The aviation sector currently accounts for 2-3% of global Greenhouse Gas (GHG) emissions, while the projected increased air travel demand (average 3.4% per year), might surge the aviation fuel use. This increase in jet fuel demand, associated with the current decarbonization pathway of other sectors might increase the aviation’s absolute emissions, as well as its relative global GHG share. This scenario has driven the aviation stakeholders into a decarbonization strategy, focused on an immediate and gradual GHG reduction effort associated with a net-zero commitment by 2050.
Meanwhile, the aviation sector is known as one that set most difficulties to use alternative fuels and/or powertrains, such as battery electric or sustainable hydrogen fueled propulsion systems, already used on some road and rail applications, but still restricted to the aviation, due to the inherent weight and volume tight requirements. In this context, the sustainable aviation fuels (SAF) are set as the most promising short and medium term aviation decarbonization tool, due to their drop-in feature, which ultimately allows its use on the current aircraft fleet, as well as the fuel storage and distribution systems, provided the certified blends.
The prominent SAF role brings increasing demand volumes in the foreseeable future. However, the SAF scaling process from the current 0.1% share of the global jet fuel market faces an array of challenges (technical, regulatory – including the sustainability associated with the feedstocks and the production pathways and economic), requiring collective efforts to boost the technology deployment, address demand reliability and set an efficient regulatory frameworks. Different regulatory approaches have been proposed, with the so called mandates, adopted, for instance, in the European Union and to be adopted in Brazil (from 2027), to encourage investments for SAF production, while the United States (U.S.), the larger jet fuel market in the world, has adopted the use of incentives, to foster the SAF production capacity.
This work presents, in a review format, a chronological timeline of the challenges associated with the implementation and scale use of SAF. It highlights the technical, regulatory and economic topics associated with the aviation’s net zero commitment, as well as sets the required roles of the associated stakeholders to make SAF a feasible alternative.