Development of catalyst for the synthesis of styrene from ethane and benzene

乙苯合成苯乙烯催化剂的研制

基本信息

批准号：
11650811
负责人：
SUZUKI Toshimitsu
金额：
$ 2.37万
依托单位：
Kansai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

A large quantity of styrene monomer was produced in the world from ethylene and benzene to give ethylbenzene followed by dehydrogenation. 3 step processes were required in the current technology. This project was planned to develop a simple and energy saving chemical process. For this, ethane was used for the alkylation of benzene using various acid catalysts such as zeolite. However, yield of ethylbenzene was very small. Considering that formation of ethyl cation from ethane is difficult, loading of several metal species which are capable of dehydrogenation of alkane was examined.Alkylation of benzene with ethane was carried out using various zeolite catalyst at temperature ranges of 400 to 550℃. Loading of platinum onto zeolite enhanced yield of ethylbenzene greatly. Among zeolite tested, H-ZSM5, H-AlMCM41, and H-MCM22 showed catalytic activities. However, mordenite did not give ethylbenzene. Moderate acid strength distribution is the key factor of zeolite catalyst. Optimum catalyst and conditions for this reaction is as follows :Platinum-loaded H-ZSM5 catalyst containing 6.8 wt % Pt, at the reaction temperature of 500℃, afforded ethylbenzene and styrene formation rates of 14.2 and 0.8 mmol h^<-1>・g^<-1> of catalyst, respectively (benzene-based yields 7.3 and 0.4 %). In the alkylation of benzene with ethane over platinum-loaded H-ZSM5, ethene would be initially formed from ethane over the metallic platinum. Then the alkylation would proceed over the acid sites of H-ZSM5.Dehydrogenation of ethylbenzene was investigated, and found that magnesium oxide-loaded vanadium oxide exhibited very high activity in the presence of carbon dioxide. Carbon dioxide promoted redox cycle of vanadium oxide during dehydrogenation reaction. Where lattice oxygen of vanadium oxide was gradually lost during dehydrogenation, then carbon dioxide reoxidized low valent vanadium oxide to higher valency state.

从乙烯和苯在世界上产生了大量的苯乙烯单体，从而产生乙苯，然后进行脱氢。当前技术需要3个步骤。该项目计划开发一个简单而节能的化学过程。为此，使用各种酸性催化剂（例如沸石）使用了同样的苯饮酒。但是，乙烯的产量很小。考虑到从萨梅烯中形成乙基阳离子是困难的，研究了能够脱氢烷烃的几种金属物种的负载。苯在400至550°的温度范围内使用各种沸石催化剂在温度范围内对苯烯进行苯基化。铂将铂载在沸石上，可大大提高乙烯的产量。在经过测试的沸石中，H-ZSM5，H-ALMCM41和H-MCM22显示出催化活性。但是，灰军没有给出乙烯。中度酸强度分布是沸石催化剂的关键因素。该反应的最佳催化剂和条件如下：铂载的H-ZSM5催化剂含有6.8 wt％Pt，在500°的反应温度下，提供的乙烯苯和苯乙烯的形成速率为14.2和0.8 mmol H^<-1> g^g^<-1> catalyst基于型（benzene），均为4.3和0.4％。在加载铂的H-ZSM5上具有相同苯的烷基化时，乙烯最初是由金属铂的相同形成的。然后，研究了饮酒，在H-ZSM5的酸位点进行。乙烯苯二氢化作用被研究，发现在二氧化碳存在下，氧化镁氧化镁的氧化镁表现出很高的活性。二氧化碳在脱氢反应过程中促进了氧化钒的氧化还原周期。其中，氧化钒的格氧在脱氢过程中逐渐损失，然后二氧化碳将低氧化钒氧化物的低氧化氧化物氧化氧化氧化氧化物氧化氧化氧化氧化氧化氧化物氧化氧化氧化物氧化氧化物氧化较高。