MHIET confirms stable combustion of hydrogen admixture through testing of single cylinder engine

Mitsubishi Heavy Industries Engine & Turbocharger (MHIET), a part of Japan’s Mitsubishi Heavy Industries (MHI) Group, has confirmed stable combustion of hydrogen admixture through a testing of a single cylinder engine.

Courtesy of MHI

MHIET revealed the test achieved stable combustion with up to 50 vol% hydrogen admixture without losing the rated output, adding it was performed aiming for altering the KU series gas engine cogeneration system, a widely used system in various industries, into a system of less carbon emissions while maintaining output.

To note, in preparation for targeted commercialization in FY2025, MHIET said the company will finalize specifications of auxiliary equipment to be installed together with the engine and control systems of all related equipment.

In this testing, according to MHIET, the team tackled issues such as engine knocking caused by hydrogen’s faster flame propagation speed and preignition combustion caused by lower minimum ignition energy of hydrogen and succeeded in maintaining stable combustion by adjusting the excess air ratio and other parameters.

Consequently, the team verified stable combustion of hydrogen admixture of a maximum of 50 vol% while keeping the rated output. This suggests the cogeneration system with the original 5.75 MW engine would generate the same result, MHIET noted.

Furthermore, the testing revealed that the cogeneration system that generates power and steam is likely to satisfy a CO2 emission coefficient of 0.27kg- CO2/kWh without recovering energy for hot water, the company pointed out, adding that the emission level is set as the standard for natural gas-fired power generation system during transitional period by EU taxonomy for sustainable activities. The team expects that the CO2 emission coefficient of this system specification will be further reduced by fueling hydrogen blend, and they continue to work on the development, MHIET said.

As mentioned above, the KU series gas engine cogeneration system has been used by many customers all over the world. The modification to GSI, retrofitting with an updated ignition system, can bring higher energy efficiency and lower CO2 emission, MHIET claimed, noting that, likewise, the new installation of GSI would make it easier to rework for hydrogen blend fuel.

MHIET further said the company will expedite marketing of KU and other gas engine products that are fueled by hydrogen mixture or pure hydrogen, to offer expanded options to achieve low carbon or zero carbon society.

Click here to read more about hydrogen projects in Japan.