Methanol (CH₃OH) — “Wood Alcohol”
Simplest alcohol · Low-carbon hydrogen carrier · NITI Aayog Methanol Economy Programme · M15 blending · DME (gaseous form)
Basic Properties & Production
- Chemical formula: CH₃OH | Also called: methyl alcohol, wood alcohol, carbinol | Simplest alcohol | Colourless, flammable liquid at room temperature
- Production feedstocks (India’s key advantage):
- High-ash coal (India has 125 billion tonnes of proven coal reserves — much of it high-ash, not suitable for power plants — but ideal for methanol)
- Biomass (agricultural residues — 500 million tonnes/year in India)
- Municipal Solid Waste (MSW) — waste-to-methanol
- Natural gas + stranded/flared gases
- CO₂ capture from thermal power plants, cement plants, steel plants → combined with green hydrogen to produce Green Methanol
- Energy content: Slightly lower than petrol/diesel — but this is compensated by higher octane rating and cleaner combustion
- Toxicity note: Methanol is TOXIC if consumed (causes blindness/death) — distinguish from ethanol (drinkable alcohol). Requires labelling + coloured dyes when blended.
NITI Aayog Methanol Economy Programme
- Launched: 2016 by NITI Aayog | International Conference on Methanol Economy (Sept 2016)
- Core objectives: Reduce oil import bill | Reduce GHG emissions | Convert high-ash coal + waste into methanol | Create 5 million jobs | Improve urban air quality
- M15 blending (15% methanol in petrol):
- Reduces crude oil imports by at least 15%
- Reduces fuel bill by 30%
- Reduces PM, NOx, SOx by 20%
- M15 blend reduces pollution by 33%
- Minimal vehicle modification needed | Minimal infrastructure change
- M100 (100% methanol fuel): For heavy buses + trucks | Replaces diesel entirely | 80%+ reduction in pollution vs diesel
- NITI Aayog target: Substitute 10% of crude imports using methanol by 2030 (~30 MT methanol needed) | Reduce import bill by ₹6 lakh crore
- Assam Petrochemicals Pilot (2018): India’s first (and Asia’s first) canister-based methanol cooking fuel project | Extended to 1 lakh households in 9 states (UP, Maharashtra, Gujarat, Telangana, AP, Goa, Karnataka, Jharkhand, Manipur)
- Marine application: Cochin Shipyard building boats + cargo vessels for Inland Waterways Authority of India using methanol marine fuel
- Israel partnership: Israel successfully implemented M15 blending program — India studying its model for technology transfer
🔴 DME (Dimethyl Ether) — Latest Current Affairs 2024–25 Latest
- What is DME: Dimethyl Ether (CH₃OCH₃) — the simplest ether | Gaseous form of methanol | Colourless, non-toxic, highly flammable | Used as eco-friendly aerosol propellant, refrigerant (replaces ozone-depleting CFCs), and clean-burning fuel
- CSIR-NCL patent (2024): A research team at CSIR-National Chemical Laboratory (Pune) developed a patent-protected technology for DME production — a major Indian R&D milestone in clean fuel technology
- BIS Standard IS 18698:2024: Bureau of Indian Standards notified IS 18698:2024, permitting blending of up to 20% DME with LPG for domestic, commercial, and industrial use | Up to 8% blending can be done WITHOUT any modification to existing LPG infrastructure (cylinders, regulators, hoses, burners)
- Why DME matters: India imported ~21 million tonnes of LPG in 2024 | Replacing just 8% LPG with DME could save ₹9,500 crore annually in foreign exchange
- Production: DME is produced from methanol (which itself comes from coal/biomass/natural gas/CO₂) | Also from CO₂ capture + green hydrogen → “Green DME”
- Flexible burner prototype: Developed that can operate from 100% LPG to 100% DME, including intermediate blends
- DME as LPG substitute: Emits significantly lower soot, NOx, SOx, and particulate matter than conventional fuels | Thermal efficiency comparable to LPG | Perfect drop-in LPG alternative
LPG — Liquefied Petroleum Gas
Propane (C₃H₈) + Butane (C₄H₁₀) mixture · Stored at ~5–8 bar · PMUY flagship · India imports 21 MT/year
Technical Properties
- Composition: Mainly Propane (C₃H₈) + Butane (C₄H₁₀) mixture | Ratio varies by season (more propane in winter for easier vaporisation)
- Physical state: Gas at atmospheric pressure; liquid when stored under pressure (5–8 bar) at room temperature | Boiling point: Propane −42°C, Butane −1°C
- Storage: Red/orange steel cylinders in India | 14.2 kg cylinders (household); 19 kg (commercial); 5 kg (portable); 47.5 kg (industrial)
- Calorific value: ~46–50 MJ/kg — higher than coal, wood, biogas | Clean combustion with CO₂ + water as products | Very little PM/SOx
- Detection: LPG is odourless — Ethyl Mercaptan (or Thiophane) added as odorant for leak detection (the “gas smell” is this additive, NOT LPG itself)
- India’s LPG import dependence: India imported ~21 million tonnes of LPG in 2024 — making LPG import reduction a major energy security priority
🔴 Pradhan Mantri Ujjwala Yojana (PMUY) — 2024–25 Current Affairs Latest
- Launched: 2016 | Objective: Replace solid/biomass-based polluting cooking fuels with LPG in BPL households | Replaced earlier RGGLV scheme
- Beneficiaries: ~10.35 crore (103.5 million) households as of December 1, 2025 — among the world’s largest clean cooking programmes
- New connections (FY 2025-26): 25 lakh additional LPG connections approved | Simplified eligibility: single “Deprivation Declaration” (replaced earlier multi-point self-declaration)
- Subsidy: ₹300 per 14.2 kg cylinder for up to 9 refills per year for PMUY beneficiaries (targeted subsidy)
- Consumption growth: Average per capita LPG consumption: 2019-20 = ~3 refills/year → FY 2024-25 = 4.47 refills → FY 2025-26 = ~4.85 refills | Significant improvement in adoption
- Safety drive: 12.12 crore free safety inspections at customer premises | 4.65 crore LPG hoses replaced at discounted rates nationwide | Aadhaar-based biometric authentication: 71% PMUY consumers, 62% non-PMUY by Dec 2025
- Piped gas substitution: PNG (Piped Natural Gas) connections = ~1.57 crore (Sept 2025) — PNG replacing LPG cylinders in urban households is a separate trend
LPG vs PNG — Key Comparison
- PNG cheaper: Piped Natural Gas in form of PNG is ~40% cheaper than market price LPG | PNG price almost matches subsidised LPG price
- PNG advantages: No cylinder storage | Continuous supply (like tap water) | More efficient delivery chain (no distributor-agency middle layers) | Safer (no risk of cylinder explosion)
- LPG advantages: Can reach remote areas without pipeline infrastructure | Universal access even in villages | Portable
- National policy: Government expanding PNG through City Gas Distribution (CGD) network — as urban areas get PNG, LPG cylinders vacated for delivery to rural areas
LNG — Liquefied Natural Gas
Methane (CH₄) ~90%+ · Cooled to −162°C · Cryogenic storage · International trade fuel · Maritime + long-haul transport
Technical Properties
- Composition: Primarily Methane (CH₄) — 85–95% | Small amounts of ethane, propane, butane, nitrogen
- Production: Natural gas cooled to −162°C (cryogenic liquefaction) | Volume reduces to 1/600th of gas volume — enabling economical international transport
- Storage: Cryogenic tanks (double-walled, vacuum insulated) | Ships with insulated LNG tanks (LNG carriers) | Regasification terminals at destination ports
- LNG vs CNG: LNG = Liquefied (−162°C, cryogenic); CNG = Compressed (200-250 bar, room temp) | LNG better for long distance; CNG for city use
- Calorific value: ~53 MJ/kg | Methane is cleaner than petrol/diesel — 25% less CO₂ than diesel, negligible PM and SOx
India’s LNG Infrastructure & Sector Applications
- Regasification terminals (major): Dahej (Gujarat, Shell/Total — largest) | Hazira (Gujarat, Shell) | Kochi (Kerala, Petronet LNG) | Ennore (Tamil Nadu, IOC) | Mundra (Gujarat) | Dabhol (Maharashtra) | Jafrabad (Gujarat)
- LNG as transport fuel: Growing use for long-haul trucks and heavy vehicles where CNG has range limitations | LNG trucks can travel 600-1,000+ km on one fill | More economical than diesel for heavy transport
- LNG as maritime fuel: Global shipping moving to LNG to reduce emissions | LNG-powered ships emit 25% less CO₂, 92% less NOx, essentially zero SOx vs heavy fuel oil | India’s coastal shipping looking at LNG bunkering infrastructure
- LNG for industrial use: Where natural gas pipelines haven’t reached | Virtual pipeline concept — LNG trucked to industries, regasified on-site
- LNG in Energy Stations (2024-25): Government setting up 4,000 integrated Energy Stations (2024-29) including LNG dispensing alongside CNG, biofuels, EV charging — creating multi-fuel mobility hubs
- India’s import dependence: India is a major LNG importer — Qatar (Rasgas) is the main supplier under long-term contracts | LNG imports crucial for gas-deficit regions (South India, East India) not connected to gas pipeline grid
CNG — Compressed Natural Gas
Methane compressed at 200–250 bar · 8,400+ stations Sept 2025 · 60% cheaper than petrol · India’s gas-based economy push
Technical Properties & Economics
- Composition: Mainly Methane (CH₄) — 90%+ | Same composition as natural gas, but compressed
- Pressure: Compressed to 200–250 bar (room temperature) | Stored in high-pressure cylinders in vehicles
- Economics (UPSC Key Data):
- CNG is 60% cheaper than petrol and 45% cheaper than diesel
- PNG is 40% cheaper than market-price LPG
- Environmental benefits: 25% less CO₂ than petrol | ~40% less CO than petrol | Near-zero PM and SOx | Lower NOx | Significant urban air quality improvement
- Vehicle adaptation: Dedicated CNG vehicles OR retrofit kits for petrol/diesel vehicles | Kit costs ~₹20,000-35,000 for retrofitting
- Disadvantage: Lower energy density than petrol/diesel → requires larger storage cylinders | Shorter range than petrol vehicles | Refuelling takes longer | Less refuelling infrastructure in rural areas
🔴 CNG/Gas Economy Current Affairs 2025 Latest
- CNG stations: 8,400+ CNG stations across India as of September 2025 | Growing from just a few hundred in 2014
- City Gas Distribution (CGD) network: Expanded to 307 geographical areas (Sept 2025) | Regulated by PNGRB (Petroleum and Natural Gas Regulatory Board)
- PNG connections: ~1.57 crore domestic PNG (Piped Natural Gas) household connections (Sept 2025) | PNG = CNG delivered through pipe, pressurised lower (~0.1 bar)
- Gas pipeline network: Operational pipeline: 25,429 km (June 2025) — up from 15,340 km in 2014 | Under execution: 10,459 km more | Goal: fully connected national gas grid
- One Nation One Grid One Tariff: ~90% of pipelines now under Unified Pipeline Tariff regime — reduces regional price disparities in natural gas
- India’s gas share: Natural gas currently ~6% of India’s energy mix | Government target: 15% (world average = 24%) | Creating a “gas-based economy”
- Integrated Energy Stations (4,000 by 2029): Public sector OMCs setting up multi-fuel mobility hubs offering petrol + diesel + CNG + LNG + biofuels + EV charging | 1,064 operational by November 2025
- CBG blending mandate (FY 2025-26): Compressed Biogas (CBG) blending obligations now mandatory for City Gas Distribution companies in CNG and PNG segments — commencing FY 2025-26 (1%), rising to 5% by 2028
Biogas & Compressed Biogas (CBG)
Anaerobic digestion of organic matter · 55–65% methane · GOBAR-DHAN · SATAT scheme · Bio-CNG · CBG blending mandate FY26
Biogas — What It Is & How It Is Produced
- Composition: 55–65% Methane (CH₄) + 30–40% CO₂ + trace gases (H₂S, N₂, water vapour) | Produced by microbial decomposition of organic matter in absence of oxygen (anaerobic digestion)
- Feedstocks: Cattle/livestock dung | Agricultural crop residues (paddy straw, sugarcane bagasse) | Food waste | Municipal Solid Waste | Sewage sludge | Industrial organic waste | Pressmud from sugar mills
- Biogas plant operation: Organic matter → anaerobic digester (no oxygen) → methane-rich biogas + digestate (nutrient-rich slurry as organic fertiliser) | Digestate = valuable co-product replacing chemical fertilisers
- Traditional biogas: Village-level biogas plants (gobar gas) — cooking + lighting | Relatively low pressure, not stored
- CBG (Compressed Biogas) / Bio-CNG: Biogas purified (CO₂ removed to get 90%+ methane) → compressed to 200-250 bar → identical to CNG | Can be sold through CNG stations and PNG networks
- Why biogas is “cleaner”: Waste-derived fuel (circular economy) | Carbon-neutral (biomass carbon cycle) | Prevents methane emissions from decaying waste (CH₄ is 28x more potent GHG than CO₂) | Creates organic fertiliser as co-product | Decentralised energy production
🔴 GOBAR-DHAN & SATAT — Key Schemes 2024–25 Latest
- GOBAR-DHAN Scheme: Galvanising Organic Bio-Agro Resources for Dhan | Ministry of Jal Shakti | Converts cattle dung (gobar) and farm waste into biogas/CBG and organic fertiliser | Supports rural entrepreneurship and Swachh Bharat | “DHAN” = wealth (from waste to wealth)
- SATAT Initiative: Sustainable Alternative Towards Affordable Transportation | Ministry of Petroleum & Natural Gas | Aims to set up 5,000 CBG plants producing 15 MT CBG/year | Buy-back guarantee by Oil Marketing Companies (OMCs) | Entrepreneurs build CBG plants, OMCs buy all output at pre-agreed prices
- SATAT Progress (Nov 2025): 130+ Compressed Biogas plants commissioned as of November 1, 2025 | Several more under construction | Original target of 5,000 by 2024 is behind schedule but momentum building
- CBG Blending Obligation (CBO) — FY 2025-26 mandate: From FY 2025-26, City Gas Distribution companies are MANDATED to blend CBG in CNG and PNG supply | Start: 1% in FY 2025-26 → rise to 5% by 2028 | Financial assistance provided for pipeline connectivity + biomass aggregation
- Economic potential: Indian Biogas Association: Biogas sector expected to attract Rs 5,000 crore+ investment in 2026-27 | Market expected to expand 2-3 fold | Replacing 20% of natural gas with domestically produced biogas could reduce LNG import costs by $29 billion during 2024-29
- Sustainable Aviation Fuel (SAF) connection: Government has set SAF blending targets: 1% by 2027, 2% by 2028, 5% by 2030 for international flights | IOCL’s Panipat refinery first to get ISCC CORSIA certification for SAF | Bio-based SAF produced from agricultural waste/used cooking oil
- PM JI-VAN Yojana: Pradhan Mantri Jaivik Indhan Vatavaran Anukool Fasal Awashesh Nivaran Yojana | Promotes 2nd Generation (2G) ethanol from agricultural waste | Operational 2G plants at Panipat (Haryana) and Numaligarh (Assam)
📊 Cleaner Fuels — Quick Comparison
| Parameter | Methanol (CH₃OH) | LPG (C₃H₈/C₄H₁₀) | LNG (Mainly CH₄) | CNG (CH₄ compressed) |
|---|---|---|---|---|
| Physical state (storage) | Liquid (room temp) | Liquid under ~8 bar pressure | Liquid at −162°C (cryogenic) | Gas at 200-250 bar |
| Main component | CH₃OH (methanol) | Propane + Butane | Methane (CH₄) ~90%+ | Methane (CH₄) ~90%+ |
| Calorific value | ~22 MJ/kg (lower) | ~46-50 MJ/kg (high) | ~53 MJ/kg (highest) | ~49-53 MJ/kg |
| Primary use in India | Blending (M15) + cooking fuel pilot + marine | Household cooking (dominant) | Power + industrial + maritime + long-haul transport | Vehicles (3W, 4W, buses) + household PNG |
| Key advantage | Cheap feedstock (high-ash coal, waste) + near-zero PM | High calorific value + proven infrastructure | Lowest carbon fossil fuel; best for long-distance transport | 60% cheaper than petrol; 40% less CO₂ vs petrol |
| Key challenge | Lower energy density; TOXIC if ingested; blending infrastructure | High import dependence (21 MT/yr); costly; rural access | Cryogenic storage expensive; needs special ships/tanks | Lower range; needs new infrastructure |
| UPSC-relevant scheme | Methanol Economy Programme (NITI Aayog); DME BIS standard 2024 | PMUY (10.35 cr beneficiaries Dec 2025) | LNG terminals; 4,000 Energy Stations by 2029 | SATAT (CBG mandate); CGD network (307 areas, 8400+ stations) |
| CO₂ vs diesel | ~80% less (when from renewable feedstock) | ~25% less | ~25% less | ~25% less |
⭐ Cleaner Fuels — Complete Cheat Sheet
- Methanol (CH₃OH): Wood/methyl alcohol | Simplest alcohol | TOXIC (≠ ethanol) | Produced from high-ash coal + biomass + MSW + CO₂+H₂ | NITI Aayog Methanol Economy 2016 | M15 = 15% blend with petrol → cuts 15% crude imports, 30% fuel bill, 20% PM/NOx/SOx | M100 = 100% methanol (replaces diesel) | Assam Petrochemicals = first methanol cooking fuel pilot (Asia first, 2018) | DME = gaseous form of methanol
- DME (Dimethyl Ether, CH₃OCH₃): CSIR-NCL patent 2024 | BIS IS 18698:2024 — up to 20% DME blending with LPG allowed | 8% blending without any LPG infrastructure modification | Saves ₹9,500 crore/year fx if 8% LPG replaced | Colourless, non-toxic, highly flammable | CFC replacement aerosol | Green DME from CO₂+green H₂
- LPG: Propane + Butane mixture | Compressed at 5-8 bar | Boiling point: Propane −42°C, Butane −1°C | Ethyl mercaptan added as odorant (that’s the gas smell) | India imports 21 MT/yr | PMUY: 10.35 crore beneficiaries (Dec 2025), ₹300/cylinder subsidy for 9 refills/yr, avg refills rose 3→4.85 | 25 lakh new connections FY26 | 12.12 crore free safety checks | 4.65 crore hoses replaced
- LNG: Methane (90%+) cooled to −162°C | Volume = 1/600th of gas | Cryogenic storage | India terminals: Dahej + Hazira + Kochi + Ennore + Mundra | Long-haul transport fuel (trucks 600-1000 km range) | Maritime fuel (25% less CO₂, near-zero SOx vs heavy fuel oil) | Virtual pipeline = LNG trucked to areas without gas grid
- CNG: Methane compressed at 200-250 bar | 60% cheaper than petrol, 45% cheaper than diesel | 25% less CO₂ vs petrol | 8,400+ CNG stations (Sept 2025) | 1.57 crore PNG connections | 307 CGD areas | 25,429 km operational pipeline (June 2025) | India gas share 6% → target 15% | One Nation One Grid One Tariff
- Biogas/CBG: Anaerobic digestion → 55-65% CH₄ + CO₂ | Feedstock: cattle dung + crop residue + food waste + MSW | Digestate = organic fertiliser | CBG = Compressed Biogas = Bio-CNG (purified + compressed to 200-250 bar) | GOBAR-DHAN = Galvanising Organic Bio-Agro Resources for Dhan (MoJS) | SATAT = Sustainable Alternative Towards Affordable Transportation (MoPNG) — 5,000 CBG plants target, 15 MT/yr | 130+ CBG plants commissioned (Nov 2025) | CBG blending mandate FY26: 1% → 5% by 2028 | $29 billion LNG import savings potential
- Ethanol blending (bonus): 19.24% blend in ESY 2024-25 | ₹1.55 lakh crore cumulative foreign exchange savings | PM JI-VAN Yojana: 2G ethanol from agricultural waste | 2G plants: Panipat (Haryana) + Numaligarh (Assam)
- SAF (Sustainable Aviation Fuel): Targets: 1% SAF in international ATF by 2027, 2% by 2028, 5% by 2030 | IOCL Panipat first Indian company with ISCC CORSIA certification for SAF production
- Energy Stations: 4,000 integrated multi-fuel stations by 2024-29 | Offer: petrol + diesel + CNG + LNG + biofuels + EV charging | 1,064 operational (Nov 2025)
🧪 Practice MCQs
Q1. Consider the following statements about Dimethyl Ether (DME):
1. CSIR-National Chemical Laboratory (Pune) developed a patent-protected technology for DME production in 2024.
2. BIS Standard IS 18698:2024 permits blending of up to 20% DME with LPG without modifying existing LPG infrastructure.
3. Replacing 8% of India’s LPG with DME could save approximately ₹9,500 crore annually in foreign exchange.
4. DME can be produced from CO₂ capture combined with green hydrogen, making it a potential “Green DME.”
Select ALL correct statements:
✅ Answer: (d) All four are correct — key 2024-25 current affairs on DME
1 ✅ CSIR-NCL patent (2024): A research team at CSIR-National Chemical Laboratory (CSIR-NCL) in Pune developed a patent-protected technology for the production of Dimethyl Ether (DME) — a significant Indian R&D achievement in clean fuel technology. DME is a synthetic fuel and potential alternative to LPG as a household cooking fuel. 2 ✅ BIS IS 18698:2024: The Bureau of Indian Standards (BIS) notified IS 18698:2024, permitting blending of up to 20% DME with LPG for domestic, commercial, and industrial use. Crucially, studies indicate that up to 8% DME blending can be done without ANY modification to existing LPG infrastructure (cylinders, regulators, hoses, burners) — making it a ready-to-use, low-cost implementation pathway. 3 ✅ ₹9,500 crore savings: India imported ~21 million tonnes of LPG in 2024. Since this is an imported fuel, replacing even 8% of LPG with domestically-produced DME (from coal or waste) could save approximately ₹9,500 crore annually in foreign exchange — a significant energy security benefit. 4 ✅ Green DME: DME can be produced through multiple pathways: Methanol (from coal/biomass/natural gas) → DME | CO₂ (captured from flue gas of power plants, cement factories) + Green Hydrogen → Methanol → DME. This makes DME a “circular economy” fuel that can be produced from captured carbon, aligning with climate goals.
Q2. Consider the following statements about India’s clean fuel developments in 2025:
1. Under PMUY, approximately 10.35 crore households were covered with LPG access as of December 2025.
2. The natural gas pipeline network reached 25,429 km by June 2025, with CNG stations crossing 8,400 by September 2025.
3. Mandatory CBG (Compressed Biogas) blending in CNG and PNG segments commenced from FY 2025-26.
4. Over 130 CBG plants have been commissioned under the SATAT initiative by November 2025.
Select ALL correct statements:
✅ Answer: (d) All four are correct — from MoPNG Year-End Review 2025 (PIB December 2025)
All four statements are drawn directly from the official Ministry of Petroleum & Natural Gas Year-End Review 2025 (released December 26, 2025). 1 ✅ PMUY 10.35 crore: The Pradhan Mantri Ujjwala Yojana (launched 2016) reached ~10.35 crore beneficiary households as of December 1, 2025, making it one of the world’s largest clean cooking access programmes. An additional 25 lakh connections were approved for FY 2025-26 with simplified “Deprivation Declaration” eligibility. Subsidy: ₹300/cylinder for 9 refills/year. Average refills rose from 3 (2019-20) to 4.85 (projected FY26). 2 ✅ Gas pipeline + CNG stations: India’s operational natural gas pipeline network grew to 25,429 km by June 2025 (from 15,340 km in 2014 — nearly doubled in a decade), with another 10,459 km under construction toward a fully connected national gas grid. CNG stations crossed 8,400 by September 2025, with City Gas Distribution covering 307 geographical areas and ~1.57 crore PNG household connections. 3 ✅ CBG blending mandate FY 2025-26: The government introduced mandatory Compressed Biogas blending obligations for City Gas Distribution companies starting FY 2025-26 — requiring them to blend CBG in CNG and PNG supply. The mandate starts at 1% in FY 2025-26 and is to rise to 5% by 2028, backed by financial assistance for pipeline connectivity and biomass aggregation. 4 ✅ SATAT: 130+ CBG plants (Nov 2025): Under the SATAT (Sustainable Alternative Towards Affordable Transportation) initiative, over 130 Compressed Biogas plants had been commissioned by November 1, 2025 with more under construction. The original target of 5,000 CBG plants producing 15 MT CBG/year is ambitious, but progress is accelerating.
Q3. Consider the following pairs — Fuel : Correct Property/Feature:
1. LPG — Odorant “Ethyl Mercaptan” added for leak detection since LPG itself is odourless
2. LNG — Methane cooled to −162°C, reducing volume to 1/600th of its gas volume
3. CNG — Methane compressed to 200–250 bar, approximately 60% cheaper than petrol
4. Biogas — Contains 55–65% methane produced by anaerobic digestion of organic matter
Select ALL correctly matched pairs:
✅ Answer: (d) All four pairs are correctly matched
1 ✅ LPG + Ethyl Mercaptan: LPG (Liquefied Petroleum Gas — propane+butane mixture) is naturally ODOURLESS and COLOURLESS. If gas leaks, it would be undetectable without an odorant. Ethyl Mercaptan (Methanethiol, C₂H₅SH) — or sometimes Thiophane — is deliberately added in very small quantities (~10-20 ppm) to give LPG its characteristic “rotten egg/gas” smell. This is purely for safety. The smell people associate with “gas leakage” is Ethyl Mercaptan, NOT LPG itself. 2 ✅ LNG at −162°C, 1/600th volume: LNG is produced by cooling natural gas (methane) to −162°C at atmospheric pressure, which liquefies it. The liquid occupies approximately 1/600th the volume of the gas — this massive volume reduction makes international transport economical in specially built LNG carrier ships with cryogenic insulated tanks. At the destination, LNG is regasified at terminals. 3 ✅ CNG — 200-250 bar, 60% cheaper: CNG is methane compressed to 200-250 bar (high pressure) at room temperature, stored in high-pressure cylinders. The economic advantage is significant: CNG costs approximately 60% less than petrol and 45% less than diesel on an energy-equivalent basis. This makes CNG vehicles significantly cheaper to run, especially for taxis, auto-rickshaws, and public buses. 4 ✅ Biogas — 55-65% CH₄, anaerobic digestion: Biogas is produced by the anaerobic digestion (breakdown in absence of oxygen) of organic matter by microorganisms. The biogas produced contains approximately 55-65% methane (CH₄) and 30-40% carbon dioxide (CO₂), along with traces of H₂S and water vapour. When purified (CO₂ removed) and compressed, it becomes CBG (Compressed Biogas) or Bio-CNG, identical to conventional CNG.
These are two different but complementary schemes driving India’s biogas ambitions — and UPSC has tested both. GOBAR-DHAN (Ministry of Jal Shakti): “Galvanising Organic Bio-Agro Resources for Dhan (wealth).” Launched 2018 as part of Swachh Bharat Mission. Focuses on rural areas. Converts cattle dung (“gobar”) and farm/organic waste into biogas and organic fertiliser (digestate). Primarily a RURAL SANITATION + ENERGY ACCESS scheme. Works at village/gram panchayat level. Helps reduce open defecation, improve sanitation, generate local energy from waste. Supports rural entrepreneurship — farmers can earn from selling waste. Integrated with Jal Jeevan Mission water supply programme. Portal connects biogas plant entrepreneurs with buyers, feedstock suppliers, and technology providers. SATAT Initiative (Ministry of Petroleum & Natural Gas): “Sustainable Alternative Towards Affordable Transportation.” Launched October 2018. Focuses on TRANSPORT SECTOR and CITY GAS NETWORKS. Scale: ambitions for 5,000 CBG plants producing 15 MT CBG/year. Key mechanism: Government Oil Marketing Companies (OMCs — Indian Oil, HPCL, BPCL) sign offtake agreements (guaranteed purchase) with CBG plant entrepreneurs at pre-determined prices. This de-risks investment — entrepreneurs know they have a buyer for their output. Target market: blend CBG into CNG and PNG networks. CBG Policy 2025 — Key Framework: CBG Blending Obligation (CBO): CGD companies now MANDATED (from FY 2025-26) to blend CBG — 1% in 2025-26, rising to 5% by 2028. Financial support for pipeline connectivity and biomass aggregation. Status: 130+ CBG plants commissioned (Nov 2025) — behind the 5,000 target, but the blending mandate creates guaranteed demand that should accelerate commissioning. Indian Biogas Association projects Rs 5,000 crore+ sector investment in 2026-27, with 2-3x market growth. The $29 billion LNG import savings potential makes this economically compelling for India’s energy security.
Legacy IAS — UPSC Civil Services Coaching, Bangalore |
Sources: PIB — Year-End Review 2025 MoPNG (Dec 26, 2025: PMUY 10.35 crore, 25,429 km pipeline, 8,400+ CNG stations, 307 CGD areas, 130+ CBG plants SATAT Nov 2025, CBG blending mandate FY26, 4,000 Energy Stations 2024-29, SAF blending targets 2027-2030, IOCL Panipat SAF CORSIA cert, 19.24% ethanol blend ESY 2024-25, ₹1.55 lakh crore FE savings); DD News — MoPNG Year Ender 2025; Millennium Post — MoPNG 2025; Drishti IAS — Year End Review 2025 MoPNG; Khan Global Studies — DME Production India CSIR-NCL patent 2024, BIS IS 18698:2024 (20% DME LPG blending), ₹9,500 crore savings, flexible burner; NITI Aayog — Methanol Economy Programme (NITI.gov.in: M15 blending 15% crude reduction, M100 buses/trucks, 5 million jobs, 2016 launch, Assam Petrochemicals pilot); PIB — Methanol Economy 2018 (M15 reduces pollution 33%, M100 80%+ reduction, Cochin Shipyard methanol boats, Israel M15 model); Biogas India Association — SATAT 5,000 plants target, CBG blending 5% by 2028, Rs 5,000 crore investment 2026-27; Shankar IAS Parliament — PMUY clean cooking fuel; Drishti IAS — SATAT and City Gas Distribution.
