氯代异戊烯的合成及其异构化反应

Synthesis and Isomerization of Chlorinated Isopentene

采用气液固三相鼓泡反应器,以异戊二烯和氯化氢为原料,合成1-氯代异戊烯。分别考察了氯化氢气体流量对反应速率及产物收率的影响、异戊二烯反应深度以及停通氯化氢气体后不同间隔时间吹扫对副产二氯代异戊烷的影响以及温度对3-氯代异戊烯异构为1-氯代异戊烯的影响。结果表明,异戊二烯和氯化氢高效合成氯代异戊烯适宜的反应条件为异戊二烯85 g,氯化亚铜1 g与乙酸1 g复合催化剂,HCl气体流量为320 m L/min,15-20℃下反应1.5 h,在异戊二烯质量分数为3%-5%时,停通氯化氢,立即改通120 m L/min的N2吹扫1 h,可得到异戊二烯的转化率为96%-98%,1-氯代异戊烯的收率为83%-85%。在0℃时,3-氯代异戊烯异构为1-氯代异戊烯的平衡常数可达到9.21,该异构化反应的反应热为-9.64 k J/mol,为放热反应,低温对3-氯代异戊烯异构为1-氯代异戊烯有利。

1-chloroisopentene was synthesized with isoprene and hydrogen chloride as raw materials in a three-phase bubbling reactor. The influence of the flow of hydrogen chloride, the reactive depth of isoprene and purging with N2at different time intervals after stopping loading hydrogen chloride on the conversion of isoprene and the yield of 1-chloroisopenteneand dichlorohydrins isopentane was investigated. The results showed that the appropriate reaction conditions were 85 g isoprene, 1 g cuprous chloride and 1 g acetate acid, at 320 mL/min hydrogen chloride for 1.5 h,when residual quantity of isoprene being 3%-5%（mass fraction） stopping hydrogen chloride and purging with N2at 120 mL/min for 1 h at 15-20℃,the conversion of isoprene and the yield of 1-chloroisopentene reached 96%-98% and 83%-85%, respectively. The equilibrium time and composition which the isomerization reached equilibrium were obtained.The equilibrium constant of 3-chloroisopentene to 1-chloroisopentene reached 9.21 at 0℃. The reaction heat of the isomerization was -9.64 kJ/mol, and low temperature was favorable for 3-chloroisopentene to 1-chloroisopentene.