Equilibria in Fuel Cell Gases

Abstract

Because chemical compositions in thermodynamic equilibrium for various fuel gases are specified by the ratios among carbon, hydrogen, and oxygen, carbon-hydrogen-oxygen (C-H-O) ternary diagrams are useful to present relevant operational conditions of fuel cells. Such C-H-O ternary diagrams are constructed, describing the carbon deposition region, the fuel gas region, partial pressures of gaseous species including O2, H2, and CO, and electromotive force corresponding to the theoretical open circuit voltage of fuel cells. Such ternary diagrams present these operational conditions for any given C-H-O ratios without any additional calculations. ©2003 The Electrochemical Society. All rights reserved.