碱金属离子改性对纳米HZSM-5沸石丁烯裂解催化性能的影响  

Effect of alkali metal ion modification on the catalytic performance of nano-HZSM-5 zeolite in butene cracking

作　　者：徐瑞芳[1] 刘家旭[1] 梁翠翠[1] 贾文浩[1] 李福芬[1] 郭洪臣[1] 

机构地区：[1]大连理工大学化工学院催化化学与工程系精细化工国家重点实验室,辽宁大连116012

出　　处：《燃料化学学报》2011年第6期449-454,共6页Journal of Fuel Chemistry and Technology

摘　　要：利用NH3-TPD表征和小型固定床反应评价研究了不同碱金属离子浸渍改性对纳米HZSM-5沸石的酸度及混合碳四液化气中丁烯催化裂解性能的影响。结果表明,尽管锂、钠、钾改性在达到最佳乙烯和丙烯选择性时对应的负载量不同,但其最佳乙烯和丙烯选择性为50%～60%。碱金属离子改性催化剂在连续运转过程中其催化活性缓慢下降,但乙烯和丙烯选择性没有明显增加。丁烯异构体在催化剂上转化率由大到小的顺序为:丁烯1->反丁烯-2>顺丁烯2->异丁烯。Nano-HZSM-5 was modified by different alkali metal ions;the effect of the modification on its acidity and catalytic performance in butene cracking was investigated by using NH3-TPD characterization and catalytic evaluation in a small fixed-bed reactor.The results indicated that although the catalysts modified with various ions of Li,Na and K are different in their metal loading required to achieve the highest selectivity to ethylene and propylene,the best selectivity value obtained over all these modified catalysts is located in 50%~60%.The activity of the alkali modified catalysts decreases slowly with the extension of the reaction time on stream;however,the selectivity to ethylene and propylene does not increase accordingly.The conversions of different butene isomers over the zeolite catalysts are decreased in the sequence of butene-1 trans-butene-2 cis-butene-2 iso-butene,which may reflect the order of their reactivity towards cracking.

关 键 词：碱金属离子 纳米HZSM-5沸石 丁烯 催化裂解 丙烯 碳四液化气 

分 类 号：O643[理学—物理化学]