A Review of the Latest Trends in the Use of Green Ammonia as an Energy Carrier in Maritime Industry

Abstract

This review paper examines the key barriers to using green ammonia as an alternative fuel in maritime industry. A literature survey is performed based on research articles and grey literature, with the aim of discussing the technoeconomic problems with and benefits of ammonia and the relevant technologies. The limitations of ammonia as a maritime fuel and its supply chain, the expected percentage demand by 2030 and 2050, its economic performance compared to other shipping fuels such as hydrogen, and the current regulations that may impact ammonia as a maritime fuel are discussed. There are several key barriers to ammonia’s wide adoption: (1) High production costs, due to the high capital costs associated with ammonia’s supply chain; (2) availability, specifically the limited geographical locations available for ammonia bunkering; (3) the challenge of ramping up current ammonia production; and (4) the development of ammonia-specific regulations addressing issues such as toxicity, safety, and storage. The general challenges involved with blue ammonia are the large energy penalty and associated operational costs, and a lack of technical expertise on its use. Regardless of the origin, for ammonia to be truly zero-carbon its whole lifecycle must be considered—a key challenge that will aid in the debate about whether ammonia holds promise as a zero-carbon maritime fuel.

Awareness increases acceptance and willingness to pay for low-carbon fuels amongst marine passengers

“…Therefore, it does not emit CO 2 or SO x during combustion [47] . However, although several studies focus on the bottlenecks of ammonia supply and production [48] , the major drawback of using ammonia is the nonexistence of engines capable of running on it. Even though extensive research, currently, only dual ammonia-diesel engines exist [49] .…”

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“…An opportunity exists to retrofit LNG ships with ammonia [49]. Estimates show that ammonia could represent by between 20% and 99% of the total projected fuel mix of the shipping industry by 2050 [46,50,51].…”

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