影响乙苯异构化催化剂性能的因素研究

FACTORS AFFECTING PERFORMANCE OF ETHYLBENZENE ISOMERIZATION CATALYST

针对乙苯转化为二甲苯反应过程开展研究,考察了催化剂的金属分散度、载体物化性质、B酸强度等因素对乙苯异构化反应的影响。结果表明:金属铂分散度为7.1%时,乙苯转化能力达到最佳;载体颗粒大小对金属分散影响较大,随着载体颗粒变小,金属分散度提高,乙苯转化率上升;不同结构分子筛的乙苯转化能力不同,氨脱附温度为350~450℃时的B酸量增多,乙苯转化率提高。基于上述研究,中国石化石油化工科学研究院研制开发了RIC-270新型C_8芳烃异构化催化剂,工业应用结果表明,与原RIC-200催化剂相比,RIC-270催化剂的乙苯转化能力明显提高,乙苯转化平衡达成率达到81.7%,并维持较低的C_8非芳烃含量,可有效提高反应产物中的对二甲苯含量。

The conversion of ethylbenzene to xylene was studied.The effects of metal dispersion,physical and chemical properties of the carrier,and the strength of B acid on the isomerization of ethylbenzene were investigated.The results showed that the conversion ability of ethylbenzene reaches the best level when the dispersion of platinum is 7.1%.The size of carrier particles has a great influence on the dispersion of metal,and the conversion of ethylbenzene increases with the decreases of carrier particles and increases of metal dispersion.The ethylbenzene conversion capacity is different with structures of molecular sieves.When the ammonia desorption temperature is 350—450℃,the ethylbenzene conversion rate increases due to increase of B acid amount.Based on the above studies,a new type of catalyst RIC-270for isomerization of C8aromatics was developed by SINOPEC Research Institute of Petroleum Processing.The industrial results showed that compared with RIC-200catalyst,the ethylbenzene conversion capacity of RIC-270is obviously improved,and ethylbenzene conversion reaches 81.7%at equilibrium.The lower content of C8non-aromatics effectively improves para-xylene content in the reaction product.