[BMIM]HSO_4/Al_2O_3的制备及其在甘油脱水反应中的应用研究

采用两步法合成离子液体BMIM]HSO4,并采用浸渍法制备了BMIM]HSO4/Al2O3催化剂,用IR、NMR、TG-DTG等方法对催化剂进行表征,并在常压连续流动的固定床反应器中考察其催化甘油脱水制备丙烯醛的性能,重点考察了催化剂离子液体的负载量、反应温度、体积空速对反应的影响及催化剂的稳定性。结果表明,较优条件为:BMIM]HSO4/Al2O3催化剂w(BMIM]HSO4)为40%、反应温度为300℃、体积空速为6h-1,此时丙烯醛的摩尔选择性可达90.22%,甘油的转化率为100%,且催化剂在反应100h后仍保持75%的收率。

Preparation of [BMIM]HSO4/Al2O3 and its use for dehydration of glycerol to acrolein

The ionic liquid BMIM]HSO4 was synthesized by two steps and the Al2O3-supported BMIM]HSO4 catalyst BMIM]HSO4/Al2O3 was prepared by impregnation method.The catalyst was characterized by IR,TG-DTG and NMR,and its performances of catalytic dehydration of glycerol to acrolein were investigated in a fixed-bed flow reactor with the emphasis on the effects of reaction conditions including ionic liquid loading amount of catalyst,temperature and space velocity on the reaction and the stability of catalyst.The results showed that the optimum reaction conditions were as follows: ionic liquid mass fraction in catalyst of 40%,temperature of 300℃ and liquid hourly space velocity of 6 h-1.Under the optimum conditions,the acrolein molar selectivity and glycerol conversion were 90.22% and 100%,respectively,and after 100 hours on stream,the yield of acrolein still reached 75%.