固定化离子液体高效催化废弃食用油合成生物柴油

采用溶胶?凝胶技术和浸渍法制备了固定化1-(4-丁基磺酸)-3-甲基咪唑硫酸氢盐([(n-Bu-SO3H)MIm][HSO4])离子液体(IL)，得到了一种适用于游离脂肪酸和甲醇酯化反应的不溶性IL催化体系，对合成的催化剂进行了表征，并对其活性进行了系统评价. 结果表明，离子液体成功负载于载体上，该固定化Br?nsted性离子液体在油酸和甲醇酯化反应中具有非常好的催化活性，在最佳反应条件下，油酸的转化率高达98.4%. 该催化剂用于催化高游离脂肪酸含量的废弃食用油酯化时，经后续碱催化酯交换反应，可获得收率高达94.7%的生物柴油.

Efficient conversion of waste cooking oil into biodiesel catalyzed by immobilized ionic liquid

Ionic liquids possess excellent catalytic activities for various chemical reactions including esterification reaction, but the difficulty in phase separation is a major barrier. An immobilized ionic liquid (IL), 1-(4-butylsulfonic)-3-methylimidazolium hydrosulfate [(n-Bu-SO3H)MIm][HSO4], based on sol?gel technique and wetness impregnation method was developed in order to obtain an insoluble IL catalytic system suitable for the esterification of free fatty acids and methanol. The synthesized catalysts were characterized by various techniques and the catalytic properties were fully evaluated. The results demonstrated that the ionic liquid was successfully incorporated into the support. This immobilized Br?nsted ionic liquid catalysts displayed relatively high catalytic activity in esterification of oleic acid and methanol. Under the optimum reaction conditions, the conversion of oleic acid reached to 98.4%. The catalyst was also applied to catalyze the esterification of real waste cooking oil having high free fatty acid and followed by alkyli-catalyzed transesterification, a biodiesel yield of 94.7% was achieved.