An improved electrochemical model for the NH3fed proton conducting solid oxide fuel cells at intermediate temperatures

Meng Ni, Dennis Y C Leung, Michael K H Leung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

32 Citations (Scopus)

Abstract

An improved electrochemical model is developed to study the ammonia fed solid oxide fuel cell based on proton conducting electrolyte (SOFC-H). Including the chemical reaction kinetics of NH3catalytic thermal decomposition, the present model can be used to predict the performance of the NH3fed SOFC-H at an intermediate temperature (i.e. 773 K). Comparison between the simulation results using the present model and experimental data from literature validates the accuracy of this model. Parametrical analyses reveal that at a high operating temperature (i.e. 1073 K), the NH3fuel is completely decomposed to H2and N2within a very thin layer (30 μm) near the anode surface of an SOFC-H. It is also found that operating the NH3fed SOFC-H at an intermediate temperature of 773 K is feasible due to sufficiently high rate of NH3decomposition. However, further decreasing the temperature to 673 K is not recommended as less than 10% NH3fuel can be decomposed to H2and N2in the SOFC-H. The effects of current density and electrode microstructure on the performance of the NH3fed SOFC-H are also studied. It is found that increasing electrode porosity and pore size is beneficial to increase the partial pressure of H2at the anode-electrolyte interface. The model developed in this paper can be extended to 2D or 3D models to study practical tubular or planar SOFCs.
Original languageEnglish
Pages (from-to)233-240
Number of pages8
JournalJournal of Power Sources
Volume185
Issue number1
DOIs
Publication statusPublished - 15 Oct 2008
Externally publishedYes

Keywords

  • Ammonia catalytic decomposition
  • Ammonia fuel
  • Electrochemical model
  • Mass transfer
  • Proton conducting ceramics
  • Solid oxide fuel cell (SOFC)

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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