A hydrogen engine is a device that uses hydrogen as fuel to generate mechanical power. In its operation, hydrogen is introduced into a combustion chamber along with oxygen from the air. The mixture produces a chemical reaction that releases a large amount of energy in the form of heat. This heat is converted into mechanical motion, which is used to power a vehicle, generate electricity, or perform other mechanical tasks.
In addition to hydrogen internal combustion engines, there is another important technology in the field of hydrogen-powered vehicles: hydrogen fuel cells. Unlike internal combustion engines, which burn hydrogen directly, hydrogen fuel cells work through an electrochemical reaction between hydrogen and oxygen in the air, without generating polluting emissions.
The highlight is that the abundance of hydrogen on our planet makes this technology an excellent renewable energy source to replace fossil fuels.
Hydrogen as fuel
Hydrogen is presented as an attractive alternative in the search for cleaner and more sustainable fuels. Unlike conventional fossil fuels, when hydrogen is burned, the only byproduct is water, making it an extremely clean and environmentally friendly energy source.
How do hydrogen engines work?
These engines consist of a combustion chamber where hydrogen mixes with oxygen from the air and ignites. The resulting chemical reaction releases energy in the form of heat, which is converted into mechanical energy to propel a vehicle.
In the case of those that use hydrogen fuel cells, hydrogen is introduced into the anode of the cell, while oxygen from the air enters the cathode. In the oxidation process at the anode, electrons are released from hydrogen, creating hydrogen ions and free electrons. These electrons travel through an external circuit, generating electricity that can power an electric motor. Meanwhile, at the cathode, electrons and hydrogen ions combine with oxygen from the air and electrons from the external circuit to form water, the only byproduct of this process.
Advantages
- Zero carbon emissions: As mentioned above, hydrogen engines only emit water when used, meaning they do not contribute to the greenhouse gas emissions that cause climate change.
- Longer range: Hydrogen vehicles often have a longer range compared to battery electric vehicles. This is because hydrogen can be stored more efficiently and recharged more quickly than batteries.
- Fast recharging: Unlike electric vehicles that require time to charge their batteries, hydrogen vehicles can refuel as quickly as a conventional internal combustion vehicle.
- Application Flexibility: Hydrogen engines are not limited to passenger vehicles. They are also suitable for commercial vehicles, trucks, trains and ships, making them a versatile option for decarbonizing transport in different sectors.
Disadvantages
Despite their advantages, hydrogen engines face several major challenges:
- Hydrogen production: Large-scale hydrogen production still relies heavily on non-renewable energy sources, such as natural gas. Procuring green hydrogen, produced from renewable energy sources, is a key challenge that must be overcome.
- Supply infrastructure: For hydrogen vehicles to be viable, adequate supply infrastructure is needed. Currently, this infrastructure is limited compared to the network of electric charging stations.
- Upfront costs: Hydrogen vehicles tend to have a higher upfront price compared to traditional internal combustion vehicles or even electric vehicles.
- Energy Efficiency: The conversion efficiency of hydrogen into mechanical energy is lower compared to electric batteries, resulting in lower overall energy performance.
Recent applications and developments
Additionally, automakers are developing hydrogen vehicles, and logistics companies are testing hydrogen trucks for long-distance deliveries.
One promising growth area is the marine industry, where hydrogen engines are being considered as an alternative to diesel engines in large vessels. This could have a significant impact on reducing emissions in one of the most polluting industries.