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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (15): 1810-1814. 上一篇    下一篇

研究论文

苯与丙烯在β分子筛上吸附行为的蒙特卡罗研究

孙晓岩 李建伟* 李英霞 陈标华

  

  1. (北京化工大学化工资源有效利用国家重点实验室 北京 100029)

  • 投稿日期:2007-11-02 修回日期:2008-03-03 发布日期:2008-08-14
  • 通讯作者: 李建伟

Adsorption of Benzene and Propene in β Zeolite by Grand Canonical Monte Carlo Simulation

SUN, Xiao-Yan LI, Jian-Wei* LI, Ying-Xia CHEN, Biao-Hua   

  1. (State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China)
  • Received:2007-11-02 Revised:2008-03-03 Published:2008-08-14
  • Contact: LI, Jian-Wei

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被引次数

38 | 5

采用巨正则统计系综蒙特卡罗模拟方法研究了β分子筛上苯与丙烯分子的吸附行为. 由分子筛内吸附质粒子云分布可知, 在100 kPa时, 丙烯在分子筛上的吸附量要远远大于苯的吸附量. 由吸附相互作用能分布来看, 苯与分子筛之间相互作用能比丙烯与分子筛之间的相互作用能更负, 这就使苯分子的吸附相对于丙烯分子稳定. 相对而言, 温度变化对丙烯吸附影响远大于对苯吸附的影响, 如100 kPa时, 温度由298 K升高至443 K导致丙烯分子吸附量明显减少, 由每8个晶胞吸附98个丙烯分子减少到80个; 而对苯分子吸附却没有显著的影响. β分子筛上存在着苯和丙烯的竞争吸附, 并且吸附分子之间存在相互作用使两者与分子筛之间的相互作用能分布改变. 在压力范围1×10－3～5.0 kPa, 不同温度下苯与丙烯在分子筛内吸附等温线的模拟结果表明, 在较高温度、较低压力下丙烯的吸附量要小于苯的吸附量.

关键词: β分子筛, 巨正则统计系综蒙特卡罗模拟, 吸附

The adsorption behavior of benzene and propene in β zeolite has been studied by grand canonical Monte Carlo (GCMC) simulations. From the mass clouds of GCMC simulations, it can be found that the benzene and propene molecules show different adsorption behavior in the zeolite cavities. The loadings of propene are significantly larger than those of benzene at 100 kPa. From the figures of potential energy distribution, the potential energy of propene and zeolite is higher than that of benzene and zeolite, so benzene can adsorb more stably than propene. When the temperature rose from 298 to 443 K at 100 kPa, the number of propene was reduced from 98 to 80, while benzene changed little. When benzene and propene adsorbed in zeolite at the same time, there are competitive adsorption, therefore the potential energy distribution could be changed significantly. The adsorption isotherms of benzene and propene at different temperatures and 1× 10－3～5.0 kPa show that at low pressure and high temperature, the loadings of propene are significantly lower than those of benzene.

Key words: β zeolite, grand canonical ensemble Monte Carlo simulation, adsorption