🔆Coal Gasification

✅The Ministry of Coal has signed the Coal Gasification Plant Development and Production Agreement (CGPDPA) with selected applicants under Category II of the Coal Gasification Financial Incentive Scheme.

📍Coal Gasification?

✅Coal gasification is a thermo-chemical process that converts coal into syngas, a synthetic gas composed mainly of Carbon Monoxide (CO), Hydrogen (H₂), Carbon Dioxide (CO₂), Methane (CH₄), and Water Vapour (H₂O).
✅Coal is reacted at high temperatures (1000–1400°C) with a controlled amount of oxygen and steam, producing syngas.

📍Process of Coal Gasification

✅Preparation: Coal is finely crushed to increase surface area.
✅Gasification reactor: The powdered coal is fed into a reactor with limited oxygen/air and steam.
✅Chemical reactions: Coal breaks down into syngas components due to partial oxidation.
Gas cleaning: Impurities like tar, sulfur, and dust are removed from raw syngas.

📍Ex-situ vs In-situ Gasification
Aspect

✅Ex-situ Gasification
🔰Location: Above ground in controlled gasifiers
🔰Process :Coal is extracted and gasified in reactors
🔰Application :Suitable for shallow reserves
🔰Efficiency :More energy is used in mining and handling

📍In-situ Gasification
🔰Location: Underground, in coal seams
🔰 process: Oxygen and steam are injected into the coal seam to generate syngas underground
🔰Application: Ideal for deep or unmineable coal seams
🔰Efficiency:More energy-efficient for deeper deposits

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🔆 Ozone Depleting Substances (ODSs)
📍 Definition:
✅ Chlorine, bromine, CFCs, carbon tetrachloride, halons, etc.

📍 Potential Drivers of Ozone Hole over Antarctica:
1. Changes in Antarctic polar vortex
2. Changes in solar cycle
3. Increased atmospheric abundance of Chlorofluorocarbons (CFCs)

📍 Polar Vortex
✅ Stratospheric wind patterns with vast low-pressure areas and very cold air, more pronounced over the South Poles.
✅ Leads to formation of Polar Stratospheric Clouds (PSCs).

📍 Impact of Volcanic Eruptions on Ozone Layer:
✅ Triggers massive stratospheric water vapor plume.
✅ Injects large quantities of sulphur dioxide (facilitates chemical conversion of chlorine making it more reactive).
✅ Contributes atmospheric bromine and hydrogen chloride.
✅ Eruption particles provide surfaces for chemical reactions for ODSs.

📍 PSCs (Polar Stratospheric Clouds):
✅ Also known as nacreous clouds or mother of pearl.
✅ Formed below -78°C and trap outgoing longwave radiation.

📍 Location:
✅ Hunga Tonga-Hunga Ha’apai, a submarine volcano in the Tongan archipelago located in the Southern Pacific Ocean, erupted in January 2022.

📍 Ozone Layer Depletion Process (Infographic):
✅ 1st step: UV rays split chlorine atom from CFC molecule.
✅ 2nd step: Chlorine atom breaks up ozone molecule.
✅ 3rd step: The chlorine molecule left behind creates chlorine monoxide and oxygen (O2).

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🔆Tiger reserves : Advantages and disadvantages

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🔆 Clouded Leopard

📍 General Information
✅ Clouded leopard is a wild cat inhabiting dense forests.
✅ It is the state animal of Meghalaya.

📍 Key Facts
✅ Dampa Tiger Reserve (Mizoram) has the highest population density of clouded leopards.
✅ Distribution:
• Bangladesh, Bhutan, China, India, Nepal, and SE Asia.
• In India, it occurs up to Valmiki TR in Bihar.

📍 Conservation Status
✅ IUCN: Vulnerable
✅ CITES: Appendix I
✅ Wildlife Protection Act: Schedule I

🔆Arctic circle

✅The Arctic Circle is a line of latitude at approximately 66.5° North, marking the southern boundary of the Arctic region.

✅It's a crucial geographical feature for understanding solar radiation and the experience of daylight, especially during the solstices.

✅ The Arctic Circle passes through parts of Canada, Russia, Greenland, Norway, Sweden, Finland, Iceland, and the United States (Alaska).

✅Geographical Significance:
The Arctic Circle defines the area where the Sun does not set for at least one day in the summer solstice (June 21) and does not rise for at least one day in the winter solstice (December 21)

✅The Arctic is home to a unique ecosystem, including polar bears, seals, whales, and various species of birds.

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UPSC CALENDAR- 2026
Prelims - 24 May
Mains - 21 Aug.

🔆Dirang Geothermal Well

✅India’s Northeast witnessed a milestone in clean energy as Arunachal Pradesh’s Dirang became home to the region’s first geothermal production well

📍What it is?

✅A renewable geothermal energy project using closed-loop binary Organic Rankine Cycle (ORC) to tap Earth’s subsurface heat for sustainable applications like electricity, heating, and agricultural processing.
✅Location: Situated in Dirang, West Kameng district, Arunachal Pradesh, nestled in the eastern Himalayan terrain.

📍Key Features:

✅Developed by: Centre for Earth Sciences and Himalayan Studies (CESHS), Itanagar
Supported by: Ministry of Earth Sciences, Arunachal Pradesh govt, with global scientific partners from Norway, Iceland, and Guwahati.
✅Temperature Reservoir: ~115°C — ideal for direct-use geothermal technologies.
Low-impact drilling with precision targeting fault zones between quartzite and schist formations.

📍Significance:

✅First such project in Northeast India, with potential to power Dirang entirely via geothermal energy.
✅Reduces dependence on diesel and wood in cold Himalayan climates.
✅Can improve agricultural productivity and quality of life in high-altitude areas.
✅Adds to India’s geothermal potential (~10,600 MW), ensuring base-load renewable power, unlike intermittent sources like solar/wind.

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