Selection of Fuel Cells
The selection of a fuel cell is mainly based on the following factors :
- Cost
- Size/volume of cell
- Availability of fuel and its heat
- Transportability.
- Hydrocarbons like methane, ethane, and propane gases are not used since they are less reactive and their oxidation in fuel cell is difficult. Therefore, these fuels are not suitable for use in fuel cells.
- Thus, most of the fuels which can be used in fuel cells are H2, NH3, CH3, OH (Methanol), N2H4,(Hydrazine), CO etc. Out of these fuels, hydrogen is the best fuel since its heat of reaction per kg of fuel is highest amongst all the fuels. Thus, fuel cells based on hydrogen -O2/air are best suited for applications like spacecraft, submarines etc.
- Fuels like ammonia, methanol and hydrazine are reasonably reactive and can be conveniently used in fuel cells. Ammonia is toxic. Hydrazine is toxic, poisonous and does not require any catalyst.
- Though the ammonia is cheaper than hydrazine but it is comparatively less reactive.
- Therefore, hydrazine is quite suitable for use in fuel cells particularly for military applications. On the other hand, NH, being cheap and easily available, it is suitable for remote area and low power applications.