Development of sustainable low-NOx and high efficiency Ammonia marine engine

forthcoming

Ammonia (NH3) has gained popularity in recent years as a potential carbon-free fuel, particularly for nautical applications. However, there are clear difficulties in using ammonia as a fuel directly in diesel engine applications due to high auto-ignition temperature, unstable flames and inefficient burning. This issue could be effectively solved by co-firing ammonia with more reactive fuels to improve combustion features. As a result, NH3/H2 co-firing has significant advantages and a wide range of potential in carbon-neutral and low-emission combustion as compared to the traditional co-firing technique with natural gas and diesel. Moreover, the combustion of NH3/H2 produced high NOx and unburnt NH3 which is beyond the acceptable limit. NOx emissions (NO, N2O and NO2) majorly contribute to air pollution. They cause many adverse effects on environment including respiratory tract diseases on human health. Therefore, it is important to overcome NOx and slip- NH3 issues in NH3 combustion engines. To reduce NOx and unburnt NH3 from NH3 combustion marine engines, it is important to understand the formation of NOx through the elementary combustion reaction at the micro-level with advanced lean combustion technology. Therefore, in this proposed research, the two advanced combustion concepts of Turbulent Jet -Reactivity Controlled Compound Ignition (TJ-RCCI) and In-cylinder Reforming Gas Recirculation (IRGR) are projected for the successful reduction of NOx and slip- NH3 in NH3 marine engines with the improvement of thermal efficiency. It assumes that merging TJ-RCCI & IRGR technology should have the following advantages: (1) better combustion efficiency than neat NH3, (2) lower NOx emission, (3) saving fuel energy due to the heat transfer loss of the external reformer, (4) reduce the high cost of catalyst and increases their life period and (5) lower marine GHG emissions.