Advancements and Challenges of Ammonia as a Sustainable Fuel for the Maritime Industry

Abstract

The maritime industry needs sustainable, low-emission fuels to reduce the environmental impact. Ammonia is one of the most promising alternative fuels because it can be produced from renewable energy, such as wind and solar. Furthermore, ammonia combustion does not emit carbon. This review article covers the advantages and disadvantages of using ammonia as a sustainable marine fuel. We start by discussing the regulations and environmental concerns of the shipping sector, which is responsible for around 2% to 3% of global energy-related CO2 emissions. These emissions may increase as the maritime industry grows at a compound annual growth rate of 4.33%. Next, we analyze the use of ammonia as a fuel in detail, which presents several challenges. These challenges include the high price of ammonia compared to other fossil fuels, the low reactivity and high toxicity of ammonia, NOx, and N2O emissions resulting from incomplete combustion, an inefficient process, and NH3 slipping. However, we emphasize how to overcome these challenges. We discuss techniques to reduce NOx and N2O emissions, co-combustion to improve reactivity, waste heat recovery strategies, the regulatory framework, and safety conditions. Finally, we address the market trends and challenges of using ammonia as a sustainable marine fuel.