As global competition for hydrogen mobility technology for carbon neutrality is fierce, expectations are high that the hydrogen engine technology for passenger cars that uses 100% hydrogen as fuel has been developed for the first time in Korea, which will lead to immediate carbon neutrality for internal combustion engine vehicles.

A joint research team including Senior Researcher Choi Young of the Mobility Power Research Lab at the Korea Institute of Machinery and Materials (President Park Sang-jin) under the Ministry of Science and ICT and Research Fellow Baek Hong-gil of the Decarbonization Engine Research Lab at Hyundai-Kia Motors (Chairman Chung Eui-sun) developed a ‘direct injection hydrogen engine’ that uses 100% hydrogen fuel, and proved its world-class excellence through performance evaluations.

The joint research team of Korea Institute of Machinery and Materials and Hyundai Motor Company directly injected hydrogen into the combustion chamber of an existing Hyundai Motor Company hybrid vehicle engine at a pressure 30 times higher than atmospheric pressure and used a turbocharger to enhance engine performance, thereby maintaining high thermal efficiency in all areas from start-up to when the engine load increases, thereby achieving stable operation.


The existing 'port injection hydrogen engine' had problems such as reduced efficiency due to reduced air intake into the combustion chamber caused by the space occupied by the gaseous hydrogen fuel, and reduced engine performance due to backfire between the hydrogen fuel and air.

On the other hand, the 'direct injection hydrogen engine' developed by the research team directly injects high-pressure hydrogen fuel into the combustion chamber, so it fundamentally solves the backfire problem.It was solved by maximizing thermal efficiency through high compression ratio, fuel stratification, and ultra-lean combustion, while improving output performance and reducing harmful emissions at the same time.

The hydrogen engine developed this time can reduce carbon dioxide (CO2) emissions by 99% and fine dust emissions by 90% compared to gasoline engines, which satisfies the European zero-emission vehicle standards. In addition, it emits nitrogen oxides (NOx) below 15 ppm without an after-treatment device to purify automobile exhaust gas, and achieves a high thermal efficiency of up to 40%.

Choi Young, head of the Mobility Power Research Lab at the Korea Institute of Machinery and Materials, said, “The developed hydrogen engine technology is significant as an immediate and economical technology that can replace fossil fuels used as the main power source for automobiles with carbon-free hydrogen fuel.” He continued, “Through collaboration with Hyundai Motor Company, we will verify durability and expand its application beyond passenger vehicles to commercial vehicles and power generation powertrains. In addition, we will take the lead in realizing carbon neutrality through continuous research and development of carbon-free fuel power technology.”

Meanwhile, this study was conducted with the support of the basic project of the Korea Institute of Machinery and Materials, ‘Development of Liquid Hydrogen Engine for Drone and Robot Drive’ and the ‘Evaluation of Hydrogen Direct Injection Engine Targets’ supported by Hyundai Motor Company.