Advances in sustainable mobility are increasingly surprising and promising. We are living in a stage where we no longer have to choose between a powerful engine and an emission-free one. This has been made possible in large part thanks to the development of hydrogen as a fuel, which has made it possible for a French company to design the first CO2-neutral five-stroke engine.
France creates first five-stroke engine: runs on hydrogen and emits no CO2
Hydrogen continues to gain increasing relevance as a fuel for the mobility of the future, as it offers three times more energy capacity than hydrocarbons and the only by-product it emits is water vapor. Moreover, it can be used in combustion engines, including competitive engines such as the hydrogen racing car developed by Toyota.
The hydrogen industry is growing rapidly in Europe, driven by the need to move away from dependence on fossil fuels and position itself in a market that will be key to the vehicles of the future. While currently the biggest obstacle is the lack of infrastructure for storage, distribution and marketing, it is only a matter of time before this is resolved.
For France, it is a fact that in the future hydrogen propulsion will be an everyday occurrence, which is why it has taken the hydrogen engine to a new level. The company EHM has recently presented a new model that incorporates a fifth stage to the combustion cycle to take advantage of the residual energy dissipated after completing each cycle, significantly increasing efficiency.
Unexpected innovation: more power and performance with the same amount of fuel
A four-stroke engine works, as its name suggests, by means of four-stage cycles: first air and fuel are injected into the cylinder; then the piston compresses the mixture; then the spark from the spark plug produces an explosion that is boosted by the compression; the cycle is completed with the exhaust of the gases to start a new cycle.
During the exhaust phase, along with the waste gases, a residual percentage of energy is also expelled. EHM has been studying for some time a way to harness this residual energy to increase fuel efficiency. The solution? Adding a fifth stage in which the water vapor emitted after combustion is sent to a second cylinder.
Although the French firm has not provided further details on the technology that makes this revolutionary improvement possible, they have five patents that support the feasibility of their invention. According to the data collected during the tests performed for this hydrogen engine, they would have managed to increase the efficiency from 37% of conventional engines to 50%.
What plans does EHM have for its five-stroke hydrogen engine?
The company has already started procedures to raise investors. The initial goal is to raise 100 million euros in three years to start the production phase. The first stage would start with 3500 units per year to increase this volume up to 9000. They would have a power output of 360 hp and would be intended for heavy-duty vehicles such as garbage and heavy-duty trucks.
Developing an engine of this type implies the difficulty of not being able to adapt the technology to existing propellants, although this does not seem to be a problem for the French, who hope to install a plant in Châteaulin, Finistère, which would employ some 50 people.
A clean fuel with infinite possibilities
The hydrogen engine has potential for a myriad of applications thanks to its energy efficiency and its ability to power vehicles by emitting water vapor free of harmful gases. Technologies ranging from large transport ships to flying cabs capable of traveling 800 km are being studied.