Hydrogen is another alternate fuel tried for IC engines. Investigations were carried out extensively in many countries. The most attractive features of hydrogen as an IC engine fuel are that it can be produced from a potentially available raw material, water and the main product of its combustion again is water.
Disadvantages of using hydrogen as a fuel :
- The requirement of heavy, bulky fuel storage both in the vehicle and at the service stations.
- Hydrogen can be stored either as a cryogenic liquid or as a compressed gas. If stored as a liquid, it would have to be kept under pressure at a very low temperature requiring a thermally super-insulated fuel tank.
- Storing in a gas phase would require a high-pressure vessel with limited capacity.
- Hydrogen is difficult to refuel.
- Possibility of detonation.
- Poor engine volumetric efficiency.
- Fuel cost would be high at present-day technology because costly to produce.
- Also the problem of availability of hydrogen.
- Hydrogen fuel ignites very easily and therefore the design of fuel intake was done with at most care.
- It may not be toxic but it is flammable for sure. This would add unnecessarily and new risk into society.
- While hydrogen is an alternative fuel, a disadvantage is that it still has a dependency on coal, oil, and natural gas.
The automobile company Mazda has adapted a rotary Wankel engine to run on hydrogen fuel. this car uses a metal hybrid fuel storage system.