(179a) Promising Marine Alternative Fuel Pathways with Consideration of Well to Wake Emissions and Costs

Recognizing that marine fuel substitution is a long-term process, the research emphasizes the urgent need for consensus and action within the maritime community to accelerate the transition towards clean shipping. This aligns with broader sustainability trends, including the increasing investor demand for quantifiable environmental impact and the drive for robust ESG data highlighted in industry outlooks.

This work investigates the potential of alternative marine fuels to decarbonize the shipping industry and meet the IMO's 2050 emissions reduction targets. The study conducts a comprehensive technological review of promising alternative fuels. Key fuel properties, feedstocks, production processes, transportation/storage logistics, and end-use applications are analyzed for zero-carbon and carbon-neutral options. As the well-to-wake (WtW) emission factors are in the developing stage, it is well accepted that dynamic emission factors other than fixed values will be the solution for WtW emission factor database since their values will vary as technology improves in different regions. This study applies a regional based life cycle assessment to evaluate the current and outlook of promising marine fuel pathways. A novel index, GHG Abatement Cost (GAC), is developed to demonstrate the cost-effective fuel routes for achieving the mid-term/long-term IMO decarbonization goals. This index statistically assesses the trade-offs between fuel cost and GHG emission savings, specifically focusing on the WtW process. In the WtW emission cost-effectiveness analysis, this study has formulated three hypotheses (e-fuels/bio-fuels/blue fuels high uptake scenarios) to identify the most economical means of achieving the 2050 objectives. Based on the three developed scenarios, the cost-effectiveness performance for 2040 and 2050 fuel pathways can be calculated accordingly and the results for the identified fuel pathways to showcase the decarbonization outlook along IMO strategy on reduction of GHG emissions from ships.