Reforming of biogas using electrochemical cell

DOI Web Site Web Site 8 Citations 26 References
  • HIRATA Yoshihiro
    Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University
  • MATSUNAGA Naoki
    Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University
  • SAMESHIMA Soichiro
    Department of Chemistry, Biotechnology, and Chemical Engineering, Kagoshima University

Search this article

Abstract

This review reports the recent research results of solid oxide fuel cells using biogas (typical composition, 60% CH4–40% CO2), reforming of CH4 with CO2 (CH4 + CO2 → 2CO + 2H2) and shift reaction of CO with H2O (CO + H2O → H2 + CO2). Solid oxide fuel cells using dense yttria-stabilized zirconia and gadolinium-doped ceria electrolytes were operated with biogas containing CH4 of 7–63 vol % at 630–875°C. A maximum power density of 20–160 mW/cm2 was measured and this value was 1/10–1/3 of that for the cells with a H2 fuel. The reforming of CH4 with CO2 proceeds over a Ni-based catalyst at 700–900°C to produce a H2–CO fuel. The carbon deposition due to the pyrolysis of CH4 as a parallel reaction is suppressed by addition of second phase such as K2O or Ru to Ni catalyst. Electrochemical reforming of CH4 with CO2 using a porous Gd-doped ceria (GDC) cell is an attractive process to produce a H2–CO fuel at 400–800°C. The supplied CO2 is changed to CO and O2− ions by the reaction with electrons at the cathode (CO2 + 2e− → CO + O2−). The produced CO and O2− ions are transported to the anode through a porous mixed conductor GDC film. In the anode CH4 reacts with O2− ions to produce CO, H2 and electrons (CH4 + O2− → CO + 2H2 + 2e−). This process suppresses the carbon deposition from CH4. Ni in the anode accelerated the pyrolysis of CH4 but Ru promoted the oxidation of CH4 with transported O2− ions. Ni and Ru in the cathode worked well to change CO2 to CO plus O2−. Furthermore, shift reaction of reformed gas with H2O vapor proceeded to produce a H2 fuel using a porous GDC electrochemical cell with Co2O3 catalyst at 400–500°C.

Journal

Citations (8)*help

See more

References(26)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top