催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (12): 1889-1900.DOI: 10.1016/S1872-2067(11)60454-3

• 研究论文 • 上一篇    下一篇

盐酸溶液和水热脱铝 HEU-1 分子筛的表征及其催化裂解性能

刘晓玲 1, 王艳 1, 王旭金 1, 张亚飞 1, 巩雁军 1,*, 徐庆虎 1,2, 徐君 3, 邓风 3, 窦涛 1   

  1. 1 中国石油大学 (北京)重质油国家重点实验室, CNPC 催化重点实验室, 北京 102249; 2 中海油新能源投资有限责任公司, 北京 100016; 3 中国科学院武汉物理与数学研究所, 湖北武汉430071
  • 收稿日期:2012-07-20 修回日期:2012-08-21 出版日期:2013-01-18 发布日期:2012-12-18

Characterization and Catalytic Performance in n-Hexane Cracking of HEU-1 Zeolites Dealuminated Using Hydrochloric Acid and Hydrothermal Treatments

LIU Xiaoling1, WANG Yan1, WANG Xujin1, ZHANG Yafei1, GONG Yanjun1,*, XU Qinghu2, XU Jun3, DENG Feng3, DOU Tao1   

  1. 1State Key Laboratory of Heavy Oil Processing, CNPC Key Laboratory of Catalysis, China University of Petroleum-Beijing, Beijing 102249, China; 2China National Offshore Oil Corporation New Energy Investment Co., Ltd., Beijing 100016, China; 3Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, Hubei, China
  • Received:2012-07-20 Revised:2012-08-21 Online:2013-01-18 Published:2012-12-18

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摘要： 采用 HCl 溶液和/或水热处理 HEU-1 分子筛, 利用 X 射线衍射、N2 吸附-脱附、X 射线荧光光谱、NH3 程序升温脱附、吡啶吸附傅里叶变换红外光谱和铝固体核磁共振等对脱铝处理的 HEU-1 分子筛进行了表征, 并考察了脱铝 HEU-1 分子筛上正己烷的催化裂解性能. 结果表明, 采用 HCl 溶液处理 HEU-1 分子筛, 能有效脱除非骨架铝, 可调变样品的弱酸中心; 而水热处理 HEU-1 分子筛, 能有效脱除骨架铝, 可调变样品的强酸中心. 水热处理和 HCl 溶液处理有效结合可以达到同时调变 HEU-1 分子筛的酸类型和酸密度的目的. 脱铝 HEU-1 分子筛上正己烷催化裂解反应结果表明, 氢转移反应被明显抑制, 丙烯选择性提高. 600 °C 水热处理后再用 HCl 溶液处理的 HEU-1 分子筛于 625 °C 反应时丙烯选择性由未改性的 21.9% 提高到 35.2%, 活性稳定性也由不足 10 h 提高到 40 h.

关键词: HEU-1 分子筛, 脱铝, 水热处理, 盐酸溶液处理, 催化裂解, 丙烯

Abstract: A series of modified HEU-1 zeolites were prepared using hydrochloric acid treatment, hydrothermal treatment, and a combination of these. The parent and modified HEU-1 zeolites were characterized by X-ray diffraction, N2 adsorption-desorption isotherms, X-ray fluorescence, temperature-programmed desorption of ammonia, Fourier-transform infrared spectroscopy of adsorbed pyridine, and 27Al solid-state magic-angle spinning nuclear magnetic resonance techniques. The catalytic cracking performances of the modified HEU-1 zeolites were evaluated on a fixed-bed microreactor at 625 °C, atmospheric pressure, and an n-hexane weight hourly space velocity of 2.0 h−1. The results showed that extra-framework alumina could be removed by directly treating with hydrochloric acid, and framework alumina could be removed by hydrothermal treatment. Acidity characterization showed that the weak acid sites of HEU-1 zeolites could be adjusted using acid treatment, and the number of strong acid sites could be reduced using hydrothermal treatment. The framework nSi:nAl ratio was improved by using a combination of hydrothermal treatment and acid leaching. The acidities of the HEU-1 zeolites were adjusted and both the mesopore volume and external surface area were enhanced. In n-hexane cracking reactions, the dealuminated HEU-1 zeolite obtained by hydrothermal treatment for 4 h at 600 °C and then washing with hydrochloric acid exhibited the highest propylene production as a result of suppression of the hydrogen transfer reaction. At 625 °C, the selectivity for propylene on HEU-1(HT4-HCl) increased to 35.2% from 21.9%, and the lifetime of HEU-1(HT4-HCl) was also prolonged from not more than 10 to 40 h.

Key words: HEU-1 zeolite, dealumination, hydrothermal treatment, hydrochloric acid treatment, catalytic cracking, propylene