新型C_8芳烃异构化催化剂Ⅱ.工艺条件的研究

选用具有独特结构的十二元环中孔分子筛为酸性组元,制备了新型C8芳烃异构化催化剂,研究了工艺条件对催化剂性能的影响,并考察了该催化剂的稳定性。实验结果表明,该新型C8芳烃异构化催化剂具有较高的活性和选择性,能在较高的空速下运行。优化的工艺条件为:反应压力0.75～0.85MPa,反应温度375～385℃,重时空速4.0～5.0h-1,氢油摩尔比3.8～5.0。在该工艺条件下,经过1000h的长周期运行考察,该催化剂的稳定性良好。稳定性实验的平均结果为:产物中对二甲苯(PX)平衡浓度(即PX在二甲苯中的质量分数)23.54%,乙苯转化率28.21%,C8烃收率98.38%。

A Novel C8 Aromatics Isomerization Catalyst Ⅱ.Study on Running Conditions

A novel C8 aromatics isomerization catalyst was prepared using a special zeolite.The influence of running conditions,and performance and stability of the catalyst was investigated.The catalyst is highly active and selective,and can stand a relatively high WHSV.Under optimum running conditions:reaction temperature 375-385 ℃,reaction pressure 0.75-0.85 MPa,WHSV 4.0-5.0 h-1 and mole ratio of H2 to liquid feed 3.8-5.0,equilibrium concentration of p-xylene(PX) in product(i.e.PX mass fraction in xylene) was 23.54%,ethylbenzene conversion was 28.21% and C8 hydrocarbon yield was 98.38%,during test run of 1 000 h.A favorable stability of the catalyst was proved.