SAPO-18分子筛上二甲醚制低碳烯烃的催化性能研究  

Catalytic Performances of Dimethyl Ether to Olefins over SAPO-18 Molecular Sieves

作　　者：徐淑慧 苏安银 徐照龙 郭朝光 张晓龙 李全发 于建强[1] 

机构地区：[1]青岛大学纤维新材料与现代纺织重点实验室,青岛大学化学化工与环境学院,青岛 [2]久泰能源集团科研中心,临沂

出　　处：《化学工程与技术》2012年第2期48-52,共5页Hans Journal of Chemical Engineering and Technology

基　　金：山东省科技攻关课题(2009GG10007010);国家重大基础研究(973)计划(No.2009CB220000);催化基础国家重点实验室开放基金(No.N-06-18);无机合成与制备化学国家重点实验室开放基金等科研经费的资助。

摘　　要：在固定床反应器上考察了SAPO-18和金属改性的SAPO-18分子筛催化剂上二甲醚制低碳烯烃反应的催化性能。结果表明,金属改性的SAPO-18分子筛结晶度较高。催化反应的最佳反应温度为400℃,最佳空速为DME/N2为10/100 ml/min。在该反应条件下,SAPO-18和RE-SAPO-18上丙烯的选择性总是高于乙烯。金属镍和稀土镧改性的分子筛Ni-SAPO-18和La-SAPO-18的催化性能最好,而稀土铈的添加却降低了SAPO-18的催化活性。在最佳反应条件下,Y-SAPO-18催化剂上DME的转化率达到99.3%,乙烯的选择性达到26.8%,丙烯的选择性为35.0%。The catalytic performance of pure-phase and rare-earth modified silicoaluminophosphate molecular sieves with AEI structures were investigated by dimethyl ether to olefins (DTO) reactions. It demonstrated that the crystallinity of metal modified SAPO-18 molecular sieves is high. For the catalytic reaction, the optimum space velocity is DME/N2 = 10/100 ml/min. Under these conditions, the selectivity toward propylene is always much higher than that of ethylene in both SAPO-18 and RE-SAPO-18 used as catalysts. Moreover, the modification of SAPO-18 by Ni and La improved the catalytic activity, while the modification by Ce has a reverse effect. The catalytic activity and stability were signify- cantly enhanced especially for RE-SAPO-18. The medium acid strength, which was attained in SAPO-18 catalyst, can catalyze DTO reaction more efficiently for improving catalyst lifetime and product selectivity. At the optimum condi- tions, Y-SAPO-18 catalyst gave a DME conversion of 99.3%, together with selectivity to ethylene of 26.8% and pro- pene of 35.0%.

关 键 词：二甲醚 低碳烯烃 磷酸硅铝分子筛 稀土 催化 

分 类 号：O64[理学—物理化学]