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Q46 (IAS/2024) Science & Technology › New Materials, Energy & Environment-linked Tech › Biofuels and gasification Official Key

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 ?

Result
Your answer: —  ·  Correct: C
Explanation

The correct answer is option C because all four materials—agricultural residues, corn grain, wastewater treatment sludge, and wood mill waste—can serve as feedstock for producing Sustainable Aviation Fuel (SAF).

Sustainable aviation fuel (SAF) is a synthetic fuel produced using non-petroleum feedstocks[1], and the carbon for synthetic fuels comes from biomass residues or seaweed, so-called short-cycle carbon[2]. Biomass is derived from numerous sources, including by-products from the timber industry, agricultural crops, residues from agriculture or forestry, and the organic component of municipal and industrial wastes[3].

Specifically, methanol (a potential SAF component) is produced from agricultural residue[4], confirming Statement 1. Corn grain, as an agricultural crop, falls under biomass feedstock. Anaerobic digestion can be used to treat industrial wastewater sludge, turning it into biogas[5], which can be converted to fuel, validating Statement 3. Pyrolysis of carbonaceous wastes like firewood and saw dust yields products that can be used as fuels[6], confirming Statement 4 regarding wood mill waste. Therefore, all four materials qualify as SAF feedstock.

Sources
  1. [2] https://hydrogen.unido.org/sites/default/files/2024-10/Green-energy-for-all-EN-lr-small.pdf
  2. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 22: Renewable Energy > 22.6 BIOMASS > p. 292
  3. [4] Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 21: Sustainable Development and Climate Change > Methanol Economy > p. 604
  4. [5] https://www.unido.org/sites/default/files/unido-publications/2025-10/ndc-guidebook-vol2.pdf
  5. [6] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > v) Pyrolysis > p. 86
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PROVENANCE & STUDY PATTERN
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Don’t just practise – reverse-engineer the question. This panel shows where this PYQ came from (books / web), how the examiner broke it into hidden statements, and which nearby micro-concepts you were supposed to learn from it. Treat it like an autopsy of the question: what might have triggered it, which exact lines in the book matter, and what linked ideas you should carry forward to future questions.
Q. Consider the following materials : 1. Agricultural residues 2. Corn grain 3. Wastewater treatment sludge 4. Wood mill waste Which of th…
At a glance
Origin: Books + Current Affairs Fairness: Moderate fairness Books / CA: 5/10 · 5/10

This is a classic 'Possibility in Science' question. The keyword 'can be used' signals a test of technological potential, not just current commercial dominance. Since SAF technologies (like Gasification and Alcohol-to-Jet) are designed to be feedstock-agnostic for any carbon-based waste, the scope is naturally broad.

How this question is built

This question can be broken into the following sub-statements. Tap a statement sentence to jump into its detailed analysis.

Statement 1
Can agricultural residues be used as a feedstock for producing Sustainable Aviation Fuel (SAF)?
Origin: Direct from books Fairness: Straightforward Book-answerable
From standard books
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 23: India and Climate Change > Sources ofBio - Energy > p. 307
Presence: 5/5
“• Existing Sources • Leftover organic residue • Leftover farm organic residue • Leftover forest residue • Leftover organic urban residue • Algal residue • New Sources • Cultivation of short rotation energy crops • Social forestry”
Why this source?
  • Explicitly lists 'leftover farm organic residue' as an existing source of bio-energy.
  • Groups farm residues with other organic leftovers as usable feedstocks for energy production.
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 22: Renewable Energy > 22.6 BIOMASS > p. 292
Presence: 4/5
“Biomass is a renewable energy resource derived from the carbonaceous waste of various human and natural activities. It is derived from numerous sources, including the by-products from the timber industry, agricultural crops, grassy and woody plants, residues from agriculture or forestry, oil-rich algae, and the organic component of municipal and industrial wastes. Biomass is a good substitute for the conventional fossil fuels for heating and energy generation purposes. Burning biomass releases about the same amount of carbon dioxide as burning fossil fuels, However, fossil fuels release carbon dioxide captured by photosynthesis over its formative years.”
Why this source?
  • Defines biomass to include residues from agriculture and forestry as inputs for renewable energy.
  • Frames biomass as a substitute for conventional fossil fuels, implying conversion of residues into fuels.
Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 21: Sustainable Development and Climate Change > Methanol Economy > p. 604
Presence: 4/5
“Methanol is a low-carbon, hydrogen carrier fuel. It is produced from high ash coal, agricultural residue, CO<sub>2</sub> from thermal power plants, etc. Methanol Economy program is initiated by NITI Aayog. It is aimed to reduce import of crude oil and reduce GHG emissions. It also intends to convert coal reserves and municipal solid waste into methanol and set up Methanol Production Plants. Blending of 15 per cent methanol in gasoline can result in at least 15 per cent reduction in import of gasoline/crude. It will reduce GHG emissions by 20 per cent in terms of particulate matter, NO<sub>x</sub> and SO<sub>x</sub>.”
Why this source?
  • States methanol can be produced from agricultural residue, showing residues are convertible into transport fuels.
  • Links residue-derived fuels to low-carbon fuel strategies and national fuel programs.
Statement 2
Can corn grain be used as a feedstock for producing Sustainable Aviation Fuel (SAF)?
Origin: Web / Current Affairs Fairness: CA heavy Web-answerable

Web source
Presence: 4/5
"On the desert sands one can grow trees for wood production, but also fruit trees, olive trees, and grains. ... It would also be interesting to plant fast- growing crops like elephant grass, which can be used as a feedstock for a number of bio-chemical products and synthetic fuels."
Why this source?
  • Explicitly lists 'grains' among crops that can be grown and points to using fast‑growing crops as feedstock for synthetic fuels.
  • Links agricultural grains and crop biomass to production pathways for synthetic fuels, which includes SAF.
Web source
Presence: 4/5
"Aviation will need synthetic aviation fuel, also known as sustainable aviation fuel (SAF), ... The carbon for synthetic fuels can’t be derived from recycling, so that it will come from biomass residues or seaweed, so-called short-cycle carbon."
Why this source?
  • Defines aviation fuel needs as 'synthetic aviation fuel, also known as sustainable aviation fuel (SAF)'.
  • States the carbon for synthetic fuels will come from biomass residues or seaweed (i.e., short‑cycle biomass sources).
Web source
Presence: 3/5
"Sustainable aviation fuel, known as SAF, is a synthetic fuel that is produced using non-petroleum feedstocks."
Why this source?
  • Defines SAF as a synthetic fuel produced using non‑petroleum feedstocks.
  • Supports the general claim that non‑petroleum biomass (such as crops/grains) can serve as SAF feedstocks.

Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 6: Environmental Issues > Who are behind developing GE trees and why? > p. 123
Strength: 5/5
“It is ArborCen, a subsidiary of Monsanto, and oil companies like British Petroieum and Chevron that are investing in this technology. For these companies, GE trees offer a viable alternative to fossil fuels as GE trees could produce ethanol, a green fuel. As the ethanol produced from food stocks came under attack, the companies see a bright future in non-food cellulose feedstock like GE trees.”
Why relevant

Says ethanol is produced from food stocks and that companies considered food-based ethanol as a fuel before shifting interest to non-food cellulose feedstocks.

How to extend

A student could note that if food crops can be fermented to ethanol (a fuel), similar crops might be convertible to other liquid fuels or intermediates used in SAF pathways, and then check technology routes (e.g., fermentation + upgrading).

Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > Biomass fuels or biofuels > p. 425
Strength: 5/5
“• A fuel produced from dry organic matter or combustible oils produced by plants. • These fuels are considered renewable as long as the vegetation producing them is maintained or replanted, such as firewood, alcohol fermented from sugar, and combustible oils extracted from soy beans. • Their use in place of fossil fuels cuts greenhouse gas emissions because the plants that are the fuel sources capture carbon dioxide from the atmosphere.”
Why relevant

Defines biofuels as fuels produced from plant-derived alcohols and plant oils, citing alcohol fermented from sugar as an example.

How to extend

A student could connect that corn can yield fermentable sugars/starches and thereby alcohols, which could potentially be upgraded or co-processed toward drop-in transport fuels like SAF.

Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Maize or Corn (Zea Mays) > p. 23
Strength: 4/5
“It is cultivated in about 8 million hectares under a wide range of agro-ecological situations. It contributes nearly 8% in the national food basket. In addition to staple food for human being and quality feed for animals, maize serves as a basic raw material as an ingredient to thousands of industrial products that include starch, oil, protein, alcoholic beverages, food sweeteners, pharmaceutical, cosmetic, flm, textile, gum, package and paper industries etc. Maize is cultivated throughout the year in diferent parts of the country for various purposes including grain, fodder, green cobs, sweet corn, baby corn, pop corn etc.”
Why relevant

Lists maize uses including starch, oil and alcoholic beverages — indicating corn is an industrial feedstock for producing alcohol and oil.

How to extend

A student could infer that corn grain’s starch-to-alcohol processing is an established industrial route that might feed into fuel production chains relevant to SAF (e.g., ethanol-to-jet or biochemical upgrading).

Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 26: Agriculture > 3. MAIZE/CORN (Fig. 26.10) > p. 253
Strength: 4/5
“(a) Maize originated in America as Indian corn. The corn is ground to make maize mcal (Mealie), but is not good for bread-making. (b) Has many varieties. Dent is soft maize, and flint is hard maize. Also eaten as sweet corn, pop corn, and many new hybrids give better yields. (c) Many uses: food-crop, animal fattening, cornflakes, alcohol distilling, etc. Barley, Rye, Oats, Millet. These are the more hardy cereals of secondary importance. Tolerant of inferior soil. less favourable climate. More interior and continental regions, even of”
Why relevant

Specifically notes maize is used for alcohol distilling, i.e., conversion of maize to ethanol/alcohol is a known use.

How to extend

A student could use the known maize→ethanol fact and then research whether ethanol can be converted or upgraded to jet-range hydrocarbons or used in SAF pathways.

Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > v) Pyrolysis > p. 86
Strength: 3/5
“It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels. Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoai along with products like tar, methyl alcohol, acetic acid, acetone and a fuel gas.”
Why relevant

Describes pyrolysis of corn cobs (corn combs) producing combustible liquids and gas — an example of converting corn residues into fuel products.

How to extend

A student could extend this by distinguishing grain vs. residue feedstocks and exploring whether grain (or residues) can be thermochemically upgraded to jet-range fuels used as SAF.

Statement 3
Can wastewater treatment sludge be used as a feedstock for producing Sustainable Aviation Fuel (SAF)?
Origin: Web / Current Affairs Fairness: CA heavy Web-answerable

Web source
Presence: 4/5
"Anaerobic digestion can be used to treat industrial wastewater sludge, turning it into biogas (mainly methane) and digestate."
Why this source?
  • Directly describes converting wastewater sludge via anaerobic digestion into biogas, a fuel feedstock.
  • Mentions biogas upgrading systems, which can refine biogas into higher‑value gaseous/liquid fuels.
Web source
Presence: 4/5
"you can convert biomass streams in the future into bio-hydrogen and bio-carbon dioxide. Hydrogen can be used as feedstock and as an energy carrier; carbon dioxide can be used as a feedstock for products, for which we currently still use fossil carbon,"
Why this source?
  • States biomass streams can be converted into bio-hydrogen and bio-carbon dioxide.
  • Specifies carbon dioxide can be used as a feedstock for products and synthetic fuels (i.e., non‑fossil carbon feedstock).
Web source
Presence: 4/5
"Alternatively, you can also liquefy the CO2, and then transport it by (hydrogen-fueled) tank truck to a chemical company or synthetic fuel producer, where it will be used as a feedstock."
Why this source?
  • Describes transporting captured CO2 to chemical or synthetic fuel producers where it is used as a feedstock.
  • Links captured CO2 (which could originate from waste/biomass processes) to synthetic fuel production pathways.

Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Marine Pollution Control > p. 47
Strength: 4/5
“A number of preventive and technological steps have been suggested by the experts of oceanography and ecology. Some of the important steps are described briefy in the following: • 1. Treatment of sewage: Tere should be installation of treatment plants along the drains which discharge liquid and solid wastes into the bays and sea.• 2. Sludge Processing: Te sludge contains pollutants and harmful bacteria should be treated before it is discharged into the seas, gulfs, and oceans.• 3. Seepage oil-proof tankers: Te loading and unloading of crude oil and petroleum in the tankers should be through the 'top load system'.”
Why relevant

Mentions 'Sludge Processing' and that sludge contains pollutants and must be treated before discharge — indicating sludge is a recognized waste stream that is processed rather than simply discarded.

How to extend

A student could combine this with knowledge of conversion pathways to ask whether treated sludge (post-decontamination) has the physical/chemical properties required for fuel conversion.

Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > Biomass fuels or biofuels > p. 425
Strength: 5/5
“• A fuel produced from dry organic matter or combustible oils produced by plants. • These fuels are considered renewable as long as the vegetation producing them is maintained or replanted, such as firewood, alcohol fermented from sugar, and combustible oils extracted from soy beans. • Their use in place of fossil fuels cuts greenhouse gas emissions because the plants that are the fuel sources capture carbon dioxide from the atmosphere.”
Why relevant

Defines biofuels as fuels produced from dry organic matter or combustible oils from plants, establishing the general rule that organic/biomass matter can be converted into fuels.

How to extend

A student could apply this rule to sludge by checking whether sludge contains sufficient organic/biomass content (or extractable oils) to qualify as a feedstock for biofuel conversion.

Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > v) Pyrolysis > p. 86
Strength: 5/5
“It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels. Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoai along with products like tar, methyl alcohol, acetic acid, acetone and a fuel gas.”
Why relevant

Describes pyrolysis of carbonaceous wastes producing liquid and gaseous fuel products, giving an example of a thermochemical conversion route that turns waste biomass into fuel-like liquids.

How to extend

A student could investigate whether wastewater sludge is sufficiently carbonaceous and dryable to undergo pyrolysis or related thermochemical processes to yield fuel precursors for SAF.

Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 8: Energy Resources > Bio-Energy > p. 30
Strength: 4/5
“Bio-energy is a clean source of energy which improves sanitation, hygiene and the living style of the rural population. The technique is based on the decomposition of organic matter in the absence of air to produce gas. Bio-gas is used for cooking, and lighting fuel in specially designed stove and lamps respectively. According to one estimate, India has a capacity to produce biogas to the extent of 25,000 million cubic m. The left over digested slurry serves as manure. This can meet 50% of the rural domestic fuel requirements. Moreover, it can produce 7 million tonnes to nitrogen, 3 million tonnes phosphate, 5 million tonnes of potassium, and over 50 million tonnes of compost manure.”
Why relevant

Explains bio-energy from anaerobic decomposition of organic matter producing biogas and a digested slurry byproduct, showing biochemical conversion of organic wastes into usable fuels.

How to extend

A student could consider biochemical routes (anaerobic digestion, followed by upgrading) or use of digestion residues as feedstock for further processing toward hydrocarbon fuels.

Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Microbes as a source of biogas > p. 20
Strength: 4/5
“Many microorganisms, like bacteria and fungi, live in an oxygenfree environment. Some of these bacteria have the ability to decompose plant and animal waste present in the environment or household wastewater. During the process, they release a mixture of gases containing carbon dioxide, and a high proportion of another gas, methane. This gas has been used as a fuel source for cooking, heating, generating electricity, and to even run vehicles.”
Why relevant

Notes that microbes decompose household wastewater and release methane-rich biogas, demonstrating that wastewater contains biodegradable organics convertible into fuel gases.

How to extend

A student could extend this by checking if gasification/biogas-upgrading plus downstream synthesis (e.g., Fischer–Tropsch or hydroprocessing) could convert such gaseous/biomass outputs into jet-range hydrocarbons.

Statement 4
Can wood mill waste be used as a feedstock for producing Sustainable Aviation Fuel (SAF)?
Origin: Direct from books Fairness: Straightforward Book-answerable
From standard books
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > v) Pyrolysis > p. 86
Presence: 4/5
“It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels. Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoai along with products like tar, methyl alcohol, acetic acid, acetone and a fuel gas.”
Why this source?
  • Explicitly lists saw dust among carbonaceous wastes subject to pyrolysis.
  • Describes pyrolysis producing liquid and gaseous fuels (tar, methanol, fuel gas) from saw dust.
  • Demonstrates a thermochemical route that converts wood mill waste into fuel intermediates usable as feedstock.
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 22: Renewable Energy > 22.6 BIOMASS > p. 292
Presence: 4/5
“Biomass is a renewable energy resource derived from the carbonaceous waste of various human and natural activities. It is derived from numerous sources, including the by-products from the timber industry, agricultural crops, grassy and woody plants, residues from agriculture or forestry, oil-rich algae, and the organic component of municipal and industrial wastes. Biomass is a good substitute for the conventional fossil fuels for heating and energy generation purposes. Burning biomass releases about the same amount of carbon dioxide as burning fossil fuels, However, fossil fuels release carbon dioxide captured by photosynthesis over its formative years.”
Why this source?
  • Defines biomass as including by-products from the timber industry.
  • States biomass is a renewable substitute for conventional fossil fuels.
  • Places timber by-products within the pool of materials usable for energy production.
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > Biomass fuels or biofuels > p. 425
Presence: 3/5
“• A fuel produced from dry organic matter or combustible oils produced by plants. • These fuels are considered renewable as long as the vegetation producing them is maintained or replanted, such as firewood, alcohol fermented from sugar, and combustible oils extracted from soy beans. • Their use in place of fossil fuels cuts greenhouse gas emissions because the plants that are the fuel sources capture carbon dioxide from the atmosphere.”
Why this source?
  • Defines biofuels as fuels produced from dry organic matter or plant-derived oils.
  • Notes substitution of fossil fuels by plant-based fuels and associated GHG benefits.
  • Classifies plant/wood-derived organic matter as valid feedstock for producing renewable fuels.
Pattern takeaway: In Science & Tech 'Application' questions, if the technology is emerging (like SAF, Green Hydrogen, or Carbon Nanotubes) and the options are organic/plausible inputs, the answer is almost always 'All of the above'. UPSC tests the *potential* of the technology, not the *profitability*.
How you should have studied
  1. [THE VERDICT]: Medium/Logical Sitter. While specific books list 'biomass' generally, the specific application to SAF requires linking static concepts (Corn -> Ethanol) to current tech (Ethanol -> Jet Fuel).
  2. [THE CONCEPTUAL TRIGGER]: Biofuels & Alternative Energy (GS-3). Specifically, the transition from 1st Gen (Edible) to 2nd Gen (Residues/Waste) biofuels.
  3. [THE HORIZONTAL EXPANSION]: Memorize the 4 main ASTM-approved SAF pathways: 1. HEFA (Oils/Fats/Grease), 2. Alcohol-to-Jet (Corn/Sugarcane/Biomass), 3. Fischer-Tropsch (Ag residue/Wood waste/Sludge), 4. Power-to-Liquid (CO2 + Green Hydrogen). Know the difference between 1G, 2G, 3G (Algae), and 4G (Genetically Modified) biofuels.
  4. [THE STRATEGIC METACOGNITION]: Chain Logic is required. Don't stop at 'Corn makes Ethanol'. Ask: 'Can Ethanol be upgraded to Jet Fuel?' (Yes). Don't stop at 'Sludge makes Methane'. Ask: 'Can Methane be liquefied to fuel?' (Yes). If the raw material has Carbon and Hydrogen, modern chemistry *can* likely turn it into fuel.
Concept hooks from this question
📌 Adjacent topic to master
S1
👉 Biomass feedstock classification
💡 The insight

Agricultural residues are part of the biomass category used as feedstock for producing renewable fuels.

High-yield for questions on renewable energy and biofuels; links natural-resource categories to energy policy and technological options. Mastering this helps answer queries on what counts as biofuel feedstock and policy choices for sustainable energy.

📚 Reading List :
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 22: Renewable Energy > 22.6 BIOMASS > p. 292
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 23: India and Climate Change > Sources ofBio - Energy > p. 307
🔗 Anchor: "Can agricultural residues be used as a feedstock for producing Sustainable Aviat..."
📌 Adjacent topic to master
S1
👉 Agricultural residues as energy resources
💡 The insight

Leftover farm organic material and crop by-products (e.g., bagasse) are identified as usable fuels or inputs for fuel production.

Important for questions connecting agriculture, rural livelihoods and energy security; useful for essays and mains answers on circular economy, agro-waste management and renewable energy deployment.

📚 Reading List :
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 23: India and Climate Change > Sources ofBio - Energy > p. 307
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 25: Agriculture > Sugar Crops > p. 353
🔗 Anchor: "Can agricultural residues be used as a feedstock for producing Sustainable Aviat..."
📌 Adjacent topic to master
S1
👉 Residue-to-fuel pathways (example: methanol)
💡 The insight

Agricultural residues can be chemically converted into transport fuels such as methanol, demonstrating viable conversion pathways.

Enables candidates to discuss concrete fuel-production routes and policy initiatives (e.g., methanol economy), linking technology to emissions and import-reduction strategies. Useful for analytical answers on alternative fuels and blending policies.

📚 Reading List :
  • Indian Economy, Nitin Singhania .(ed 2nd 2021-22) > Chapter 21: Sustainable Development and Climate Change > Methanol Economy > p. 604
🔗 Anchor: "Can agricultural residues be used as a feedstock for producing Sustainable Aviat..."
📌 Adjacent topic to master
S2
👉 Maize as an industrial feedstock
💡 The insight

Maize is used to produce industrial products including alcohol and oils, which are feedstocks that can be transformed into fuels.

High-yield: links agriculture with industrial processing and energy policy; helps answer questions on crop-based industries, value chains, and the food-versus-fuel debate. Useful across GS paper topics on agriculture, industry and environment.

📚 Reading List :
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Maize or Corn (Zea Mays) > p. 23
  • Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 26: Agriculture > 3. MAIZE/CORN (Fig. 26.10) > p. 253
🔗 Anchor: "Can corn grain be used as a feedstock for producing Sustainable Aviation Fuel (S..."
📌 Adjacent topic to master
S2
👉 Biofuels and biological feedstocks
💡 The insight

Biofuels are fuels derived from plant organic matter such as alcohol from sugars and oils from oilseeds, directly relating crop products to fuel production.

Essential for questions on renewable energy policy, climate mitigation and sustainable resource use; connects energy, environment and agricultural policy analysis. Enables evaluation of feedstock choices and sustainability trade-offs.

📚 Reading List :
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > Biomass fuels or biofuels > p. 425
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Maize or Corn (Zea Mays) > p. 23
🔗 Anchor: "Can corn grain be used as a feedstock for producing Sustainable Aviation Fuel (S..."
📌 Adjacent topic to master
S2
👉 Conversion processes: fermentation and pyrolysis
💡 The insight

Fermentation yields alcohol from plant sugars and pyrolysis produces liquid products from biomass components like corn residues, showing technological routes from corn to fuels.

Valuable for assessing technological feasibility and environmental implications of bioenergy pathways; helps answer questions on technology-policy linkages and impacts of adoption at scale.

📚 Reading List :
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > v) Pyrolysis > p. 86
  • Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 29: Environment Issues and Health Effects > Biomass fuels or biofuels > p. 425
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Maize or Corn (Zea Mays) > p. 23
🔗 Anchor: "Can corn grain be used as a feedstock for producing Sustainable Aviation Fuel (S..."
📌 Adjacent topic to master
S3
👉 Waste-to-energy: Anaerobic digestion and biogas
💡 The insight

Anaerobic decomposition of wastewater produces biogas that can be used as a fuel, showing wastewater/sludge can be converted into energy carriers.

High-yield for environment and energy questions: links sanitation, renewable energy, and circular economy. Helps answer questions on bioenergy potentials, decentralized energy solutions, and sustainable urban infrastructure.

📚 Reading List :
  • Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Microbes as a source of biogas > p. 20
  • Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 8: Energy Resources > Bio-Energy > p. 30
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > ix) Landfills > p. 53
🔗 Anchor: "Can wastewater treatment sludge be used as a feedstock for producing Sustainable..."
🌑 The Hidden Trap

CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). UPSC will likely ask about the 'baseline' years or the voluntary vs. mandatory phases of this ICAO scheme next, given the focus on SAF.

⚡ Elimination Cheat Code

The 'Organic Carbon Rule': In questions asking if Material X can be a feedstock for Biofuel/SAF, if Material X is organic (contains Carbon) and is a waste/plant product, the answer is YES. Technology (Pyrolysis/Gasification) exists to convert almost any biomass into hydrocarbons. Do not eliminate unless the material is inorganic (like sand or glass).

🔗 Mains Connection

Economy & Security: Link SAF not just to Environment, but to 'Import Substitution' (reducing the Oil Import Bill) and 'Circular Economy' (Waste-to-Wealth). This is a key argument for Mains answers on Energy Security.

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SIMILAR QUESTIONS

IAS · 2019 · Q35 Relevance score: 0.10

Consider the following : 1. Carbon monoxide 2. Methane 3. Ozone 4. Sulphur dioxide Which of the above are released into atmosphere due to the burning of crop/biomass residue?

IAS · 2008 · Q19 Relevance score: -1.91

Consider the following: 1. Rice fields 2. Coal mining 3. Domestic animals 4. Wetlands Which of the above are sources of methane, a major greenhouse gas?

IAS · 2018 · Q97 Relevance score: -2.44

Consider the following items : 1. Cereal grains hulled 2. Chicken eggs cooked 3. Fish processed and canned 4. Newspapers containing advertising material Which of the above items is/are exempted under GST (Goods and Services Tax) ?

IAS · 2025 · Q45 Relevance score: -2.99

Consider the following substances: 1. Ethanol 2. Nitroglycerine 3. Urea Coal gasification technology can be used in the production of how many of them?

IAS · 2014 · Q73 Relevance score: -3.28

Consider the following statements : 1. Maize can be used for the production of starch. 2. Oil extracted from maize can be a feedstock for biodiesel. 3. Alcoholic beverages can be produced by using maize. Which of the statements given above is/are correct?