A Comprehensive Life Cycle Assessment of an LNG Carrier from Cradle to Grave

Abstract This research paper presents a comprehensive Lifecycle Assessment (LCA) of a 174,000 m3 LNG Carrier, covering the entire lifecycle from material extraction to ship breaking and material recycling and disposal (cradle to grave). Adhering to ISO 14040 and 14044 standards, the study employed SimaPro software for modelling and utilized CML - IA methodology for impact assessment, including categories such as global warming and human toxicity. Monte Carlo simulations were conducted for uncertainty analysis, enhancing the study's reliability. The assessment comprised three phases: Cradle-to-Gate (ship building), Gate-to-End of Operations (ship operations), and End of Operations to Grave (ship decommissioning and recycling). Data from shipyards and operators ensured industry- specific relevance. The Cradle-to-Gate stage evaluated the environmental impacts of shipyard processes, raw materials, and equipment, establishing a baseline for scope 3 emissions estimation. The LCA establishes a comprehensive scope 3 assessments offering insights beyond direct operational activities, fostering collaboration with suppliers for shared environmental goals. By assessing the Global Warming Potential (GWP) of materials, the study highlighted the ecological benefits of adopting sustainable options like 'green steel.' It also examined the impact of renewable energy use in the yard. The Gate-to-End of Operations stage analyzed operational impacts, considering different ship modes, maintenance, and emissions associated with fuel use. The study emphasized the importance of considering both Well-to-Tank and Tank-to- Wake emissions in LCA for informed decisions on fuel selection based on sustainability goals. Quantifying environmental impacts throughout the LNG Carrier's lifecycle provides valuable information for decisionmakers, shipbuilders, and regulators. The research offers strategic guidance for stakeholders to align with sustainability goals, enabling continuous monitoring and evaluation. This approach empowers decision-makers to implement targeted improvements, steering the maritime industry towards a more environmentally responsible and sustainable future. The total Global Warming Potential for the LNG carrier was found to be 2370 million kg CO2 eq. The assessment identified the Gate to End of Operations phase, particularly Ship Operations, as the primary contributor to the LNG carrier's Global Warming Potential (GWP), primarily due to fuel use. The End of Operations to Grave phase, focusing on ship recycling, highlighted steel melting as a significant contributor to GWP, underscoring the need for sustainable ship-breaking practices.