The Potential Role of Ammonia as Marine Fuel—Based on Energy Systems Modeling and Multi-Criteria Decision Analysis

Abstract

To reduce the climate impact of shipping, the introduction of alternative fuels is required. There is a range of different marine fuel options but ammonia, a potential zero carbon fuel, has recently received a lot of attention. The purpose of this paper is to assess the prospects for ammonia as a future fuel for the shipping sector in relation to other marine fuels. The assessment is based on a synthesis of knowledge in combination with: (i) energy systems modeling including the cost-effectiveness of ammonia as marine fuel in relation to other fuels for reaching global climate targets; and (ii) a multi-criteria decision analysis (MCDA) approach ranking marine fuel options while considering estimated fuel performance and the importance of criteria based on maritime stakeholder preferences. In the long-term and to reach global GHG reduction, the energy systems modeled indicate that the use of hydrogen represents a more cost-effective marine fuel option than ammonia. However, in the MCDA covering more aspects, we find that ammonia may be almost as interesting for shipping related stakeholders as hydrogen and various biomass-based fuels. Ammonia may to some extent be an interesting future marine fuel option, but many issues remain to be solved before large-scale introduction.

Power-to-X in Denmark: An Analysis of Strengths, Weaknesses, Opportunities and Threats

“…Schmidt et al [66] have reviewed power-to-liquids and their role in the aviation sector, pointing out that P2X is a viable option for the transformation of the aviation sector. According to the experts, a potential end-use sector is the shipping sector with ammonia, which has been investigated in the literature [67] and also specifically for the Danish case [68]. Another possible application is in the chemical industry to displace fossil-based products.…”

Decarbonization in Shipping Industry: A Review of Research, Technology Development, and Innovation Proposals

“…However, producing green ammonia is not yet cost-competitive compared to conventional ammonia, where "90% of its production relies on fossil fuels such as natural gas" [8]. There are several global initiatives to produce green ammonia, such as the ammonia producer Yara (one of the world's leading ammonia producers) is planning to build a demonstration plant for the next-generation green ammonia synthesis plant that will utilize solar energy by 2025 [57,58].…”

“…Wärtsilä has already performed some initial tests of ammonia in dual-fuel and spark-ignited gas engines, which "will be followed by field tests in collaboration with ship owners from 2022, and potentially also with energy customers in the future" [110]. There are additional initiatives from MAN Energy solutions who "claim that their dual-fuel engine developed for LPG may use liquid ammonia in a dual-fuel setup" [57,111]. In addition, "MAN Energy Solutions, Shanghai Merchant Ship Design and Research Institute (SDARI) and American Bureau of Shipping (ABS) have a development project for an ammonia-fueled feeder container vessel intended to use this technology" [57].…”

“…There are additional initiatives from MAN Energy solutions who "claim that their dual-fuel engine developed for LPG may use liquid ammonia in a dual-fuel setup" [57,111]. In addition, "MAN Energy Solutions, Shanghai Merchant Ship Design and Research Institute (SDARI) and American Bureau of Shipping (ABS) have a development project for an ammonia-fueled feeder container vessel intended to use this technology" [57].…”

Criteria and Decision Support for A Sustainable Choice of Alternative Marine Fuels

“…Gases introduce other technical challenges, where the technology is quite well developed for natural gas/LNG, and a conversion of a traditional diesel system can be done, although at a high cost. For ammonia, the technology readiness level is very low [42]. Anhydrous ammonia is a gas that requires high pressure/low temperature storage like LNG, although not at such a low temperature.…”