The EU does not want to allow any new combustion engines from 2035. This increases the need for alternatives suitable for the masses. MAN, for example, wants to convert trucks to hydrogen.
Even if the performance of rechargeable batteries for electric cars has improved in recent years, battery-related issues often remain reasons for skepticism towards electric cars. Short ranges, long charging times and a lack of charging infrastructure cause at least 60 percent of those surveyed to worry, as a representative survey by the Institute for Demoscopy (IfD) Allensbach on behalf of acatech – German Academy of Science and Engineering – found.
Even if researchers and manufacturers try to dispel consumers’ skepticism about e-cars, it should be justified at the latest when it comes to trucks. The reason: They are much heavier and also cover much longer distances than cars. An electric motor is out of the question here. However, environmentally harmful diesel drives are also not the solution due to the climate crisis – especially in light of the fact that the EU Commission has even spoken out in favor of a ban on internal combustion engines from 2035.
Hydrogen therefore seems to be the magic word – as is the case with some train, tram and car manufacturers: The truck manufacturer MAN, for example, would like to convert diesel to hydrogen – but with an alternative to the fuel cell.
Hydrogen without fuel cells: MAN relies on hydrogen engines
In addition to the fuel cell, MAN relies on the hydrogen engine – a combination of hydrogen drive and combustion engine, as the Frankfurter Allgemeine Zeitung (FAZ) reports. The hydrogen engine is available more quickly: “In 2030, hydrogen combustion engines will have the same life cycle costs as today’s diesel engines,” said Lukas Walter from MAN to the FAZ. The prerequisite for this is that the price for green hydrogen falls by then.
To convert the drive, MAN increased the engine displacement from 15.2 liters to 16.8 liters in order to counteract the lower power density in hydrogen operation, according to FAZ. That was not entirely successful, because the nominal output is still around 100 kilowatts lower. But 80 percent of the components remained unchanged in this way, which keeps the effort and thus the costs of the retrofitting as low as possible. According to the FAZ report, MAN plans to install the drive in a TGX series truck this year and test it on the road.
The supplier Bosch is also working on hydrogen technology: The company is working on 79 projects worldwide in which the potential of the combination of hydrogen combustion and reciprocating engines is being researched, as Andreas Kufferath from Bosch told FAZ.
Hydrogen drive: fuel cells should be produced more cheaply
A possible problem with the combination of combustion and hydrogen are the high temperatures during combustion, as this promotes the formation of nitrogen oxides. According to Kufferath, however, the raw engine emissions in front of the exhaust system are already below the current limit values that apply to the entire vehicle with exhaust gas cleaning.
With a simplified catalytic converter system, nitrogen oxide emissions can also be reduced to nine milligrams per kilometer, as Marc Sens from engineering service provider IAV estimated in the FAZ. “This means that such an engine has practically no influence on the local air quality”, says Sens.
In the meantime, work is also being carried out on inexpensive production of fuel cells. According to FAZ, Christian Mohrdieck from Cellentric expects that inexpensive fuel cell drives will be available by the end of this decade at the latest. They are working on automating the production of the cells. It remains to be seen whether it will be clarified by then to what extent one can hope for green hydrogen for road traffic. (ial)
