ZSM-5分子筛固定床催化合成聚甲氧基二甲醚  

Synthesis of polyoxymethylene dimethyl ethers with shaped ZSM-5 catalysts in a fixed-bed reactor

作　　者：雷骞[1,2] 梁琳琳 吕高孟 陈洪林[1,2] LEI Qian;LIANG Linlin;LYU Gaomeng;CHEN Honglin(Chengdu Institute of Organic Chemistry,Chinese Academy of Sciences,Chengdu 610041,Sichuan,China;Chengdu Zhongke Catalysis Technology Company Limited,Chengdu 610041,Sichuan,China)

机构地区：[1]中国科学院成都有机化学研究所,四川成都610041 [2]成都中科凯特科技有限公司,四川成都610041

出　　处：《化工进展》2022年第4期1908-1915,共8页Chemical Industry and Engineering Progress

基　　金：国家重点研发计划(2018YFB0604900)。

摘　　要：通过X射线衍射(XRD)、扫描电子显微镜(SEM)、氨气程序升温脱附(NH_(3)-TPD)和吡啶吸附-红外光谱(Py-IR)等对不同硅铝比(SiO_(2)/Al_(2)O_(3))的ZSM-5分子筛粉末催化剂进行表征。在间歇反应器中,本文对比了不同硅铝比ZSM-5分子筛粉末催化三聚甲醛和甲缩醛合成聚甲氧基二甲醚(PODE)的催化活性,结果表明硅铝比为400的ZSM-5分子筛粉末具有最高的PODE_(2~8)的收率和选择性。然后,采用挤条成型法,在ZSM-5分子筛粉末(SiO_(2)/Al_(2)O_(3)=400)中加入硅溶胶黏结剂和甲基纤维素黏结剂,制备得到ZSM-5成型催化剂,硅溶胶添加量和甲基纤维素分子量影响成型催化剂强度。采用ZSM-5成型催化剂,以固定床为反应器,反应温度和反应空速在所考察的范围内对三聚甲醛(TOX)的转化率和PODE的选择性影响较小。在85℃、压力1MPa、空速为5h^(-1)的条件下进行了240h催化性能考察,成型催化剂催化性能稳定,三聚甲醛的转化率高于90%,PODE_(2~8)的选择性达到95%以上。The ZSM-5 zeolite powders with different silica/alumina ratios(SiO_(2)/Al_(2)O_(3))were characterized by XRD,SEM,NH_(3)-TPD and Py-IR.The catalytic performance of the ZSM-5 zeolites was compared in the synthesis of polyoxymethylene dimethyl ethers(PODE)from trioxane and methylal in a batch reactor.The ZSM-5 catalyst with SiO_(2)/Al_(2)O_(3) molar ratio of 400 showed the highest yield and selectivity of PODE_(2-8).Then,the extruded ZSM-5 catalyst were prepared from the ZSM-5 powder(SiO_(2)/Al_(2)O_(3)=400)by adding silica sol and methyl cellulose as binder.The mechanical strength of the extruded ZSM-5 catalyst was influenced by the adding amount of silica sol and the molecular weight of methyl cellulose.The extruded ZSM-5 catalyst were used to synthesize PODE in a fixed-bed reactor.Temperature and space velocity had little effect on the conversion of trioxane and the selectivity of PODE under the conditions examined.When the reaction temperature was 85℃and space velocity was 5h-1 in the fixed-bed reactor,the extruded ZSM-5 catalyst showed excellent stability in a 240h test,and the conversion of trioxane was higher than 90%,and the selectivity of PODE_(2~8) was above 95%.

关 键 词：聚甲氧基二甲醚 合成 分子筛 催化剂 固定床 

分 类 号：O643[理学—物理化学]