A coalition led by the Korea Institute of Machinery and Materials (KIMM), Hyundai Motor, and Kia has developed “the world’s first engine capable of directly injecting ammonia into the combustion chamber at high pressure.” The coalition reported overcoming longstanding challenges in power stability and emissions.
- Direct High-Pressure Injection: The engine eliminates the need for gaseous ammonia reformers or combustion additives, enabling stable power output using pure ammonia. This addresses previous issues of unstable combustion and incomplete fuel utilization.
- Optimized Combustion: The team achieved industry-leading performance metrics by synchronizing multi-stage fuel injection with variable valve timing and enhancing the ignition system.
- Emission Control: A proprietary after-treatment system drastically reduces nitrogen oxides (NOx) and unburnt ammonia emissions, which are critical hurdles to ammonia’s adoption as a clean fuel.
This innovation represents a groundbreaking improvement over conventional ammonia engine technologies, introducing a new concept in power systems.
The research team enhanced the engine’s performance by refining the ignition system and optimizing the timing of fuel injection and valve operation. Additionally, they developed a dedicated after-treatment system to minimize nitrogen oxides (NOx) and unburned ammonia emissions. As a result, the engine exhibited significantly improved thermal efficiency and power output while drastically reducing harmful emissions. These developments suggest the potential of ammonia as a practical and efficient fuel for various applications.
Real-world deployment
The technology is designed for immediate integration into marine propulsion, off-grid power systems, and heavy-duty vehicles. Hyundai/Kia highlighted its potential to “transform regional shipping,” with plans for deployment by 2027. The engine’s compatibility with green ammonia (produced through renewable-powered Haber-Bosch processes) positions it as a scalable technology for industries seeking fuel flexibility amid hydrogen’s storage challenges.
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.
Look out, fossil fuels
Ammonia’s high energy density (18.6 MJ/L) and carbon-free combustion make it a viable alternative to fossil fuels and hydrogen. The engine design also leverages existing hydrogen internal combustion engine (ICE) platforms, enabling cost-effective retrofits. Dr. Cheolwoong Park of KIMM says the result is “a groundbreaking improvement over conventional ammonia engines.” At the same time, Hyundai/Kia’s Dr. Seungwoo Lee emphasized its role in overcoming hydrogen transportation barriers.
Ammonia joins the renewable family
As researchers refine larger-scale engine models, explore long-term durability, and expand infrastructure for green ammonia production, the technology could power everything from cars and ships to industrial generators without emitting carbon. This marks a promising milestone toward a future where ammonia joins hydrogen and other renewables as a cornerstone of sustainable, zero-emission power systems.
