Brønsted-Lewis双酸性离子液体催化大豆油制备生物柴油

摘要

A series of Brønsted–Lewis acidic ionic liquid [Py(CH2)4SO3H][HSO4]/MClX were synthesized,and they were used as catalyst in the transesterification of soybean oil with methanol to produce biodiesel. Effects of the species of metal chlorides and molar ratio of metal chlorides to [Py(CH2)4SO3H][HSO4] on the catalytic properties were studies,[Py(CH2)4SO3H][HSO4]–2FeCl3 showed excellent activity in the transesterification. Factors influencing on yield of biodiesel catalyzed with ionic liquid [Py(CH2)4SO3H][HSO4]–2FeCl3 were investigated following molar ratio of methanol to soybean oil,catalyst concentration,reaction temperature and reaction time. Results showed that the yield of biodiesel could reach to 96.2%under the conditions with the molar ratio of methanol to soybean oil 8∶1,catalyst dosage 5%,reaction temperature 130℃,reaction time 6 h. The ionic liquid could be recycled 6 times with only a slight decrease in activity.%设计合成了一系列Brønsted–Lewis双酸性离子液体[Py（CH2）4SO3H][HSO4]/MClX，将其用于催化酯交换制备生物柴油。考察了金属氯化物的种类及其与[Py（CH2）4SO3H][HSO4]的摩尔比对离子液体催化性能的影响。结果显示：离子液体[Py（CH2）4SO3H][HSO4]–2FeCl3具有最好的催化性能。在其作为催化剂时，考察了醇油摩尔比、催化剂用量、反应温度和反应时间对生物柴油收率的影响。结果表明：当醇油摩尔比为8∶1，催化剂用量为5%（相对于原料油质量），反应温度为130℃，反应时间为6 h时，生物柴油收率可达96.2%。离子液体具有较好的重复使用能力，重复使用6次后，生物柴油收率没有明显降低。