FOUR-STROKE ENGINES
UK AMMONIA ENGINE STUDY EYES RCS ENGINE CONCEPT An ambitious research project has been launched by the UK to develop ‘disruptive’ engine technology based on the use of ammonia fuel. The initiative gives new momentum to the drive towards a decarbonised marine sector, writes David Tinsley
8 A multi-cylinder prototype based on N2 Power’s Recuperated Split Cycle engine technology is under development
Ultra-low NOx combustion systems will be explored by the 20-strong, UK cross-industry R&D consortium over a five-year period, funded by the Engineering and Physical Sciences Research Council (EPSRC). Entitled Decarbonised Clean Marine: Green Ammonia Thermal Propulsion (MariNH3), the £5.5m (US$7.2m) endeavour got under way at the beginning of this month (March) under the leadership of the University of Nottingham. MariNH3 will be conducted by a multi-disciplinary consortium to address the challenges associated with green ammonia, i.e. ammonia produced from renewable sources, for marine applications. Ammonia is regarded as offering the potential to play a significant role as a sustainable future fuel in both advanced and retrofitted engines. When burned, ammonia turns back into nitrogen and water and does not yield the CO2 that results from fossil fuel combustion. However, the relationship between the fuel’s slow-burning properties and NOx formation needs to be addressed. The MariNH3 programme, extending to 28 February 2027, seeks to overcome the various technical and economic unknowns and challenges by exploring disruptive NH3 engine concepts capable of high thermal efficiency and ultra-low NOx. The remit of the research partners also embraces consideration of type approval and legislation issues, including risk assessment to support international rule development.
The scope of possible solutions and technologies for retrofitting is deemed to be of central importance given the ‘net zero’ timescales set by legislators and other bodies in relation to the scale of the world merchant fleet and service life longevity of large vessels and marine machinery. An estimated 80% of the sector’s greenhouse gas emissions emanate from deep-sea traders such as bulk carriers, tankers and container ships. Alongside the University of Nottingham, the partners in MariNH3 include the BMT Group, Lloyd’s Register, RollsRoyce, Cummins Power Generation, Johnson Matthey, the Ricardo Group, MAHLE Powertrain, Dolphin-N2, and the Maritime & Coastguard Agency (MCA), plus energy heavyweights BP and Shell. Salient to MariNH3 objectives, MAHLE’s proprietary Jet Ignition technology is a fast burning combustion system, while Dolphin-N2’s Recuperated Split Cycle (RSC) technology offers possibilities in achieving diesel-like efficiency but with exceptionally low NOx. A single-cylinder proof of concept RSC engine has been running at Brighton University, and the first multi-cylinder prototype is in development. The fact that the internal combustion engine is the platform for MariNH3 research in the bid to decarbonise commercial shipping reflects the shortcomings of battery electric power as regards practical range, payload and total cost. Electric propulsion, though, is predicted to become the dominant mode in future local and light duty marine transport.
For the latest news and analysis go to www.motorship.com/news101
MARCH 2022 | 15
