【摘要】 采用低分子季铵碱(或盐)、低分子醇或氢氧化铵为阳离子成功地合成了ZSM-5型沸石。这些沸石的主要物性数据与文献值基本一致,但它们在用于甲醇转化为烃的反应中性能差别较大。初步考察了沸石的硅铝比和晶粒大小对甲醇转化的影响,发现沸石的平均晶粒约大于7μ或硅铝比高于150左右时表现出对于二甲苯异构体有择形作用,产物中对位二甲苯量超过热力学平衡值。此外,还考察了操作参数与沸石催化性能的关系。更多还原

【Abstract】 Several samples of ZSM-5 type zeolites have been synthesized by using lower quaternary ammonium hydrate (or ammonium salts) lower alcohols and even ammonium hydroxide as cations respectively. Their chief physico-chemical characteristic data are found closely in agreement with those given in literatures, but their behavior toward methanol conversion are rather different. A preliminary investigation of the effects of Si/Al ratio and crystal particle size upon the methanol conversion has been carried out. It has been shown that in case of the average crystal size greater than 7μ or Si/Al ratio higher than 150, an obvious shape selectivity in xylene fraction can be observed.The content of the p-xylene is much higher than the thermodynamic equillibrium value.Besides, the effects of process variables on the catalytic behavior of the different zeolites synthesized are evaluated.更多还原