HZSM-5分子筛上苯、甲醇脱附规律及烷基化反应  

The Desorption Law and Alkylation of Benzene With Methanol on HZSM-5 Zeolites

作　　者：孙仁山[1] 黄星亮[1] 赵蕾蕾[1] 龚艳[1] 张鑫[1] 字琴 曹中扬 

机构地区：[1]中国石油大学化学工程学院,北京102249

出　　处：《石油学报（石油加工）》2017年第5期927-933,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(21576288)资助

摘　　要：对不同n(SiO_2)/n(Al_2O_3)的HZSM-5分子筛进行了程序升温表面反应-质谱(TPSR-MS)表征,并采用程序升温脱附(TPD)法考察了苯、或甲醇2种物质在HZSM-5上的吸附脱附性能。结果表明,随HZSM-5分子筛n(SiO_2)/n(Al_2O_3)增加,酸强度降低,酸量减少;苯于60℃下吸附后程序升温脱附的过程中检测到乙烯,随n(SiO_2)/n(Al_2O_3)增高,检测到的乙烯越少,苯脱附量越高;甲醇于60℃下吸附后程序升温脱附的过程中检测到甲苯,但未检测到苯,n(SiO_2)/n(Al_2O_3)越高,检测到的甲苯量越小,甲醇脱附量越多。这表明HZSM-5分子筛n(SiO_2)/n(Al_2O_3)越高,越有利于苯、甲醇的单分子吸附。烷基化评价结果表明,高n(SiO_2)/n(Al_2O_3)的HZSM-5分子筛烷基化活性较好,低n(SiO_2)/n(Al_2O_3)的HZSM-5分子筛易失活,HZSM-5分子筛酸性质是影响苯-甲醇烷基化反应的主要因素之一。Temperature-programmed surface reaction mass spectrometry（TPSR-MS）experiments were conducted on HZSM-5 zeolites of different n（SiO_2）/n（Al_2O_3）,and temperature-programmed desorption（TPD）method was used to investigate the adsorption-desorption performances of benzene or methanol on the zeolites.The results showed that with increased n（SiO_2）/n（Al_2O_3）of HZSM-5 zeolites,the acid strength and acid quantity declined.Ethylene was detected during TPD after benzene adsorpted on HZSM-5 at 60℃,and the higher silica to alumina ratio,the less ethylene was detected and the more desorption of benzene occurred.Toluene was found during TPD after methanol adsorbed on HZSM-5 at 60℃,but benzene was not detected;with the higher silica to alumina ratio,the less amount of toluene was detected and the more desorption of methanol occurred.The above results showed that the high n（SiO_2）/n（Al_2O_3）of HZSM-5 is beneficial for benzene or methanol to exist in the form of a single molecule.The alkylation results showed the HZSM-5 of high n（SiO_2）/n（Al_2O_3）were favorable to reaction of benzene and methanol,but HZSM-5 of lown（SiO_2）/n（Al_2O_3）were easily deactivated;clearly,the acidity plays an important role in alkylation of benzene and methanol.

关 键 词：n(SiO2)/n(Al2O3) HZSM-5 程序升温表面反应 苯-甲醇烷基化 

分 类 号：TE65[石油与天然气工程—油气加工工程]