Environmental impact assessment of green ammonia-powered very large tanker ship for decarbonized future shipping operations

Maritime transport has been critical for the world economy and trade for centuries. Greenhouse gases and their environmental impacts are significant contributors to global warming and climate change and have compelled authorities to take substantial steps toward decarbonizing the energy system. Since then, the International Maritime Organization, policymakers, classification societies, shipping companies, and related stakeholders have been increasingly concerned about the environmental impacts of carbon-based fuels. Green ammonia as an energy vector is considered one of the top contenders for future energy systems. However, gaps remain in the literature regarding environmental impact assessment and usage. This study assessed the environmental impacts and performance of a newly built green ammonia-powered, very large oil and chemical tanker designed for the Atlantic Ocean route from Rotterdam to New York Port. This life cycle assessment study considers a tanker's entire transport life cycle from its manufacturing process to the production, material transportation, energy required for manufacturing, operation, maintenance, disassembly, scrap processing, and using green ammonia as a marine fuel. Performed an environmental impact assessment using IPCC, Environmental footprint, and ReCiPe midpoint Hierarchist (H) methodologies for five broad impact groups: Eutrophication, ozone, Climate change, Human and Ecotoxicity, and analyzed green ammonia process impacts. This study performed a comparative environmental performance assessment of HFO, LNG, blue ammonia, and green ammonia using impact categories such as GWP 100 and GTP 100. Green ammonia exhibited the most substantial negative percentage difference values (higher than -90%) per tonne-kilometer, indicating a lower environmental impact than all fuels in both categories. Adequately managing the ammonia-powered marine energy system would be indispensable for reducing environmental footprints and successfully lowering carbon, nitrogen oxide, and ammoniabased emissions.

Automated summary

This study assessed the environmental impacts and performance of a newly built green ammonia-powered tanker, and found that green ammonia has lower environmental impact compared to other fuels. Adequately managing the ammonia-powered marine energy system is crucial for reducing environmental footprints and lowering carbon, nitrogen oxide, and ammonia-based emissions.