酸性低共熔溶剂催化葵花籽油甲酯化反应研究

Methyl esterification of sunflower oil catalyzed by acidic deep eutectic solvent

低共熔溶剂作为一类新型溶剂,可作为催化剂降低生物柴油的生产成本,简化生物柴油纯化过程,减少环境污染。以氯化胆碱(ChCl)与对甲苯磺酸(PTSA)组成的酸性低共熔溶剂(DES)为催化剂,催化葵花籽油与甲醇酯交换反应制备葵花籽油脂肪酸甲酯。通过单因素试验得到最优反应条件:反应温度120℃,反应时间50 min,DES-5的添加比例5%,醇油物质的量比8∶1,转速600 r/min,此时酯化率达到98.23%±0.06%。研究了DES-5与PTSA催化葵花籽油甲酯化产物的特性,发现DES-5催化所得的葵花籽油甲酯羟值、水分含量和甘油一酯都较低。DES能够应用于生物柴油的制备,并得到高纯度的生物柴油产品。

As a new kind of solvent,deep eutectic solvent can be used as catalyst to reduce the production cost of biodiesel,simplify the purification process and reduce environmental pollution.In this study,an acidic deep eutectic solvent(DES)composed of ChCl and PTSA has been studied as the catalyst in transesterification of sunflower oil and methanol to produce biodiesel.The optimal conditions were obtained by single factor experiment:reaction temperature was 120℃,reaction time was 50 min,the amount of DES-5 was 5%,the molar ratio of alcohol to oil was 8∶1,and the rotation speed was 600 r/min.In this condition,the esterification conversion reached 98.23%±0.06%.The characteristics of methyl esters of sunflower oil catalyzed by DES-5 and p-toluenesulfonic acid(PTSA)were also studied.It was found that the hydroxyl value,water content and glyceryl ester were lower when the methyl esters were obtained using DES-5 as catalyst.The results show that DES can be used in the preparation of biodiesel and high purity biodiesel products can be obtained.