📘 Q.15 IAS Prelims 2024— Environment (Sustainable Aviation Fuel)🧷 Authentic Classroom Explanation by IAS Monk
📌 The Question:
Consider the following materials:
- Agricultural residues
- Corn grain
- Wastewater treatment sludge
- Wood mill waste
Which of the above can be used as feedstock for producing Sustainable Aviation Fuel (SAF)?
(a) 1 and 2 only
(b) 3 and 4 only
(c) 1, 2, 3 and 4
(d) 1, 3 and 4 only
✅ Correct Answer: (c) 1, 2, 3 and 4
⚡ Lightning Classroom Explanation:
Sustainable Aviation Fuel (SAF) is a low-carbon liquid fuel used in aviation that can reduce lifecycle CO₂ emissions by up to 80% compared to conventional jet fuel.
SAF is feedstock-agnostic and can be produced from a wide spectrum of biogenic and waste-based sources, including:
- 🌾 Agricultural residues (crop stalks, straw)
- 🌽 Corn grain (through alcohol-to-jet pathways)
- 🚰 Wastewater treatment sludge (wet waste conversion routes)
- 🌲 Wood mill waste & forestry residues
All four listed materials fall under approved biomass and waste feedstocks used globally for SAF production.
Hence, all four statements are correct.
🧠 Curiosity Raiser:
👉 SAF made from waste streams can turn pollution liabilities into aviation fuel assets.
📚 Enrich Notes (UPSC Edge):
- SAF pathways include: HEFA, FT-SPK, ATJ, PtL
- Non-food & waste feedstocks are preferred to avoid food vs fuel debate
- SAF is a key pillar of net-zero aviation by 2050
🕊️ IAS Monk Whisper:
“The future of flight may rise not from oil wells, but from what we once called waste.”