title: Absorption degree analysis on biogas separation with ionic liquid systems.
abstract: For biogas upgrading, present work mainly focuses on either thermodynamics or mass transfer properties. A systematical study on these two aspects is important for developing a new biogas separation process. In this work, a new criterion "absorption degree", which combines both thermodynamics and mass transfer properties, was proposed for the first time to comprehensively evaluate the absorption performance. Henry's law constants of CO2 and CH4 in ionic liquids-polyethylene glycol dimethyl ethers mixtures were investigated. The liquid-side mass transfer coefficients (kL) were determined. The results indicate that IL-NHD mixtures exhibit not only a high CO2/CH4 selectivity, but also a fast kL for CO2 absorption. The [bmim][NO3]+NHD mixtures present a high absorption degree value for CO2 but a low value for CH4. For presenting a highest relative absorption degree value, the 50wt% [bmim][NO3]+50wt% NHD mixture is recommended for biogas upgrading.
authors.affiliation: Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Suojiang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Di
authors.initials: D
authors.lastname: Bao
authors.affiliation: Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: xpzhang@home.ipe.ac.cn.
authors.forename: Xiangping
authors.initials: X
authors.lastname: Zhang
mesh_terms: D056804:Biofuels; D002245:Carbon Dioxide; D052578:Ionic Liquids / Q000737:chemistry*; D007477:Ions; D013816:Thermodynamics
chemical_list: D056804:Biofuels; D052578:Ionic Liquids; D007477:Ions; D002245:Carbon Dioxide
keywords: Absorption degree; Biogas; Ionic liquids; Mass transfer; Thermodynamics