Sustainable transport by use of alternative marine and aviation fuels—A well-to-tank analysis to assess interactions with Singapore's energy system

Sustainable economic development and renewable energy carriers are challenges facing hub cities that will influence their future role in trade and transport. The objective of this paper is to discuss the interactions between alternative transport fuels for international applications and Singapore's energy system as a central hub of global transport. The process chains for the supply of conventional fuels, liquefied natural gas, biofuels, and liquid hydrogen in Singapore are analysed by applying a well-to-tank analysis, following which the energy demand and the associated greenhouse gas emissions are calculated. A sensitivity analysis is performed to assess the individual impacts of various processes. A comparison of process chains for the supply of fuels for marine and aviation purposes shows that conventional energy carriers and liquefied natural gas achieve higher energy efficiencies than biofuels and liquid hydrogen. Alternative fuels reduce greenhouse gas emissions by varying degrees depending on the fuel type. An analysis of interactions with Singapore's energy system identifies emerging opportunities and challenges for the city-state's economic system associated with future development of international transport. Although alternative fuels offer the possibility of diversifying Singapore's energy supply, creating new business opportunities, and increasing Singapore's impact on fighting climate change, limited resource potentials and higher energy prices set new challenges to secure Singapore's role as an international trade and transport hub.