HZSM-5催化合成苄基甲苯的研究

Synthesis of benzyl-toluene using HZSM-5 as catalyst

利用HZSM-5为催化剂催化合成苄基甲苯,研究了反应温度、投料比、反应时间、催化剂用量、搅拌转速对反应的影响,通过气相色谱分析了转化率,通过核磁和红外光谱对反应产物进行了表征。实验结果表明,HZSM-5适合作为该反应的催化剂。当反应温度125℃,催化剂质量浓度0.06 g/mL,搅拌转速800 r/min,反应时间4 h,原料比n甲苯∶n氯化苄=3∶1时,主要产物为单苄基甲苯(MBT),而n甲苯∶n氯化苄=3∶2时,主要产物为双苄基甲苯(DBT)。实验证明,不但能通过调节投料比来调节单苄基甲苯和双苄基甲苯产物的比例,而且洗涤过程中消耗碱量极少,对环境几乎无污染,转化率达90%。另外,HZSM-5为非均相催化,该催化剂不但可回收处理,而且继续使用3次其催化效果均变化不大。

The benzyl-toluene is synthesized use HZSM- 5 as catalyst, and the effects of reaction temperature, feeding-ratio, reaction time, the amount of catalyst and agitating speed are researched. The products are analysized and charactered by GC, NMR and IR. The results show that HZSM- 5 is suited to this reaction. Under the conditions of boiling temperature, the amount of catalyst to 0.06 g/mL, agitating rate for 800 r/min, reaction time for 4 h, n（toluene ： n（benzyl choloride）=3 ： 1, the main product could be as mono-benezyl-toluene （MBT）, and when n（toluene ： n（benzyl chnoloride） = 3 ： 2, the main product could be as dihenzyl-toluene （DBT）. This method can not only regulate the main product by reguluting the feed, but also consume minimal alkali in the washing process. It is virtual no pollution to the enviorment. The benzyl choloride coversation rate could be high to 90%. In addition, the HZSM - 5 is non-homogeneous catalyst. The recycling experiment of the catalyst proved that catalytic effect changes little after reuseing three times.