A review on green ammonia as a potential CO₂ free fuel

A very promising alternative fuel that can take the place of present fossil fuels is ammonia. Given that it is a hydrogen carrier with no carbon-based emissions and can be manufactured using renewable sources, it is a green fuel for Internal Compression Engine (ICE) with promising future applications. The notion of using pure ammonia in fueling combustion engines is not new, but despite numerous studies that looked into the possibility, Combustion engine fueling techniques based on ammonia are not yet ready for commercialization. This is because using this toxic molecule still presents significant challenges due to its supply, safety concerns, and physical differences from conventional fossil fuels. The objective of this review is to provide readers with a broad overview of the green ammonia research as a potential replacement fuel for ICE, as well as a look at potential future uses and workable solutions to related issues. The physicochemical characteristics of ammonia are discussed to determine the key benefits and drawbacks of its application in combustion engines, with an emphasis on the difficulties, advantages, and potentials for the future as well as recent technological advancements to get around the obstacles related to its production, storage, and utilization. Additionally, this work delves into sustainable approaches for the production of green ammonia and its application in spark ignition (SI) and compression ignition (CI) engines. Within this context, this study elucidates the foundational principles, research findings, practical considerations, economic implications, and prospective outlook towards a paradigm shift wherein ammonia assumes a significant role as a primary energy source in combustion engines. More study of ammonia combustion phenomena is necessary to propose solutions to these problems. This overview clarifies recent developments in ammonia technology from the point of manufacture to the point of consumption.