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 ?
- (a) 1 and 2 only
- (b) 3 and 4 only
- (c) 1, 2, 3 and 4 ✓ UPSC's answer
- (d) 1, 3 and 4 only
Why the answer is (c)
• Sustainable Aviation Fuel (SAF) is jet fuel made from non-petroleum feedstocks that cut life-cycle emissions by up to 80%, and can be blended with conventional fuel.
• Agricultural residues (straw, bagasse) and wood-mill waste supply cellulosic biomass that is converted through gasification or pyrolysis — items 1 and 4 qualify.
• Corn grain is fermented to ethanol and upgraded through the alcohol-to-jet pathway — item 2 qualifies.
• Wastewater treatment sludge and municipal waste yield fats and organic matter convertible to SAF — item 3 qualifies.
• All four are recognised feedstocks; India targets 1% SAF blending in international flights from 2027, option (c).
Why the other options are wrong
- (a) 1 and 2 only
- Sludge and wood waste are also valid SAF feedstocks.
- (b) 3 and 4 only
- Agricultural residues and corn grain are also valid feedstocks.
- (d) 1, 3 and 4 only
- Corn grain is also a feedstock via the alcohol-to-jet route.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.