HZSM-5／Hβ复合分子筛的正辛烷临氢异构化和芳构化性能.pdfVIP

第36卷第2期 燃 料 化 学 学 报 VoI．36 NO．2 2008年4月 Journal of Fuel Chemistry and Technology Apr．2008 文章编号：0253-2409(2008)02—160-06 HZSM-5／HI3复合分子筛的正辛烷临氢异构化和芳构化性能 张振莉，周亚松，李长喜，徐春明 (中国石油大学(北京)重质油国家重点实验室，北京 102249) 摘 要：将不同孔尺寸、酸强度的HZSM-5和HI3分子筛混合制得复合载体，担载金属组分Ni、Mg、Mo、Zn制得烷烃异构化和 芳构化催化剂M／C。采用XRD、BET、程序升温氨脱附(NH3-TPD)及吡啶吸附一脱附红外光谱法对制备的载体及催化剂进行 了理化性质表征。以正辛烷为正构烷烃模型化合物，在连续加氢微型反应装置上评价了催化剂对正构烷烃异构化和芳构化 反应的催化性能。结果表明，与单一分子筛相比，复合后载体的表面酸中心分布得到了调节，中强酸中心的增加有利于烷烃 异构化和芳构化反应。复合分子筛催化剂引入不同金属组分进行改性后体现出不同的催化性能，其中Ni的引入既提供了加 脱氢活性中心，又获得了适宜的B、L酸中心分布，使反应转化率和选择性显著提高。反应条件对催化剂的异构化和芳构化性 能也有不同程度的影响，在320℃、2．8 IVIPa、2．0 h 下，正辛烷的临氢异构化和芳构化选择性较好。 关键词：复合分子筛；酸性；正辛烷；临氢异构化；临氢芳构化 中图分类号：TE624 文献标识码：A Hydroisomerization and aromatization of，l-octane over HZSM-S／Hg_, composite zeolite ZHANG Zhen—li，ZHOU Ya—song，LI Chang-xi，XU Chun—ming (State Key Laboratory ofHeavy Oil Processing，China University ofPetroleum(Beijing)，Beijing 102249，China) Abstract：Bifunctional catalysts( C)were prepared by impregnating different metals(M)on composite zeolite(C)of HZSM．5 and H13 with different acidities and pore sizes．The physicochemical characteristics of the supports and catalysts were characterized by XRD，NH3一TPD and physical adsorption．The catalytic performance ofⅣI／，C in hydroisomerization and hydroaromatization was evaluated in a micro．reactor with octane as model compound．The results showed that the composite zeolite C had appropriate distribution of acidity which was beneficial to isomerization and aromatization of octane．The hydrogenation active sites could be Offered and the Bronsted and Lewis acid distribution in the catalysts could be adjusted by the modification with metal like Ni． which could enhance the hydroisomerization and hydroaromatization of octane．The hydroisomeriz