Q. Consider the following materials :

  1. Agricultural residues
  2. Corn grain
  3. Wastewater treatment sludge
  4. Wood mill waste

Which of the above can be used as feedstock for producing Sustainable Aviation Fuel?

  • 1 and 2 only
  • 3 and 4 only
  • 1, 2, 3 and 4
  • 1, 3 and 4 only

Answer: (c) 1, 2, 3 and 4

Sustainable Aviation Fuel: 
  • Sustainable Aviation Fuel (SAF) is also known as bio-jet fuel.
  • It is made from renewable biomass and waste resources have the potential to deliver the performance of petroleum-based jet fuel. 
  • It is a “drop-in” fuel that can be blended up to 50% with traditional jet fuel.
  • Itis a liquid fuel currently used in commercial aviation which reduces CO2 emissions by up to 80%.
  • Production: It can be produced from a number of sources (feedstock) including waste oil and fats, green and municipal waste and non-food crops.
    • It can be produced from various sources, including palm stearin, sapium oil, palm fatty acid distillates, algae oil, karanja, and jatropha.
    • It can also be produced synthetically via a process that captures carbon directly from the air.
  • Significance:
    • Its carbon footprint is significantly lower than aviation turbine fuel (ATF).
    • It is ‘sustainable’ because the raw feedstock does not compete with food crops or water supplies, or is responsible for forest degradation. 
    • It remains the major mature and viable pathway to decarbonise the aviation sector. At the same time, SAF only accounts for 0.3% of the current fuel use for aviation.
    • In contrast to fossil fuels, which release carbon that was previously locked up, SAF recycles the CO2 that has been absorbed throughout the course of the life of the biomass utilized as the feedstock.
    • It can be used in existing aircraft engines without modifications and can be blended with conventional jet fuel, making it relatively easy to integrate into existing aviation infrastructure.
  • Challenges associated:
    • Four times more expensive than traditional fossil jet fuel.
    • Scarcity of waste based feedstock.
    • Lower energy density than traditional jet fuel.
Sustainable Aviation Fuel (SAF)