Today’s sustainable aviation fuel (SAF) is generated from feedstocks that absorb CO2 and provide a net reduction in CO2 across the entire lifecycle of the fuel, when compared to fossil fuels.
To qualify as sustainable, the aviation fuel must:
- be derived from a low-carbon raw material that can be continually and repeatedly sourced. They must not deplete natural resources or compete with other requirements such as food production, land and water use.
- be an alternative to traditional aviation energy sources and be processed to create jet fuel in an alternative manner.
- meet the same rigorous technical requirements and share the same properties as conventional jet fuel, so that they can be blended with other fuel and used in commercial aircraft without requiring changes to existing technology and fuel systems. Safety remains paramount.
Some examples of feedstock that are currently used to produce sustainable aviation fuel include:
- used fats and oils, such as cooking oil and waste from food production
- plants grown in saltwater, including salt marsh grasses
- municipal solid waste, such are product packaging, grass clippings, furniture, clothing, food scraps and newspapers
- cellulosic waste, including excess wood, agricultural waste and forestry residues
- jatropha: a plant whose seeds can be used to produce oil
- algae
- non-food crops grown on marginal land, or in rotation with food crops
- non-biogenic alternative fuels: this typically involves creating jet fuel from carbon sources such as industrial point source waste gases.
Ensuring economically competitive feedstock supply to sustain production remains an ongoing challenge.
The aviation industry is working together through groups such as the Roundtable on Sustainable Biomaterials (RSB) to make sure that any fuels used by the industry are, in fact, sustainable.
By exploring only second-generation biofuels (fuels that can be manufactured from various types of non-food biomass), the aviation industry is determined not to repeat the mistakes made with first-generation fuels in transportation - expecting supplies to be fully sustainable.