Decarbonisation Technology - February 2024 Issue

requires e-SAF to increase from 1.2% of aviation fuels in 2030 to 35% in 2050. European regulations promote advanced biofuels sourced from feedstocks that are not in direct or indirect competition with food resources. These include recycled carbon fuels (potentially using waste from non-renewable sources) and low-carbon fuels (possibly including hydrogen produced from nuclear power). These options all share the goal of achieving at least a 70% reduction in greenhouse gas emissions. In addition to these two major regulatory frameworks, several other countries (such as China, India, and Thailand) are currently preparing their SAF regulations. These will be released shortly so the industry can prepare for the first milestones. Expanding the global supply of SAF To align with all regulations, the aviation industry must significantly ramp up its adoption of SAF in the coming years. The industry will have to expand the range and increase the production of available feedstock for this to be possible. Today, most of the world’s SAF comes from vegetable oils such as rapeseed and palm oil. Some regulations, such as the revised European Renewable Energy Directive, ban the use of soy and palm oils for biofuels because the feedstock is in competition with the food industry (EUR- Lex, 2023). As a result, lipidic second-generation feedstocks, including animal fats, used cooking oil, and palm oil mill effluent, are taking over. These feedstocks will only allow the industry to meet the first milestone with few percent of SAF incorporation. To move beyond this plateau caused by the limited volume of lipidic second- generation feedstock, the second phase will require constructing industrial plants to produce SAF from other feedstocks. Three major feedstocks for the future of SAF In collaboration with its partners, Axens has already developed expertise to utilise the next generation of feedstocks for the production of SAF and e-SAF. These include biomass, which are typically residues from agriculture, forestry, and other waste products that do not compete with food crops. CO₂ captured from sources such as flue gas, cement or steel factories and power plants or biogenic CO 2 (produced from

What is SAF?

Carbon Intensity (CI) score. The CI score then determines the sustainability of a given fuel compared to fossil fuel baselines. Additionally, it provides a foundation for regulatory and credit structures to incentivise CI reductions throughout the entire SAF value chain. A different approach is taken in Europe, where the European Union has committed to reducing its overall emissions by 55% by 2030. To reach this goal, the European Commission introduced its ‘Fit for 55’ package of legislative proposals. Among them, 11 initiatives have a direct impact on transport, and ‘ReFuelEU’ is the initiative dedicated to aviation. Under this initiative, the SAF requirement will rise from 2% of aviation fuels in 2025 to 6% by 2030 and then 70% in 2050. A sub-obligation of this SAF mandate kerosene. It can currently be blended up to 50% by volume maximum for the main pathways (FT-SPK, ATJ-SOK, and HEFA-SPK certified by ASTM) without requiring any equipment changes, special infrastructure or modification of the supply chain, which helps limit the overall supply chain investments. SAF is an alternative to traditional fossil jet fuel and a promising solution to reduce carbon emissions in the aviation sector. It can be produced from two major sources: • Renewable or waste-derived bio- based resources that meet sustainability criteria depending on their origins, such as renewable oils and fats, lignocellulosic biomass, wastes, sugars, and low carbon intensity inedible starches. • Captured CO₂ combined with renewable hydrogen (produced via water electrolysis using electricity from renewable sources) or low-carbon hydrogen (generated using either nuclear power or fossil natural gas with CO₂ sequestration). Depending on regulations, some traditional hydrogen may or may not be used. This synthetic aviation fuel is known as e-SAF (also known as Power-to-X, synthetic fuels or e-fuels). SAF is considered a drop-in fuel, meaning it can be blended with traditional jet