SOFC Modeling at the Cell Scale including Hydorgen and Carbon Monoxide as Electrochemically Active Fuels
Författare
Summary, in English
Fuel cells are promising for future energy systems, because they are energy efficient and able to use renewable fuels. A fully coupled computational fluid dynamics (CFD) approach based on the finite element method (with the software COMSOL Multiphysics) in two-dimensions is developed to describe an intermediate temperature solid oxide fuel cell (SOFC) single cell. Governing equations covering heat, gas-phase species, momentum, ion and electron transport are implemented and coupled to kinetics describing internal reforming and electrochemical reactions. Both hydrogen and carbon monoxide are considered as electrochemically active fuels within the anode.
The activation polarization in the electrodes and the ohmic polarization due to ion transport in the YSZ material are found to be the major part of the potential losses. The activation polarization is the most significant and it is smaller within the cathode compared to the anode for this study. The ion current density and the activation polarization are the highest at the electrolyte-electrode interface and decrease rapidly within the electrodes as the distance from the interface increases. However, the ohmic polarization by ion transfer increases for the positions away from the interface. The addition of the electrochemical reaction with CO as fuel increases the current density. It is concluded that the temperature and current density are strongly integrated and when any of them is changed, the other follows, and the change is accelerated.
The activation polarization in the electrodes and the ohmic polarization due to ion transport in the YSZ material are found to be the major part of the potential losses. The activation polarization is the most significant and it is smaller within the cathode compared to the anode for this study. The ion current density and the activation polarization are the highest at the electrolyte-electrode interface and decrease rapidly within the electrodes as the distance from the interface increases. However, the ohmic polarization by ion transfer increases for the positions away from the interface. The addition of the electrochemical reaction with CO as fuel increases the current density. It is concluded that the temperature and current density are strongly integrated and when any of them is changed, the other follows, and the change is accelerated.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Sidor
281-291
Publikation/Tidskrift/Serie
ASME FuelCell
Dokumenttyp
Konferensbidrag
Förlag
American Society Of Mechanical Engineers (ASME)
Ämne
- Energy Engineering
Nyckelord
- SOFC
- Modeling
- Electrochemical reactions
- Hydrogen
- Carbon monoxide
- Cell scale
- 2D
Conference name
ASME 2012 Tenth International Fuel Cell Science, Engineering, and Technology Conference FuelCell2012
Conference date
2012-07-23 - 2012-07-26
Conference place
San Diego, CA, United States
Status
Published
ISBN/ISSN/Övrigt
- ESFuelCell2012-91112