Engineers at the University of New South Wales say they have successfully modified a conventional diesel engine to use a mix of hydrogen and a small amount of diesel, claiming their patented technology has cut carbon dioxide emissions by more than 85%.

The university trials involve mounting a hydrogen direct injection system into existing diesel engines.

It has been claimed that what makes the university’s system unique, is the way it mixes the hydrogen and diesel and then introduces it to the engine cylinder for combustion.

Unlike fossil fuels, hydrogen does not produce carbon dioxide when burnt, so it has long been seen as a greener fuel source.

About 90% of fuel in the hybrid diesel engine is hydrogen but it must be applied in a carefully calibrated way because doing it incorrectly has the potential of an explosive mix that could burn out the whole system.

According to the university, studies have shown that controlling the mixture of hydrogen and air inside the cylinder of the engine can help negate harmful nitrogen oxide emissions, which have been an obstacle to the commercialisation of hydrogen motors.

The researchers believe diesel trucks and power equipment in the mining, transportation and agriculture sectors could now be retrofitted with the new hybrid system.

The concept is for a hybrid engine to run off a hydrogen-diesel mix or, in the absence of hydrogen, it can revert to diesel only.

Commercial production of the new generation engine is believed possible within two years.

Tim Buckley, the director at Climate Energy Finance, a public interest think-tank in Sydney, has been quoted as saying that the technology has the potential to transform the major user of diesel, Australian mining industry dramatically.