碱金属改性对SAPO.pdf

第66 卷 第4 期 化 工 学 报 Vol.66 No.4 2015 年4 月 CIESC Journal April 2015 碱金属改性对SAPO-34 分子筛催化性能的影响 商红岩，张青青，尤培培，左飞，王玲玲，李昭清，张佳佳，刘晨光 （中国石油大学（华东）CNPC 催化重点实验室，山东 青岛 266580 ） 摘要：通过等体积浸渍法，制备得到碱金属（Li 、Na 、K、Rb 、Cs ）改性的SAPO-34 催化剂。并在常压连续固定 床反应器上评价了各催化剂的甲醇制低碳烯烃（MTO ）的性能，同时对催化剂进行了XRD 、FT-IR 、NH -TPD 等 3 表征分析。结果表明，碱金属负载量为2%时，除Cs 离子改性的催化剂低碳烯烃的选择性和寿命有所降低外，其 他碱金属离子改性的SAPO-34 催化剂低碳烯烃的选择性和寿命都有了明显的提高，尤其是Li 离子改性的催化剂 乙烯+丙烯的选择性达77%左右，寿命相对延长了2.5 倍；将该催化剂再生3 次后乙烯、丙烯的选择性几乎保持不 变。 关键词：等体积浸渍；碱金属；选择性；寿命；再生；催化 DOI ：10.11949/j.issn.0438-1157 中图分类号：O 643 文献标志码：A 文章编号：0438—1157 （2015 ）04—1331—06 Influence of alkali metals-modification on catalytic properties of SAPO-34 SHANG Hongyan, ZHANG Qingqing, YOU Peipei, ZUO Fei, WANG Lingling, LI Zhaoqing, ZHANG Jiajia, LIU Chenguang (Key Laboratory of Catalysis, CNPC, China University of Petroleum, Qingdao 266580, Shandong, China) Abstract: The catalysts prepared by modifying SAPO-34 zeolite with alkali metals(Li, Na, K, Rb, Cs) in the way of incipient-wetness impregnation method were evaluated using methanol-olefin(MTO) reaction in the normal pressure continuous flowing fixed bed reactor. The structures of modified SAPO-34 catalysts were characterized by XRD, FT-IR, NH3-TPD. The results show that lower olefins selectivity and lifetime are improved for 2% alkali-modified SAPO-34, compared with unmodified SAPO-34, except Cs-modified SAPO-34. Ethylene and propylene selectivity of Li-modified SAPO-34 catalyst are about 77% and its lifetime are prolonged by 2.5 times.