化工学报 ›› 2013, Vol. 64 ›› Issue (11): 4082-4089.DOI: 10.3969/j.issn.0438-1157.2013.11.027

• 分离工程 • 上一篇    下一篇

真实吸附溶液理论预测CH4-C2H6在活性炭上的吸附平衡

李明, 涂适, 赵欣, 刘龑   

  1. 同济大学化学系, 上海 200092
  • 收稿日期:2013-03-25 修回日期:2013-06-06 出版日期:2013-11-05 发布日期:2013-11-05
  • 通讯作者: 李明
  • 作者简介:李明(1972-),男,副教授。
  • 基金资助:

    国家自然科学基金项目(20506019);中央高校基本科研业务费专项资金项目。

Adsorption equilibrium prediction for CH4-C2H6 on activated carbon by real adsorption solution theory

LI Ming, TU Shi, ZHAO Xin, LIU Yan   

  1. Department of Chemistry, Tongji University, Shanghai 200092, China
  • Received:2013-03-25 Revised:2013-06-06 Online:2013-11-05 Published:2013-11-05
  • Supported by:

    supported by the National Natural Science Foundation of China(20506019)and the Fundamental Research Funds for the Central Universities.

摘要: 采用容积法测试了纯CH4和C2H6在204-Ⅱ活性炭上的吸附等温线,温度为293 K,压力范围为0~4 MPa。采用捕集法测试了CH4-C2H6混合体系293 K、0~1.1 MPa条件下在204-Ⅱ活性炭上的吸附平衡数据,其中CH4浓度范围34.0%~95.2%。引入描述吸附相自身非理想性的真实吸附溶液模型(RAST),结合描述吸附剂表面势场不均一的孔径分布模型(MPSD),建立了MPSD-RAST模型,其中RAST模型中的活度因子使用Wilson方程和NTRL方程计算。采用MPSD-RAST模型对CH4-C2H6吸附平衡数据进行了预测,并与理想吸附溶液模型(IAST)和MPSD-IAST模型进行了对比分析。结果表明,对于轻组分CH4,MPSD-RAST模型预测平衡吸附量和摩尔分数的精度明显优于IAST和MPSD-IAST模型;对于重组分C2H6,IAST、MPSD-IAST和MPSD-RAST 3种模型的预测偏差均低于5%。研究结果表明,预测混合气体的吸附平衡,吸附相自身非理想性是必须考虑的重要因素。

关键词: 混合气体, 吸附平衡, 吸附相, 非理想性, 活度因子, 模型

Abstract: Adsorption equilibrium of pure methane and ethane on activated carbon 204-Ⅱ was determined by the volumetric method at 293 K and 0-4 MPa.Adsorption data,with the CH4 concentration in the range of 34.0%-95.2%,were measured by the open flow method on activated carbon 204-Ⅱ at 293 K.The real adsorption solution theory(RAST)expressing the non-ideality of the local adsorbed phase was combined with the micro-pore size distribution(MPSD)model describing the energetic distribution of the adsorbent surface,and a MPSD-RAST model was put forward to predict adsorption equilibrium of binary CH4-C2H6 system.The Wilson equation and the NTRL equation were adopted to calculate activity coefficients for the local adsorbed phase.The ideal adsorption solution theory(IAST)and the MPSD-IAST model were also used for prediction.The investigation demonstrates that the MPSD-RAST model greatly improves prediction accuracy of the adsorption amount and the mole fraction for CH4,compared with the IAST and MPSD-IAST models.For the heavy component C2H6,prediction deviations with these three methods are all lower than 5%.It is important to consider non-ideality of the adsorbed phase in prediction models.

Key words: gas mixture, adsorption equilibrium, adsorbed phase, non-ideality, activity coefficient, model

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