Cradle-to-gate life cycle assessment of ships: A case study of Panamax bulk carrier

Seaborne transport plays an important role in global transportation, and ships' emissions are worth considering. By applying life cycle assessment method, the environmental impacts of ships could be evaluated. Life cycle assessment is an effective tool as this method provides a holistic perspective of a product or a service in its life cycle. In an attempt to clarify emissions released from the cradle-to-gate life cycle of ships, especially from processes in shipbuilding which were not considered adequately from some previous studies, this study conducts life cycle assessment method to assess the environmental impacts of a Panamax bulk carrier from raw material extraction to shipbuilding phase. In order to clarify life cycle emissions, some helpful mathematical formulas are also established. Ten environmental categories of CML 2001 life cycle impact assessment methodology that are relevant to the marine context are chosen for evaluating the environmental impacts. To obtain emission inventory and impact assessment results, a life cycle assessment software-GaBi-has been used. The results show that material extraction and production phase accounts for more than 85% carbon dioxide, carbon monoxide, nitrous oxide, and methane, while shipbuilding phase is responsible for 99.91% volatile organic compounds, 36.08% non-methane organic compounds, and 26.76% particulate matter emissions. In relation to environmental indicators, material consumption is much more significant than other processes and accounts for more than 86% of values of 10 environmental categories. This study is useful as it provides necessary information for life cycle assessment in the shipping industry in the future.