The long-distance transport sector will not be easily electrified. Aviation will primarily use sustainable aviation fuels (SAF) to meet its decarbonization targets. Although marine will also be hard to decarbonize this sector has several lower carbon-intensive (CI) fuel options such as electric-hybrids, liquefied natural gas (LNG), 'green' methanol, ammonia, hydrogen, and biobased fuels. The advantages of using these latter fuels are their ready integration into much of the existing infrastructure, their availability, their use in today's marine engines, substantial carbon emission reductions, and established supply chains. However, there will be increasing competition for the oleochemical/lipid feedstocks from the trucking and aviation sector, while the cost, availability, and overall sustainability of these biofuels are problematic. In the longer term, it is hoped that biomass-derived biocrudes produced via thermochemical processes such as pyrolysis, hydrothermal liquefaction (HTL) and gasification will supplement the lipid feedstocks and be more sustainable, cheaper, and plentiful. The robustness of marine engines is also conducive to the direct use of straight vegetable oils (SVO) and biocrudes. However, 'enabling' policies such as the British Columbia low carbon fuels standard will be required to bridge the initial price gap between fossil and low- CI fuels while the international nature of most marine traffic will require agreement on how the life cycle analysis (LCA) is determined. (c) 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.
