Korea Institute of Machinery and Materials, Hyundai and Kia unveil 2L ammonia engine

Direct, high-pressure liquid injection model

Click to learn more. The Korea Institute of Machinery and Materials unveils its 2L, ammonia-fueled engine this month, developed in collaboration with Hyundai and Kia. Source: KIMM.

In collaboration with the Electrification Engineering Center of Hyundai Motor and Kia, the Korea Institute of Machinery and Materials (KIMM) has developed a high-pressure, direct liquid injection engine utilising ammonia fuel. Although the use of gaseous ammonia fuel in combustion engines is a common approach (for instance, in 2 and 4-stroke marine engines), it can result in variable power outputs and increased N₂O/NO_X emissions, and it often requires the use of a small amount of pilot fuel (usually carbon-containing). Direct injection of liquid fuel enables the use of pure ammonia without pilot fuel, achieving a stable power output.

Click to enlarge. Schematic of KIMM’s 2L ammonia-fueled engine. Source: KIMM.

The announcement indicates that the research team enhanced the engine’s performance by improving the ignition system, and has developed a dedicated after-treatment system to minimize NO_X emissions and ammonia slip. In June 2024, KIMM announced that it had developed a MW-scale, LNG-ammonia co-fired engine for maritime applications. This larger marine engine utilises a similar fuel ammonia approach to the new 2L model – injection of high-pressure ammonia fuel directly into the combustion chamber, as well as maximizing thermal efficiency with rich and lean combustion stages. This “two-stage” combustion technique is also a feature of the development of ammonia-fired gas turbines, with IHI Corporation currently scaling up a two-stage combustor unveiled in 2022.

This innovation represents a groundbreaking improvement over conventional ammonia engine technologies, introducing a new concept in power systems.

Principal Researcher Dr. Cheolwoong Park of KIMM, in his organisations’ official press release, 23 Jan 2025

This engine technology could serve as a breakthrough in addressing the challenges of hydrogen transportation and green hydrogen production, establishing ammonia as a new clean fuel-based power solution.

Principal researcher Dr. Seungwoo Lee of Hyundai Motor and Kia, in KIMM’ official press release, 23 Jan 2025