不同硅铝比HZSM-5分子筛催化MTG反应性能研究  

Effect of SiO_2/Al_2O_3 ratio on methanol to gasoline reaction catalyzed by HZSM-5 zeolites

作　　者：孙振海[1] 宋宝东[1] 曹刚 刘斌[1] 

机构地区：[1]天津大学化工学院化学工程研究所,天津300072 [2]天津南化催化剂有限公司,天津300071

出　　处：《化学工程》2015年第6期55-59,共5页Chemical Engineering(China)

基　　金：国家高技术研究发展计划(863计划)(2012AA051003);天津市科技型中小企业技术创新基金

摘　　要：和传统石化法相比,MTG法制得的汽油具有辛烷值高,不含硫、氯等有害或腐蚀性杂质的优点,MTG工艺核心是HZSM-5分子筛。在固定床反应器中,400℃,1 MPa,甲醇质量空速5 h-1下,研究了25,38,50,80这4种不同硅铝比(摩尔比)的HZSM-5分子筛催化MTG反应性能,采用N2吸附脱附、NH3-TPD对分子筛进行表征。结果表明:硅铝比增加,分子筛酸性减弱,催化MTG反应活性降低;随反应进行,4种HZSM-5分子筛总芳烃选择性降低(其中均四甲苯选择性增加);从催化活性和抗积碳失活能力方面综合分析,酸性适中、中孔孔容最大,硅铝比为50的HZSM-5分子筛催化性能最优,反应24 h,甲醇转化率和汽油选择性分别降低12.7%和16.7%。Compared with the traditional technology for producing gasoline from fossil fuel,the methanol to gasoline（ MTG） technology has the advantages of producing high octane number gasoline with no sulfur,chlorine and other harmful or corrosive impurities. The HZSM-5 zeolite plays a crucial role in the MTG process as the catalyst. In a fixed bed reactor,the MTG reaction catalyzed by HZSM-5 zeolite at different Si O2/ Al2O3 mole ratios（ 25 ∶ 1,38 ∶ 1,50 ∶ 1 and 80 ∶ 1） was investigated at 400 ℃ and WHSV of 5 h- 1under 1 MPa. The catalyst samples were characterized by nitrogen adsorption-desorption and NH3-TPD techniques. It shows that with the increase in Si O2/Al2O3 ratio,the acidity of molecular sieves is reduced and the catalytic activity of the catalyst is decreased. Along with the reaction,total aromatics selectivity is decreased and the sym-tetramethylbenzene（ STMB） selectivity is increased. Comprehensively considering the catalytic activity and anti-carbon deactivation ability,the HZSM-5zeolite at a Si O2/ Al2O3 ratio of 50 ∶ 1 is the best,which has a moderate acidity and largest internal pore volume.After reaction for 24 h,the methanol conversion and gasoline selectivity are reduced by 12. 7% and 16. 7%,respectively.

关 键 词：MTG HZSM-5 催化剂活性 汽油选择性 芳烃 

分 类 号：TE665[石油与天然气工程—油气加工工程]