A review of recent studies and emerging trends in plasma-assisted combustion of ammonia as an effective hydrogen carrier

Recently, ammonia is getting more attractive as a potential alternative fuel for future power generation and transportation purposes due to its ability to reduce consumption of fossil fuels, soot, CO2 emissions, and hydrocarbon pollutants. In the recent past, several studies aimed to the development of ammonia combustion systems have been conducted. However, ammonia combustion systems face several challenges, such as poor ignition timings, lower burning velocity, low energy density, shorter flammability limits than hydrocarbons. These issues are compounded by the significant increase in NOx emissions, which makes practical application of ammonia challenging. Various conventional methods, such as blending ammonia with other hydrocarbons and hydrogen, have been employed to improve combustion performance and reduce NOx emission. Meanwhile, it increased the engine complexities and at the same time, it raised CO2 and NOx emissions. Recently, plasma-assisted combustion (PAC) has emerged as a promising technology to boost the ammonia combustion process by improving ignition delay timings, increasing flame speed, extending flammability limits, and reducing NOx emissions. In recent years, plasma-assisted combustion (PAC) has emerged as a promising technology to enhance the ammonia combustion process by improving ignition delay timings, increasing flame speed, extending flammability limits, and reducing NOx emissions. Nevertheless, only a few studies on plasma-assisted ammonia combustion (PAAC) are available in the literature. This review paper aims to summarize the latest advancements in the field of PAAC during the last years, including progress in the development of numerical models and experimental studies. The paper highlights the detailed procedure of PAAC numerical modeling and the limitations of numerical models. Finally, the latest numerical and experimental developments of PAAC have been discussed.