By Teun Schröder Scientists at the University of New South Wales (UNSW) in Australia have converted a diesel engine with minimal modifications so that it can also run on hydrogen. The research shows that a rapid switch to a more sustainable fuel is possible, provided that the hydrogen is green, of course. In technology it is called a retrofit: adding new technology to existing systems, so that machines are given new possibilities. In this case, the scientists added a hydrogen injection system to a diesel engine. This allows the engine to run on a mixture of 90 percent hydrogen and 10 percent diesel. The results were published in the International Journal of Hydrogen Energy. Although the fuel mixture cannot therefore be called completely clean, CO2 emissions fell by 85 percent compared to a completely diesel mixture. In addition, scientists reported an improvement in efficiency of 26 percent. Diesel and hydrogen injection The engine still uses a diesel injection, but is supplemented by a hydrogen injection that is directly connected to the cylinder. Both injection systems are controlled separately. This makes it possible to play with the amount of hydrogen in the cylinder. The result of this is a lot less nitrogen emissions than when a mixture of diesel and hydrogen ends up in the cylinder at the same time. Of course, hydrogen must be made with renewable energy to be labeled as a sustainable fuel. That rarely happens now. The vast majority of hydrogen is still produced from fossil fuels. Making mining more sustainable Nevertheless, the scientists already see opportunities for their innovation, for example for heavy vehicles and generators in mines. “At mine sites where hydrogen is already being supplied, we can convert existing diesel generators that are used to generate electricity,” says Professor Shawn Kook, one of the lead researchers. Quick solution “Being able to retrofit diesel engines that are already on the market is much faster than waiting for completely new fuel cell systems to be developed, which may be a decade away,” says Kook. “Due to carbon emissions and climate change, we need more immediate solutions to address the problem of the many diesel engines currently in use.”