Abandoned for a few years, the idea of adapting internal combustion engines to use hydrogen as fuel is picking up again. Led by a former BMW, the Munich start-up Keyou even proposes to adapt diesels to the use of this ultra-widespread gas on earth.
In the early 2000s, very special 7 Series E65s crisscrossed the roads around the world. Their particularity? Their V12 used hydrogen as fuel. But, by giving up gasoline, the noble twelve-cylinder then fell from 445 to 260 hp, and BMW had finally abandoned the development of this technology. Today, however, we find one of the engineers who participated in this project, Thomas Korn, at the head of a Munich start-up, Keyou, who still believes in this solution.
This young company has even just converted two large diesel vehicles to the use of this gas: an 18 t truck and a 12 m city bus. These two utilities, powered by the same 7.8 l engine developing approximately 272 hp, will thus be able to begin a test phase. Confident, the company is already announcing total costs close to those of a diesel, a lifespan of more than 700,000 km, a range of more than 500 km. All this without CO emissions2 or particles in the exhaust. With hydrogen, only water vapor would be released at this level.
Simpler than the fuel cell
The approach differs somewhat from that of Toyota, which favored sports vehicles, even competition, initially powered by gasoline. The manufacturer first took as a base the three-cylinder of the GR Yaris, then the naturally aspirated Lexus V8 revisited by Yamaha. But the Japanese giant and the German start-up agree on one point: the idea of using hydrogen (H2) as fuel in a heat engine, with limited modifications. It is for this same purpose that the equipment manufacturer BorgWargner unveiled in February a complete system for injecting H2 “rapidly marketable, which requires only slight adaptations of the traditional internal combustion engine”.
A major advantage compared to the complex and expensive fuel cell of a Toyota Mirai, a Hyundai Nexo or certain Stellantis and Renault utilities. In this case, in fact, the hydrogen is only used to produce electricity through a reaction with the oxygen in the air, in order to drive an electric motor. As for lithium-ion batteries, the most popular alternative today, they are penalized in certain uses by their recharging times, their weight or their size.
Still obstacles to overcome
Still, the game is far from a foregone conclusion for this apparently quite simple technology. For it to be considered sufficiently virtuous, it would indeed be imperative that the necessary hydrogen be produced in a clean manner, using renewable energies. However, it‘is unfortunately far from being the rule today, since the two most commonly used techniques use natural gas or oil. If it is possible to extract the hydrogen present naturally in water thanks to a process called electrolysis, it is also much more expensive and it requires a lot of electrical energy. The distribution and storage of H2, which is highly flammable and has a very low bulk density, also causes some difficulties. For the time being, even if it seems to be arousing more and more interest, the use of hydrogen must therefore still prove that it can really constitute a viable alternative to the “all-electric” that the European Union would like to impose. from 2035 in its quest for carbon neutrality.
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