【作者】 慕俊娟；

【导师】 李建伟；

【作者基本信息】 北京化工大学 ， 化学工艺， 2004， 硕士

【摘要】 基于改性(、MCM-22和混合型沸石催化剂，开展了苯与乙烯液相烷基化合成乙苯反应过程的研究，并基于性能评价和特性表征相结合的方式，对三种催化剂性能差异的原因进行了探讨。文中，首先针对改性(沸石催化剂，以单因素实验和正交实验相结合的方式，系统考察了反应条件对烷基化反应过程的影响。结果表明，改性(催化剂上乙苯合成的适宜反应条件为：温度 180~220oC、苯/乙烯摩尔比 6~8、乙烯质量空速(2.5h-1，在此条件下，乙烯转化率在98%以上，且催化剂具有较好的活性稳定性；在所考察的实验范围内，C10~C13和稠环芳烃的含量处于较低水平，而严重影响乙苯产品质量的二甲苯和副产物三乙苯的含量均处于极低水平。以性能评价（活性、选择性和稳定性）和特性表征（XRD、TPD、FTIR和孔结构测定）相结合的方式，对上述三种催化剂性能比较的结果表明：（1）改性(的活性明显高于MCM-22，但乙苯选择性却低于MCM-22绝对差约3%；（2）改性(上二乙苯和其他副产物的生成量分别约为MCM-22上对应值的1.7和1.5倍左右；（3）混合型催化剂的性能与改性(相仿，但乙苯选择性提高0.5%左右；（4）对乙苯合成，沸石催化剂的活性主要取决于其B酸中心数、酸强度及酸分布，产物分布则取决于催化剂表面的乙苯脱附能垒值和孔道结构，而稠环芳烃的生成量和催化剂孔道结构是影响催化剂稳定性的主要因素。更多还原

【Abstract】 The reaction process of benzene alkylation with ethylene to form ethylbenzene was investigated under liquid-phase reaction conditions over zeolites modified β, MCM-22 and their mixture, and the performance differences among these catalysts were also investigated combining the catalytic reaction experiments and the characterization of the catalysts.At first, the effect of reaction conditions on the alkylation process for ethylbenzene synthesis over the modified β zeolite catalyst was systematically discussed and the optimal reaction conditions were researched by means of the single factor and orthogonal experiments The result shows that the appropriate operating conditions are as follows: temperature 180~220℃, benzene/ethylene molar ratio 6~8 and the weight hourly space velocity of ethylene ≤2.5h-1. Under these conditions, the ethylene conversion is more than 98.0% and the catalyst has good activity stability. In the liquid-phase products, the mounts of the by-products (C10~C13 and poly-ring aromatic alkyate) are lower, and the dimethylbenzene, which will seriously affect the quality of ethylbenzene product, and the triethylbenzene were not been detected.Combining the performance evaluation (activity, selectivity and <WP=5>stability) and the characterization of the catalysts (XRD, TPD, FTIR and the pore structure measure), it can be concluded that : (1)The activity of modified β is higher than MCM-22, but the selectivity of ethylbenzene is lower about 3% than that of MCM-22; (2)The mounts of diethylbenzene and the other by-products are higher 1.7 times and 1.5 times than these of MCM-22 respectively; (3)The catalytic performance of zeolite mixture is nearly equal to modified β, but the selectivity of ethylbenzene is higher about 0.5% than that of modified β; (4)The catalytic activity of zeolite is mainly correlated with the number of acid sites, strength and distribution, and the distribution of products is determined by the binding energy of ethylbenzene and the pore structure, while the stability of catalyst is affected by the amount of poly-ring aromatic alkylate and the pore structure.更多还原