UNSW Syndey group develops hydrogen-diesel twin gas system; 90% H2, greater than 85% discount in CO2


Engineers from UNSW Sydney (Australia) have efficiently transformed a diesel engine to run as a dual-fuel hydrogen-diesel engine, decreasing CO2 emissions by greater than 85% in comparison with typical diesel. The group, led by Professor Shawn Kook from the Faculty of Mechanical and Manufacturing Engineering, spent round 18 months creating the Hydrogen-Diesel Direct Injection Twin-Gasoline System that enables current diesel engines to run utilizing 90% hydrogen as gas.


The researchers say that any diesel engine utilized in vehicles and energy tools within the transportation, agriculture and mining industries may in the end be retrofitted to the brand new hybrid system in simply a few months.

In a paper revealed within the Worldwide Journal of Hydrogen Vitality, Prof. Kook’s group reveals that utilizing their patented hydrogen injection system reduces CO2 emissions to only 90 g/kWh—85.9% under the quantity produced by the diesel powered engine.

Excessive indicated imply efficient stress (IMEP) of as much as 943 kPa and 57.2% indicated effectivity was achieved at 90% hydrogen vitality fraction, on the expense of NOx emissions. The hydrogen injection timing instantly controls the combination situation and combustion mode. Early hydrogen injection timings exhibited premixed combustion behaviour whereas late injection timings produced mixing-controlled combustion, with an intermediate level reached at 40 °CA bTDC hydrogen injection timing.

At 90% hydrogen vitality fraction, the sooner injection timing results in greater IMEP/effectivity however the NOx enhance is inevitable because of enhanced premixed combustion. To maintain the NOx enhance minimal and obtain the identical combustion phasing of a diesel baseline, the 40 °CA bTDC hydrogen injection timing reveals one of the best efficiency at which 85.9% CO2 discount and 13.3% IMEP/effectivity enhance are achieved.

—Liu et al.


The Hydrogen-Diesel Direct Injection Twin-Gasoline System options impartial management of hydrogen direct injection timing, in addition to diesel injection timing, enabling full management of combustion modes: premixed or mixing-controlled hydrogen combustion. Picture from Prof. Shawn Kook

The UNSW group’s answer to the issue maintains the unique diesel injection into the engine, however provides a hydrogen gas injection instantly into the cylinder.

The brand new Hydrogen-Diesel Direct Injection Twin-Gasoline System doesn’t require extraordinarily excessive purity hydrogen which should be utilized in various hydrogen gas cell programs and is costlier to provide.

The analysis group hope to have the ability to commercialize the brand new system within the subsequent 12 to 24 months and is eager to seek the advice of with potential traders. The researchers say probably the most fast potential use for the brand new expertise is in industrial places the place everlasting hydrogen gas provide traces are already in place.

That features mining websites, the place research have proven that about 30% of greenhouse-gas emissions are brought on by means of diesel engines, largely in mining automobiles and energy turbines. The Australian marketplace for diesel-only energy turbines is at present estimated to be value round $765 million.


  • Xinyu Liu, Gabrielle Seberry, Sanghoon Kook, Qing Nian Chan, Evatt R. Hawkes (2022) “Direct injection of hydrogen predominant gas and diesel pilot gas in a retrofitted single-cylinder compression ignition engine,” Worldwide Journal of Hydrogen Vitality, doi: 10.1016/j.ijhydene.2022.08.149


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