The combustion engine still has a future! It is possible to decarbonise this century-and-a-half-old technology by replacing petrol or diesel with hydrogen.
Technically, the conversion of an engine does not require major modifications. As hydrogen is gaseous at ambient temperature and pressure, it is essentially a question of modifying the fuel supply circuit. Direct injection makes it possible to finely dose the distribution of hydrogen (a very expansive gas) to obtain a well-controlled mixture. A safe hydrogen tank must also be installed. After conversion, the vehicle no longer emits CO₂, only a small amount of nitrogen oxide due to the combustion of the hydrogen. Blocks – diesel or petrol – with large displacements are particularly suitable for this transformation as they are robust enough to absorb the stresses of hydrogen.
This solution, which has not yet been approved for use on the road, can only be applied to a vehicle that has been self-certified by its original manufacturer, as is the case for construction equipment, agricultural machinery or even snow groomers (see the off-road section). In the long term, if the regulations evolve, cars, coaches and heavy goods vehicles could also be concerned.