title: Efficient utilization of greenhouse gases in a gas-to-liquids process combined with CO2/steam-mixed reforming and Fe-based Fischer-Tropsch synthesis.
abstract: Two process models for carbon dioxide utilized gas-to-liquids (GTL) process (CUGP) mainly producing light olefins and Fischer-Tropsch (F-T) synthetic oils were developed by Aspen Plus software. Both models are mainly composed of a reforming unit, an F-T synthesis unit and a recycle unit, while the main difference is the feeding point of fresh CO2. In the reforming unit, CO2 reforming and steam reforming of methane are combined together to produce syngas in flexible composition. Meanwhile, CO2 hydrogenation is conducted via reverse water gas shift on the Fe-based catalysts in the F-T synthesis unit to produce hydrocarbons. After F-T synthesis, the unreacted syngas is recycled to F-T synthesis and reforming units to enhance process efficiency. From the simulation results, it was found that the carbon efficiencies of both CUGP options were successfully improved, and total CO2 emissions were significantly reduced, compared with the conventional GTL processes. The process efficiency was sensitive to recycle ratio and more recycle seemed to be beneficial for improving process efficiency and reducing CO2 emission. However, the process efficiency was rather insensitive to split ratio (recycle to reforming unit/total recycle), and the optimum split ratio was determined to be zero.
authors.affiliation: Research Center for Green Catalysis, Korea Research Institute of Chemical Technology (KRICT) , Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Chundong
authors.initials: C
authors.lastname: Zhang
authors.forename: Ki-Won
authors.initials: KW
authors.lastname: Jun
authors.forename: Kyoung-Su
authors.initials: KS
authors.lastname: Ha
authors.forename: Yun-Jo
authors.initials: YJ
authors.lastname: Lee
authors.forename: Seok Chang
authors.initials: SC
authors.lastname: Kang
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis; D002245:Carbon Dioxide / Q000737:chemistry*; D015392:Chemistry, Inorganic / Q000379:methods*; D017752:Greenhouse Effect; D006838:Hydrocarbons / Q000138:chemical synthesis*; D006859:Hydrogen / Q000737:chemistry; D006865:Hydrogenation; D007501:Iron / Q000737:chemistry*; D008697:Methane / Q000138:chemical synthesis; D008962:Models, Theoretical; D009821:Oils / Q000138:chemical synthesis; D059027:Recycling; D013227:Steam; D013696:Temperature
chemical_list: D000475:Alkenes; D006838:Hydrocarbons; D009821:Oils; D013227:Steam; D002245:Carbon Dioxide; D006859:Hydrogen; D007501:Iron; D008697:Methane