ZSM-5硅铝比对甲醇制丙烯反应产物的影响  

Effect of Si/Al Ratio in ZSM-5 on the Selectivity of Products for Methanol Conversion to Propylene

作　　者：温鹏宇[1] 梅长松[2] 刘红星[2] 杨为民[2] 陈庆龄[1] 

机构地区：[1]华东理工大学化学与制药学院,上海200213 [2]中国石油化工股份有限公司上海石油化工研究院,上海201208

出　　处：《化学反应工程与工艺》2007年第5期385-390,共6页Chemical Reaction Engineering and Technology

基　　金：国家重点基础研究规划(973计划;2003CB615801)

摘　　要：采用红外光谱、X射线衍射、扫描电子显微镜、电感耦合等离子体焰炬(ICP)元素分析、氮低温吸附和吡啶红外等表征手段对合成的不同硅铝比ZSM-5催化剂进行了表征,并在微分反应器中考察了沸石硅铝比对甲醇制丙烯反应中丙烯收率和丙烯-乙烯质量比(P/E)的影响。结果表明,随着硅铝比增加,丙烯收率先升后降而乙烯收率则持续下降。机理分析表明,丙烯的稳定性低于乙烯是导致产物丙烯收率随催化剂酸性降低先升后降而乙烯收率连续下降的原因,是影响P/E比的关键因素。硅铝比为120的ZSM-5催化剂具有质量分率34.3%的丙烯收率,丙烯-乙烯质量比达到4.1,若要进一步提高丙烯收率和P/E比,需从其他方面(如扩散性能改善)对催化剂进行改性。The as-synthesized ZSM-5 zeolites with different Si/AI ratios and the similar particle sizes were characterized by infrared （IR）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, inductively coupled plasma （ICP）, N2-adsorption and Py-IR techniques. The methanol conversion reactions over these catalysts were carried out in a micro-reactor and the influence of Si/Al ratio in ZSM-5 on the propylene yields and the ratios of propylene to ethylene （P/E） were investigated. It was showed that the yield of ethylene decreased but the propylene yield increased first and then decreased as the Si/Al increased. And the kinetics analysis showed that the less stability of propylene than ethylene was the determinant for such phenomena. The propylene mass yield of 34.3% and P/E ratio of 4.1 were obtained over ZSM-5 with Si/Al ratio of 120. Other kind of modification on ZSM-5 was needed for the purpose of further increasing propylene yields and P/E ratios.

关 键 词：甲醇 丙烯 乙烯 ZSM-5催化剂 反应选择性 

分 类 号：O643[理学—物理化学]