甲苯择形歧化合成对二甲苯催化剂的研究与应用  

STUDY AND APPLICATION OF TOLUENE SHAPE-SELECTIVE DISPROPORTIONATION CATALYST TO PRODUCE p-XYLENE

作　　者：朱志荣[1,2] 谢在库[1] 陈庆龄[1] 孔德金[1] 李为[1] 杨为民[1] 李灿 

机构地区：[1]中国石化上海石油化工研究院,上海201208 [2]大连化学物理研究所催化基础重点实验室,辽宁大连116023

出　　处：《石油学报（石油加工）》2006年第B10期45-48,共4页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：通过研究ZSM-5分子筛的酸性、结构择形化修饰机理，研制了性能优异的甲苯择形歧化催化剂，并进行了国内首次工业应用试验。结果显示，ZSM-5在SiO2—CLD改性过程中，其结构没有发生明显变化，但其酸量随着改性程度的增加呈现逐渐下降的趋势，而酸强度分布基本保持不变。在修饰热处理过程中，由于ZSM-5少量的骨架脱铝，导致B酸量较L酸量下降幅度相对更大；聚硅氧烷SiO2-CLD改性的ZSM-5分子筛的外表面酸性位基本上已被消除，其TIPB裂解转化率相对于未改性前减少了95％，体现了较好的择形催化性能。SD01甲苯择形歧化催化剂在中国石化天津分公司芳烃装置上连续平稳运行，甲苯转化率30．7％，对二甲苯选择性93．0％，苯／二甲苯摩尔比（nB/nx）1．38，其技术指标达到或超过了报道的工业催化剂的性能指标。The shape-selective modification of the acidity and structure of ZSM-5 was investigated. And the toluene shape-selective disproportionation catalyst to produce p-xylene was developed and commercialized firstly in China. The results showed that the framework structure of ZSM-5 modified in SiOz-CLD was unchanged, and the acidic amount of the modified ZSM-5 droped gradually with the increase of modification degree, but its acidic strength distribution was almost unchanged compared to parent ZSM-5. The Br6nsted acid sites decreased more than Lewis acid sites as the framework Al in ZSM-5 lost during thermal treatment of modification. The conversion of 1,3,5- triisopropylbenzene （TIPB） in cracking over the polysiloxane-modified ZSM-5 was reduced by 95 %, so the external surface of the modified ZSM-5 may be regarded to be almost non-acidic due to elimination of external acidic sites. Therefore, the modified ZSM-5 showed a high shape-selective catalysis. SD-1 catalyst for the shape-selective disproportionation of toluene has been conducted in Aromatics Complex of Tainjing Petrochemical Company under the continuous and stable on-stream conditions. The resulted p-xylene selectivity was 93.0% , with 30.7% toluene conversion and 1.38 of nB/nx, which is superior to the results of commercial catalysts reported so far.

关 键 词：择形催化 ZSM-5 改性 甲苯歧化 对二甲苯 

分 类 号：O643.3[理学—物理化学]