能源化学(英文版)

能源化学(英文) ›› 2019, Vol. 28 ›› Issue (2): 50-57.DOI: 10.1016/j.jechem.2018.02.003

• Preface • 上一篇    下一篇

Fe-substituted Ba-hexaaluminate with enhanced oxygen mobility for CO2 capture by chemical looping combustion of methane

Fei Huanga,b, Ming Tianb, Yanyan Zhuc, Xiaodong Wangb, Aiqin Wangb, Lin Lib, Jian Linb, Junhu Wangb   

  1. a Fujian Normal University, Fuzhou 350007, Fujian, China;
    b State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    c College of Chemical Engineering, Northwest University, Xi'an 710069, Shaanxi, China
  • 收稿日期:2018-01-03 修回日期:2018-01-24 出版日期:2019-02-15 发布日期:2019-02-15
  • 通讯作者: Ming Tian, Xiaodong Wang
  • 基金资助:

    This work was supported by the National Science Foundation of China (NSFC) (21303137, 21406225 and 21676269), the National Key Project for Fundamental Research and Development of China (2016YFA0202801) and Postdoctoral Science Foundation of China (2014M561261).

Fe-substituted Ba-hexaaluminate with enhanced oxygen mobility for CO2 capture by chemical looping combustion of methane

Fei Huanga,b, Ming Tianb, Yanyan Zhuc, Xiaodong Wangb, Aiqin Wangb, Lin Lib, Jian Linb, Junhu Wangb   

  1. a Fujian Normal University, Fuzhou 350007, Fujian, China;
    b State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    c College of Chemical Engineering, Northwest University, Xi'an 710069, Shaanxi, China
  • Received:2018-01-03 Revised:2018-01-24 Online:2019-02-15 Published:2019-02-15
  • Contact: Ming Tian, Xiaodong Wang
  • Supported by:

    This work was supported by the National Science Foundation of China (NSFC) (21303137, 21406225 and 21676269), the National Key Project for Fundamental Research and Development of China (2016YFA0202801) and Postdoctoral Science Foundation of China (2014M561261).

摘要： While Fe-based oxygen carriers (OC) are regarded to be promising for chemical looping combustion (CLC), the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur after multiple redox cycles due to the low oxygen mobility. Herein, Fe-substituted Bahexaaluminates (BaFexAl12-xO19, denoted as BFxA-H, x=1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen (Ot) and CH4 conversion (77% and 81% vs. 17% and 75%) than those prepared by the traditional co-precipitation method (BFxA-C, x=1 and 2) but also high CO2 selectivity above 92% during the nearly whole reduction from Fe3+ to Fe2+. Furthermore, the BFxA-H exhibited the excellent recyclability during 50 cycles. The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites (Fe5:71% and 70% vs. 49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe5 (O-Fe5) (0.45 and 0.85 mmol/g vs. 0.31 and 0.50 mmol/g). The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step, resulting in the excellent recyclability of BFxA-H.

关键词: CO2 capture, Chemical looping, CH4 conversion, Oxygen mobility, Fe-based hexaaluminate

Abstract: While Fe-based oxygen carriers (OC) are regarded to be promising for chemical looping combustion (CLC), the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur after multiple redox cycles due to the low oxygen mobility. Herein, Fe-substituted Bahexaaluminates (BaFexAl12-xO19, denoted as BFxA-H, x=1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen (Ot) and CH4 conversion (77% and 81% vs. 17% and 75%) than those prepared by the traditional co-precipitation method (BFxA-C, x=1 and 2) but also high CO2 selectivity above 92% during the nearly whole reduction from Fe3+ to Fe2+. Furthermore, the BFxA-H exhibited the excellent recyclability during 50 cycles. The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites (Fe5:71% and 70% vs. 49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe5 (O-Fe5) (0.45 and 0.85 mmol/g vs. 0.31 and 0.50 mmol/g). The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step, resulting in the excellent recyclability of BFxA-H.

Key words: CO2 capture, Chemical looping, CH4 conversion, Oxygen mobility, Fe-based hexaaluminate