催化学报

催化学报

• 研究论文 • 上一篇    下一篇

SAPO-34晶粒形貌对甲醇转化制低碳烯烃反应的影响

吴磊a,b, 刘子玉a, 夏林a, 丘明煌a, 刘旭a, 朱浩佳a, 孙予罕a,c   

  1. a 中国科学院上海高等研究院低碳转化科学与工程中科院重点实验室, 上海201203;
    b 中国科学院大学, 北京100049;
    c 中国科学院山西煤炭化学研究所煤炭转化国家重点实验室, 山西太原030001
  • 收稿日期:2013-01-31 修回日期:2013-03-18 出版日期:2013-07-16 发布日期:2013-07-16
  • 通讯作者: 刘子玉, 孙予罕

Effect of SAPO-34 molecular sieve morphology on methanol to olefins performance

WU Leia,b, LIU Ziyua, XIA Lina, QIU Minghuanga, LIU Xua, ZHU Haojiaa, SUN Yuhana,c   

  1. a CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China;
    c State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
  • Received:2013-01-31 Revised:2013-03-18 Online:2013-07-16 Published:2013-07-16

PDF

1006

被引次数

16

摘要： 分别采用微波和水热法合成了具有片状及立方结构的SAPO-34分子筛.结果发现,片状SAPO-34分子筛晶粒厚度为130nm,比表面积为593m2/g;立方结构SAPO-34分子筛粒径为1.5-2.5μm,比表面积为708m2/g.二者具有数量相近的强酸中心,后者的弱酸位数量略少.甲醇制烯烃反应结果表明,在450℃和1.0h-1的反应条件下,片状SAPO-34分子筛的催化寿命可达380min,乙烯选择性最高为51.77%,乙烯、丙烯及丁烯的总选择性最高为90.20%;而立方结构SAPO-34的催化寿命仅为212min,乙烯选择性最高为49.84%,乙烯、丙烯及丁烯的总选择性最高只有86.81%.这可能源于片状晶粒的扩散路径较短,抑制了低碳烯烃的进一步转化及积碳的生成,因此具有较高的低碳烯烃选择性及较长的寿命.

关键词: SAPO-34分子筛, 形貌, 甲醇制烯烃, 反应温度, 空速

Abstract: SAPO-34 molecular sieve samples with sheet-like and cubic morphology were synthesized under microwave and hydrothermal conditions, respectively. The sheet-like SAPO-34 was 130 nm thick with a Brunauer-Emmett-Teller (BET) surface area of 593 m2/g, while the cubic sample was 1.5-2.5 μm in size with a BET surface area of 708 m2/g. Both samples exhibited a similar density for strong acid sites, while the cubic SAPO-34 possessed less weak acid sites. A methanol to olefins catalytic test carried out at 450 ℃ and 1.0 h-1 showed that the sheet-like SAPO-34 exhibited a long stability life of 380 min and gave a high ethylene selectivity of 51.77% and a high total selectivity for ethylene, propylene, and butylene of 90.20%. However, the stability life for the cubic SAPO-34 was only 212 min, and the ethylene selectivity and total selectivity for ethylene, propylene, and butylene decreased to 49.84% and 86.81%, respectively. It is thought that the longer stability life and higher olefin selectivity for sheet-like SAPO-34 occur because of the shorter diffusion path that hinders the further conversion of produced olefins and coke formation.

Key words: SAPO-34 molecular sieve, Morphology, Methanol to olefins, Reaction temperature, Space velocity