The Dawn of a New Era in Sustainable Maritime Engineering at NUS
The National University of Singapore (NUS), a leading institution in higher education and research in Singapore, has officially launched a transformative project aimed at developing near-zero-emissions ammonia marine engines. Announced on February 4, 2026, this initiative underscores NUS's commitment to tackling one of the most pressing challenges in global sustainability: decarbonizing the maritime sector. As Singapore solidifies its position as a global maritime hub, NUS's efforts align perfectly with national goals to pioneer green technologies in shipping.
Maritime transportation powers over 90% of global trade, yet it contributes approximately 3% of worldwide greenhouse gas (GHG) emissions. With the International Maritime Organization (IMO) mandating net-zero emissions by 2050, including interim targets of 20-30% reduction by 2030 and 70-80% by 2040, innovative solutions like ammonia-fueled engines are critical. This project, housed within the NUS College of Design and Engineering (CDE), promises to bridge the gap between research and real-world application.
🚢 Decoding the In-Cylinder Reforming Gas Recirculation (IRGR) Technology
At the heart of the project lies the In-Cylinder Reforming Gas Recirculation (IRGR) engine concept, a novel approach designed to overcome the inherent limitations of ammonia combustion in marine engines. Ammonia (NH3), a carbon-free fuel, decomposes into nitrogen and hydrogen during combustion, producing no CO2 at the point of use. However, its low flame speed, high ignition energy requirements, and tendency to produce nitrogen oxides (NOx) and unburned ammonia slip have hindered adoption.
The IRGR process works in a step-by-step manner within a multi-cylinder engine setup:
- Dedicated Reforming Cylinder: One or more cylinders operate at high temperatures to catalytically reform ammonia into hydrogen-rich syngas (primarily H2 and N2).
- Gas Recirculation: This reformed gas is cooled and recirculated back into the intake of the main combustion cylinders.
- Enhanced Combustion: The hydrogen boosts flame speed and stability in the main cylinders, allowing efficient ammonia burning with pilot diesel ignition for reliability.
- Emission Control: Resulting in sharply reduced unburned NH3, NOx, nitrous oxide (N2O), and overall GHG emissions, while improving thermal efficiency by up to 15.8% based on preliminary studies.
Prior research by NUS's Associate Professor Yang Wenming and Dr. Zhou Xinyi, published in prestigious journals like Joule and Nature Communications, laid the groundwork, demonstrating IRGR's potential through simulations and bench tests.
Ammonia as the Future Fuel: Advantages and Singapore's Strategic Position
Ammonia stands out among alternative marine fuels due to its high energy density, ease of liquefaction at moderate pressures, and existing global production infrastructure—over 180 million tons annually, much for fertilizers. Unlike hydrogen, it avoids cryogenic storage challenges. Singapore, the world's second-busiest port and top bunkering hub, has already conducted the first ammonia bunkering trials in 2024 and is scaling up under the Maritime Singapore Decarbonisation Blueprint.
Projections indicate the marine low-carbon ammonia propulsion market will grow from USD 4.6 billion in 2026 to USD 12.8 billion by 2036, driven by engine makers like MAN Energy Solutions and WinGD entering commercial service this year. Yet, challenges persist: toxicity requires stringent safety protocols, and supply chains need greening via renewable ammonia production.
NUS Centre for Hydrogen Innovations: A Hub of Expertise
The project is spearheaded by the NUS Centre for Hydrogen Innovations (CHI), established to advance hydrogen and ammonia technologies. Principal Investigator Associate Professor Yang Wenming, from the Department of Mechanical Engineering, brings years of expertise in advanced combustion systems. Supported by Senior Research Fellow Dr. Zhou Xinyi, the team builds on CHI's portfolio, including ammonia cracking for gas turbines and hydrogen membranes.
NUS CDE's state-of-the-art facilities, including the new dedicated IRGR lab with engine test rooms and control centers, will enable rapid prototyping. This aligns with Singapore's higher education focus on interdisciplinary research, fostering PhD students and postdocs in mechanical engineering and sustainable energy.
"This project is not merely research; it's a step into consequential engineering challenges," notes Professor Lee Poh Seng, Head of Mechanical Engineering.
Powerful Industry-Academia Partnerships Driving Innovation
Collaboration is key: Academic partners include Shanghai Jiao Tong University, Nanyang Technological University (NTU), and A*STAR's National Metrology Centre. Industry heavyweights Keppel Energy Nexus (Singapore's energy transition leader), Daihatsu (global marine engine pioneer), and the American Bureau of Shipping (ABS) for certification ensure commercial viability.
Funded by the Singapore Maritime Institute (SMI), the three-year initiative emphasizes practical validation, safety standards, and scalability. Professor Silvija Gradecak, CDE Vice Dean (Research), highlights: "We're paving the way for ammonia's practical adoption in low- and zero-emission vessels."
Read the full NUS announcementAddressing Key Challenges: From Efficiency to Emissions
Current ammonia engines suffer 20-30% lower efficiency than diesel equivalents and elevated NOx/N2O due to high combustion temperatures. IRGR mitigates this by diluting mixtures with recirculated gas, lowering peak temperatures while hydrogen accelerates burn rates.
- Efficiency Gains: Projected 10-16% improvement in brake thermal efficiency.
- Emission Reductions: Unburned NH3 slip <10 ppm, NOx <0.4 g/kWh, N2O minimized.
- Safety Enhancements: Reduced toxicity risks via optimized combustion.
- Cost Benefits: Single-fuel ammonia supply simplifies logistics over dual-fuel systems.
Real-world validation will occur in the prototype phase, targeting certification-ready designs by 2029.
Singapore's Maritime Green Revolution and NUS's Pivotal Role
As a maritime nation, Singapore invests heavily in decarbonization, with MPA leading ammonia supply chain development. NUS's project complements initiatives like the world's first ammonia-powered vessel bunkering in its port. By 2030, Singapore aims for multi-fuel bunkering readiness, positioning graduates for high-demand roles in green maritime tech.
For aspiring engineers, this opens doors in research jobs and faculty positions focused on sustainable energy. Explore academic career advice to prepare.
Global Implications and Future Outlook
The IRGR prototype could accelerate ammonia adoption, supporting IMO goals amid rising demand—over 30 ammonia engines ordered globally for 2026 delivery. For higher education, it exemplifies how Singapore universities drive D+I (Discovery and Innovation), training talent for net-zero transitions.
Stakeholder perspectives vary: Industry seeks scalable tech, governments push regulations, while academics emphasize international cooperation, as Professor Li Tie notes: "Net-zero requires disruptive tech and global teamwork."
Photo by Aditya Hegde on Unsplash
Career Opportunities in Green Maritime Research at Singapore Universities
This project highlights booming opportunities in Singapore's higher education for mechanical engineers, hydrogen specialists, and sustainability experts. NUS and NTU are hubs for such roles, with demand for postdocs, research assistants, and lecturers surging.
- Key skills: Combustion modeling, engine testing, emission analysis.
- Salary insights: Professor roles average SGD 150k+, research fellows SGD 80k+.
- Actionable advice: Build portfolios with simulations; network via PIER71.
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Conclusion: Charting the Course to Net-Zero Shipping
NUS's IRGR project marks a milestone in higher education-led innovation, blending academia, industry, and policy for sustainable shipping. As ammonia engines scale, expect profound impacts on global trade and climate goals. Stay informed and engaged—visit Rate My Professor, explore higher ed jobs, career advice, or university jobs. Post a vacancy at AcademicJobs.com to attract top talent.