Engineers successfully adapted a diesel engine to run as a hydrogen-diesel hybrid engine, lowering CO2 emissions by more than 85 per cent.
The Hydrogen-Diesel Direct Injection Dual-Fuel System, which enables existing diesel engines to run using 90 per cent hydrogen as fuel, was developed by the team, under the direction of Professor Shawn Kook from the School of Mechanical and Manufacturing Engineering at the University of New South Wales (UNSW) Sydney, over the course of about 18 months.
According to the experts, the new hybrid system may eventually be retrofitted to any diesel engine used in trucks and equipment utilised in the transportation, agriculture, and mining industries in just a few months.
Diesel is far less eco-friendly than green hydrogen, which is created utilising clean, renewable energy sources like wind and solar.
“This new technology significantly reduces CO2 emissions from existing diesel engines, so it could play a big part in making our carbon footprint much smaller, especially in Australia with all our mining, agriculture, and other heavy industries where diesel engines are widely used,” Professor Kook said.
Professor Kook stated that the team have demonstrated that it is possible to take the current diesel engines and turn them into cleaner, hydrogen-fuelled engines.
“Being able to retrofit diesel engines that are already out there is much quicker than waiting for the development of completely new fuel cell systems that might not be commercially available at a larger scale for at least a decade. With the problem of carbon emissions and climate change, we need some more immediate solutions to deal with the issue of these many diesel engines currently in use,” Professor Kook added.
The UNSW team’s fix for the issue keeps the original diesel injection in the engine but also adds a direct injection of hydrogen fuel into the cylinder.
In a joint study with Dr. Shaun Chan and Professor Evatt Hawkes, it was discovered that precisely timed hydrogen direct injection regulates the mixture condition inside the engine’s cylinder, eliminating the harmful nitrogen oxide emissions that have been a significant barrier to the commercialisation of hydrogen engines.
“If you just put hydrogen into the engine and let it all mix together you will get a lot of nitrogen oxide (NOx) emissions, which is a significant cause of air pollution and acid rain,” Professor Kook said.
According to Professor Kook, they have demonstrated that by stratifying our system so that certain places have more hydrogen than others, we can lower the NOx emissions below those of a diesel engine alone.
Importantly, the Hydrogen-Diesel Direct Injection Dual-Fuel System does not necessitate the use of exceptionally pure hydrogen, which is required in alternative hydrogen fuel cell systems and is more expensive to generate.
In addition, the diesel-hydrogen hybrid outperforms existing diesel engines in terms of efficiency by more than 26 per cent.
This increased efficiency is accomplished through separate management of hydrogen direct injection timing as well as diesel injection timing, allowing full control of combustion modes – premixed or mixing-controlled hydrogen combustion.
The research team hopes to commercialise the new system over the next 12 to 24 months and is eager to meet with potential investors.
According to the researchers, the new technology’s greatest immediate potential application is in industrial settings where permanent hydrogen fuel supply lines are already in place.
This includes mining sites, where studies have found that diesel engines, primarily in mining vehicles and power generators, account for approximately 30 per cent of greenhouse gas emissions.
Furthermore, UNSW said the Australian market for diesel-only power generators is now valued at $765 million.
“At mining sites, where hydrogen is piped in, we can convert the existing diesel engines that are used to generate power. In terms of applications where the hydrogen fuel would need to be stored and moved around, for example in a truck engine that currently runs purely on diesel, then we would also need to implement a hydrogen storage system to be integrated into our injection system,” Professor Kook stated.
Professor Kook believes that the overall technology for mobile hydrogen storage needs to be improved because it is now rather difficult.
