NUS launches IRGR project to develop near-zero-emissions ammonia marine engines

The National University of Singapore (NUS) has launched a new research initiative aimed at advancing next-generation ammonia-fuelled marine engines, as part of efforts to reduce greenhouse gas emissions from global shipping.

The project, officially launched on 4 February 2026, will be based at the College of Design and Engineering (CDE) and led by the NUS Centre for Hydrogen Innovations (CHI). It is supported by funding from the Singapore Maritime Institute (SMI) and involves collaboration with academic and industry partners in Singapore and overseas.

At the core of the programme is the development of an in-cylinder reforming gas recirculation (IRGR) engine concept. The research team says the design seeks to address current limitations in ammonia-fuelled engines, particularly in areas such as combustion efficiency, thermal stability and pollutant emissions.

“Ammonia has been recognised as one of the most promising fuels for achieving near-zero greenhouse gas emissions in marine transportation, but current ammonia engines face significant challenges in efficiency and emissions,” said Associate Professor Yang Wenming from the Department of Mechanical Engineering at NUS, who serves as Principal Investigator. “The IRGR concept is designed to address these limitations by improving combustion efficiency while sharply reducing unburned ammonia and other pollutants.”

A dedicated laboratory has been established on the CDE campus to support the project, including an engine test room, control room and facilities for combustion and systems research. According to NUS, the initiative also aims to strengthen Singapore’s role in maritime innovation by anchoring advanced engine research within a broader ecosystem of industry collaboration.

Professor Silvija Gradecak, Vice Dean (Research and Technology) at CDE, said:

“Marine transportation is central to global trade, yet it remains one of the most challenging sectors to decarbonise. Through this project, the team aims to develop and demonstrate the world’s first prototype engine based on the IRGR concept, paving the way for the practical adoption of ammonia as a marine fuel.”

Shipping is estimated to account for around 3% of global carbon emissions and faces increasing regulatory pressure to align with the International Maritime Organization’s 2050 net-zero target. While ammonia produces no carbon dioxide at the point of combustion and is considered easier to store and transport than hydrogen, technical barriers remain to its commercial deployment.

International collaboration forms a key component of the project. Professor Li Tie of Shanghai Jiao Tong University, a partner institution, said:

“The International Maritime Organization’s net-zero emissions target must be achieved by 2050, and the time left is very short. This goal cannot be realised by any single institution or country. It requires disruptive technologies and strong international cooperation, and the IRGR project reflects exactly that kind of collaboration.”

The consortium includes Nanyang Technological University, A*STAR National Metrology Centre and Keppel Energy Nexus, alongside industry partners Daihatsu and American Bureau of Shipping. The partners are expected to contribute expertise in engine development, safety standards, certification pathways and commercialisation.

The launch event included the signing of research collaboration agreements between NUS and Daihatsu, and between NUS and ABS.

Professor Lee Poh Seng, Head of the Department of Mechanical Engineering at NUS, said:

“This project is not merely the start of another research programme, but a deliberate step into one of the hardest and most consequential engineering challenges in the energy transition. Decarbonising hard-to-abate sectors like shipping requires technologies that can be validated, scaled and trusted in real-world operations.” The project is scheduled to run for three years, with the research team working towards scalable engine concepts that could support the deployment of low- and zero-emissions vessels.