the above mentioned factors. The result showed that suitable reaction temperature was 350℃, and the suitable mass ratio of alcohol to oil was 42 ： 1. The effects of reaction pressure on reaction was not obvious was rather obvious when reaction temperature was 350 when reaction temperature was 280- 295℃, but the effects℃. The effects of free fatty acid and water in oil on the conversion were insignificant when reaction was carried out in 30 minutes. The components with high unsaturation degree in oils was reacted more rapidly than with high saturation degree. The shorter the chain in alcohol, the faster reaction rate in supercritical zone. Cosolvent could decrease the reaction severity. Compared with other esterification methods, supercritical esterification method had characteristics in fast reaction,no catalyst, low cost,friendly environment.