KEY ISSUES IN LCA METHODOLOGY FOR MARINE FUELS

The results of these four case studies highlight the most critical assumptions and the importance of understanding the reason for the life-cycle carbon accounting of fuels. [...] The goal defines the research question that the LCA is intended to answer and therefore determines the LCA methods used to assess the impacts of the product system studied. [...] The final use of co-products is outside the system, as are the upstream emissions attributable to the energy and chemicals used to produce the system’s inputs. [...] In Figure 9, below, the feedstocks are on the left side and the renewable feedstocks are in green and the fossil-fuel-based feedstocks are in gray. [...] The next three bars display the impact of expanding the analysis to upstream production emissions (teal), the range of impacts of different allocation methods (orange), and the decision to include ILUC emissions (brown).