合成了5种新型咪唑类和吡啶类双核酸性离子液体,并考察了其催化餐饮废油酯交换制备生物柴油的性能。实验表明,咪唑类双核酸性离子液体具有很好的催化活性,其中[MIM]2C3[HSO4]2催化活性最好。在以[MIM]2C3[HSO4]2为催化剂条件下,通过单因素实验和正交实验考察了醇油摩尔比、反应温度、反应时间和催化剂用量对酯交换反应的影响,并考察了双核酸性离子液体的稳定性。结果表明:在醇油摩尔比45∶1、反应温度170℃、反应时间2 h和催化剂用量为餐饮废油质量8%的条件下,生物柴油产率可达95.8%,并且该双核酸性离子液体的稳定性良好,循环使用6次后其催化活性没有明显降低。
Five novel acidic dication ionic liquids, imidazolium and pyrimidinium, were synthesized and their catalytic performances in the transesterification of waste cooking oil to prepare biodiesel were studied. The results showed that imidazolium acidic dication ionic liquids exhibited good catalytic activity, in which the catalytic activity of [MIM] 2C3[HSO4] 2 was the best. With [MIM]2C3 [HSO4] 2 as catalyst, the influences of molar ratio of methanol to oil, reaction time, reaction temperature and catalyst dosage on the transesterification were investigated by single factor experiment and orthogonal experiment, and the stability of the acidic dieation ionic liquid was also researched. The results showed that the optimal reaction conditions were obtained as follows: ratio of methanol to oil 45: 1, reaction temperature 170℃, reaction time 2 h, catalyst dosage 8% (based on the mass of waste cooking oil ), under these conditions, the yield of biodiesel was up to 95.8%. Moreover, the acidic dication ionic liquid had good stability and no obvious decrease in catalytic activity after being reused for six times.