Fuel cells are being considered seriously as a potential replacement for internal combustion engines in buses, vans, and ultimately passenger cars. Concern for air quality in urban areas, the possibility of better fuel efficiency, and the prospect of using coal- or biomass-derived alcohols rather than imported oil as fuel are the major motivations. The challenges are to reduce the capital cost of the fuel cell systems and to adapt them for automative use. This study was conducted to make a preliminary comparison of the major types of fuel cells for vehicle propulsion applications. Simplified schematic flow sheets were devised for different fuel cell types. These flow sheets were then used for thermodynamic analyses. Other factors investigated include startup, transient response capability, and system complexity, but no attempt was made to analyze system behavior with reference to any specific driving cycle. For these analyses, fuel cell systems of 60 kWe (gross) were used, equivalent to the approx. 55 kWe battery systems required for advanced electric vans. Four fuel cell types were considered in this study: phosphoric acid (PAFC), proton exchange membrane (PEM), molten carbonate (MCFC), and monolithic acid oxide (MSOFC). Although an experimental van has been successfully operated with an alkaline fuel cell on bottled hydrogen fuel in Europe, this type of fuel cell was not considered in this study. In our view, the alkaline fuel cell is not compatible with alcohol fuels because of the CO2.
Presented at the 11th Fuel Cell Seminar on Development and Application of Fuel Cells for the 90s
- Pub Date:
- Cost Analysis;
- Fuel Cells;
- Motor Vehicles;
- Electronics and Electrical Engineering