title: Adsorption of CO₂, CH₄, and N₂ on ordered mesoporous carbon: approach for greenhouse gases capture and biogas upgrading.
abstract: Separation of CO₂ and N₂ from CH₄ is significantly important in natural gas upgrading, and capture/removal of CO₂, CH₄ from air (N₂) is essential to greenhouse gas emission control. Adsorption equilibrium and kinetics of CO₂, CH₄, and N₂ on an ordered mesoporous carbon (OMC) sample were systematically investigated to evaluate its capability in the above two applications. The OMC was synthesized and characterized with TEM, TGA, small-angle XRD, and nitrogen adsorption/desorption measurements. Pure component adsorption isotherms of CO₂, CH₄, and N₂ were measured at 278, 298, and 318 K and pressures up to 100 kPa, and correlated with the Langmuir model. These data were used to estimate the separation selectivities for CO₂/CH₄, CH₄/N₂, and CO₂/N₂ binary mixtures at different compositions and pressures according to the ideal adsorbed solution theory (IAST) model. At 278 K and 100 kPa, the predicted selectivities for equimolar CO₂/CH₄, CH4/N₂, and CO₂/N₂ are 3.4, 3.7, and 12.8, respectively; and the adsorption capacities for CH₄ and CO₂ are 1.3 and 3.0 mmol/g, respectively. This is the first report of a versatile mesoporous material that displays both high selectivities and large adsorption capacities for separating CO₂/CH₄, CH₄/N₂, and CO₂/N₂ mixtures.
authors.affiliation: Chemical Engineering Department, New Mexico State University, Las Cruces, New Mexico 88003, United States.
authors.forename: Bin
authors.initials: B
authors.lastname: Yuan
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wu
authors.forename: Yingxi
authors.initials: Y
authors.lastname: Chen
authors.forename: Jianhan
authors.initials: J
authors.lastname: Huang
authors.forename: Hongmei
authors.initials: H
authors.lastname: Luo
authors.forename: Shuguang
authors.initials: S
authors.lastname: Deng
mesh_terms: D000327:Adsorption; D056804:Biofuels; D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D017752:Greenhouse Effect; D008697:Methane / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D009584:Nitrogen / Q000737:chemistry*; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen; D008697:Methane