超稳Y沸石催化剂的积炭行为和酸性调变  

COKING BEHAVIOUR AND ACIDITY ACCOMMODATIONS OF USY ZEOLITE CATALYSTS WITH VARIOUS Si/Al RATIOS

作　　者：潘惠芳[1] 苏建明[1] 王彪[1] 罗守坤[2] 王进善[2] 

机构地区：[1]石油大学 [2]齐鲁石化公司研究院

出　　处：《石油学报（石油加工）》1992年第3期30-36,共7页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：采用热重法以正庚烷裂化反应观测了超稳Y沸石催化剂的积炭行为;采用氨吸附程序升温脱附法测量了催化剂的酸性;考察了硅铝比对催化剂酸性对积炭的影响。研究结果表明,沸石催化剂上的积炭主要发生在强酸部位;积炭速率与强酸量之间存在着r_c^+=KA~α的定量关系;强酸部位因积炭和脱铝导致酸量下降,使催化剂的活性衰减;改变硅铝比对酸性产生有效的调变作用,从而抑制了催化剂的积炭失活。The coking behaviour of USY zeolite catalysts with various SiO_2/Al_2O_3 ratios during the cracking of n-heptane has been investigated by means of thermogravimetry. The acidity of USY zeolite catalysts was examined by ammonia adsorption and TG-DTG. The rate of coking during cracking reaction is an inverse measure of Si/Al ratio. It has been found that coke deposit occurs mainly on strong acid sites. The correlation equation of coking rate to strong acid site number was derived. The decrease of the strong acid site number due to coke deposit and removal of framework aluminium causes the deactivation of the catalyst during cracking. Changing the Si/Al ratio of USY catalyst is effective for surface acidity accommodation, thus the catalyst deactivation caused by coking during cracking can be controlled.

关 键 词：USY 沸石 催化剂 积炭 酸性调变 

分 类 号：O643.36[理学—物理化学]