It’s a known fact that diesel engines are more efficient than the gasoline ones, and that is because they work a little differently on the ignition side. Diesel engines compress the fuel to a point where it heats and explodes, a process known as self-ignition. On the other hand, diesel engines are still polluting the atmosphere.
The BMW Group Forschung und Technik, along with some researchers in Graz and Vienna, Austria, have developed a hydrogen-powered combustion engine by using the diesel technology. The project is called “H2BVplus”, and their results were very good, reaching 42% efficiency and competing with the highly efficient classic diesels.
Because hydrogen is a clean-burning gas no limitations regarding particulate emissions have to be taken into account, so the engine can have a stoichiometric fuel mixture (the optimum amount of hydrogen and oxygen for them to recombine into water).
The newly-designed engine is said to be even more efficient than the hydrogen powered Otto models in the past, and the diesel-like approach gives it extra safety, avoiding backfiring or knocking. Anyway, igniting the diesel by pressure is harder to obtain, but researchers say they managed to get pressures of up to 300 bar (30 MPa) in the combustion chamber.
Hydrogen is one of the best options we have for our cars, but its real usefulness largely depends on its extraction point. If it’s from a renewable resource, it’s ok, if it’s from fossil fuel, it’s not. But, for the moment, it’s good to know we have more than one option, even if burning hydrogen is not the most efficient method to move around.