摘要
采用晶种法直接合成了硅铝比(SiO_2/Al_2O_3物质的量比)为137、224和309的三种Al-ITQ-13分子筛,并采用粉末X射线衍射(XRD)、扫描电镜(SEM)、N_2吸附-脱附、固体核磁共振(MAS NMR)和NH_3-程序升温脱附(NH_3-TPD)等分析方法对不同硅铝比分子筛进行了表征,并在固定床微型反应评价装置上,考察了硅铝比对甲醇转化制丙烯反应性能的影响。结果表明,不同硅铝比Al-ITQ-13分子筛呈现出相似的织构性质,酸量及酸强度随着硅铝比的升高逐渐下降。硅铝比对甲醇转化反应的产物分布存在较大的影响;随着硅铝比的升高,氢转移反应和芳构化反应活性降低,使得乙烯选择性下降,而丙烯和丁烯的选择性升高。硅铝比由137提高到309,丙烯的选择性(质量分数)由46.04%增加到55.52%,而丙烯/乙烯比由3.39提高到6.57。
Al-ITQ-13zeolites with different Si02/Al203molar ratios were synthesized by using seeds in the gel and characterized by XRD,SEM,N2physisorption,MAS NMR and NH3-TPD.The effect of Si02/Al203molar ratio on the catalytic performance of Al-ITQ-13in the conversion of methanol to propene(MTP)was investigated in a fixed-bed micro-reactor.The results showed that the Al-ITQ-13zeolites with different Si02/A1203molar ratios are similar in their textural properties;however,the amount and strength of acid sites decrease with the increase of Si02/Al203molar ratio.Moreover,the Si02/Al203molar ratio has a significant influence on the catalytic behavior of Al-ITQ-13in MTP.As the hydrogen transfer and aromatization reactions were suppressed over the Al-ITQ-13zeolite with high Si02/Al203molar ratio,with the increase of Si02/Al203molar ratio,the selectivity to propene and butene is increased at the expense of the selectivity to propene;that is,with the increase of Si02/Al203molar ratio from137to309,the selectivity to propene is increased from46.04%to55.52%and meanwhile,the propene/ethene ratio is increased from3.39to6.57.
作者
曾鹏晖
张莉莉
郭小忠
李明富
郭巧霞
牛超
申宝剑
ZENG Peng-hui;ZHANG Li-Ii;GUO Xiao-zhong;LI Ming-fu;GUO Qiao-xia;NIU Chao;SHEN Bao-jian(State Key Laboratory of Heavy Oil Processing,College of Chemical Engineering,College of Sciences,China University of Petroleum (Beijing) , Beijing 102249, China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2017年第11期1349-1355,共7页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(U1462202)
中国石油大学(北京)科研基金(2462015YQ0309)资助~~
作者简介
Corresponding author.Tel：010-89733369，E-mail：baojian@cup.edu.cn.
