摘要
为进一步优化甲苯与重芳烃烷基转移的反应性能,提高苯产品纯度,同时获得较高的二甲苯产物收率,以Pt/MOR为上层催化剂和ZSM-5分子筛为下层催化剂的复合床反应工艺应用于甲苯与重芳烃烷基转移反应过程。研究了下层催化剂酸性及上下床层催化剂比例对产物结构及苯产品纯度的影响。结果表明,采用复合床体系能有效提高苯纯度,同时保持较高的二甲苯收率。提高下层分子筛酸性有利于产物苯纯度提高。随着下层催化剂比例增加,重芳烃转化率及二甲苯收率下降,同时苯收率及苯纯度提高。在不同床层比例下,反应温度均影响产物苯纯度及产品分布。对复合床反应过程进行了分析,并提出了反应过程模型。该反应工艺可应用于现有甲苯歧化与烷基转移反应装置中,并能有效改善其反应性能及产品质量。
The dual-bed catalyst system, comprised of Pt/MOR as top bed catalyst and ZSM-5 acidic zeolite as bottom bed catalyst, was applied in transalkylation of toluene with heavy aromatics to improve the product purity and xylene yield. The effects of zeolite acidity, the ratio of catalyst in the dual bed and reaction temperature on the composition distribution and benzene purity in product were investigated. The results showed that high purity of benzene as well as high yield of xylene in product could be achieved through the optimization of ratio of two catalyst beds in the dual-bed system. Strong acid site of zeolite in the bottom bed was benefit to benzene purity. Heavy aromatic conversion as well as xylene yield decreased with the rise of bottom bed catalyst ratio, but the benzene yield and purity increased with that. Reaction temperature has a significant effect for all bed ratio system on the product distribution as well as benzene purity. A reaction model was also proposed for the dual-bed system, and this dual-bed system is an effective way to improve reaction performance of the transalkylation of toluene with heavy aromatics.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2013年第4期352-357,共6页
Chemical Reaction Engineering and Technology
关键词
烷基转移
复合床
苯纯度
二甲苯
加氢
非芳裂解
transalkylation
dual-bed system
benzene purity
xylene
hydrogenation
naphthene-crack
