Global Warming

  • Global warming refers to the long-term rise in Earth’s average temperature.
  • It is mainly caused by greenhouse gases like carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O).
  • Burning of fossil fuels is the largest human source of global warming.
  • The greenhouse effect traps heat in the Earth’s atmosphere.
  • Melting of polar ice caps and glaciers is a major impact of global warming.
  • Global warming leads to sea-level rise and extreme weather events.
  • Deforestation increases global warming by reducing CO₂ absorption.
  • The Intergovernmental Panel on Climate Change (IPCC) assesses global warming impacts.
  • Global warming contributes to climate change

Acid Rain

  • Acid rain is precipitation with high levels of sulfuric and nitric acids.
  • It is caused by emissions of sulfur dioxide (SO₂) and nitrogen oxides (NOₓ).
  • Major sources include coal-based power plants and vehicles.
  • Acid rain can occur as rain, snow, fog, or dry deposition.
  • It damages forests, crops, and aquatic ecosystems.
  • Acid rain corrodes monuments and buildings, especially marble.
  • It lowers the pH of soil and water bodies.
  • Taj Trapezium Zone (TTZ) was created to protect the Taj Mahal from acid rain.

Smog

  • Smog is a type of air pollution formed by smoke and fog.
  • There are two main types: Classical smog and Photochemical smog.
  • Photochemical smog forms due to sunlight acting on NOₓ and hydrocarbons.
  • It is common in urban and industrial areas.
  • Smog reduces visibility and causes breathing problems.
  • It irritates the eyes, throat, and lungs.
  • Smog worsens conditions like asthma and bronchitis.
  • The Great Smog of 1952 occurred in London and caused thousands of deaths.

Butane

  • Butane is a flammable hydrocarbon gas with the chemical formula C₄H₁₀.
  • It is a constituent of LPG (Liquefied Petroleum Gas).
  • Butane is mainly used as a fuel in lighters, camping stoves, and aerosol propellants.
  • It is obtained during petroleum refining and natural gas processing.

anaerobic

  • Anaerobic means without oxygen.
  • Anaerobic respiration produces less energy than aerobic respiration.
  • Anaerobic digestion is used in biogas production.
  • Yeast and some bacteria perform anaerobic respiration.

Petroleum

  • Petroleum is a fossil fuel formed from dead organisms over millions of years.
  • It is also known as crude oil.
  • Petroleum is a non-renewable source of energy.
  • Products like petrol, diesel, kerosene, and LPG are obtained from petroleum.

renewable

  • Renewable resources are those that can be replenished naturally.
  • Examples include solar energy, wind energy, and hydropower.
  • Renewable energy sources are environment-friendly.
  • They help in reducing greenhouse gas emissions.

Propane

  • Propane is a hydrocarbon gas with the chemical formula C₃H₈.
  • It is a major component of LPG.
  • Propane is used as a fuel for cooking, heating, and vehicles.
  • It burns cleaner than petrol and diesel.

Methane

  • Methane (CH₄)
  • Methane is the simplest hydrocarbon and the main component of natural gas.
  • Chemical formula of methane is CH₄.
  • Methane is colorless, odorless, and highly inflammable.
  • Methane burns with a blue flame producing CO₂ and H₂O.
  • Methane is a greenhouse gas with high global warming potential.
  • Methane is lighter than air.

volume

  • Volume is the amount of space occupied by a substance.
  • SI unit of volume is cubic metre (m³).
  • Volume of gases changes with temperature and pressure.
  • At STP, one mole of any gas occupies 22.4 litres.
  • Volume is a scalar quantity.

heat

  • Heat is a form of energy transferred due to temperature difference.
  • SI unit of heat is joule (J).
  • Heat always flows from higher temperature to lower temperature.
  • Heat is measured using a calorimeter.
  • Heat is not a state function, it depends on the path.

temperature

  • Temperature is the degree of hotness or coldness of a body.
  • SI unit of temperature is kelvin (K).
  • Temperature is measured by a thermometer.
  • Temperature determines the direction of heat flow.
  • Absolute zero temperature is 0 K or −273.15°C.

Calorific Value

  • Calorific value is the amount of heat produced on complete combustion of 1 kg of fuel.
  • SI unit of calorific value is kJ/kg.
  • Fuels with higher calorific value are more efficient.
  • Methane has a high calorific value (~55,000 kJ/kg).
  • LPG and natural gas have higher calorific value than coal and wood.

LPG

  • LPG (Liquefied Petroleum Gas)
  • LPG is a mixture of propane and butane.
  • It is obtained as a by-product of petroleum refining and natural gas processing.
  • LPG is stored and transported in liquid form under moderate pressure.
  • It is a clean, smokeless, and efficient fuel.
  • LPG has a high calorific value.
  • The main domestic use of LPG is cooking fuel.
  • LPG is heavier than air, so it settles near the ground in case of leakage.
  • The odorant ethyl mercaptan is added to LPG for leak detection.
  • LPG burns with a blue flame due to complete combustion.
  • LPG cylinders are generally painted red in India.

Biogas

  • Biogas is produced by anaerobic decomposition of organic waste.
  • The main component of biogas is methane (CH₄).
  • Biogas also contains carbon dioxide and traces of hydrogen sulfide.
  • Biogas is a renewable source of energy.
  • It is commonly produced from cow dung, sewage, and agricultural waste.
  • Biogas is used for cooking, lighting, and electricity generation.
  • The residue of biogas plants is used as organic manure.
  • Biogas burns with a blue flame.
  • Biogas plants help in waste management and pollution control.
  • Biogas is an eco-friendly and cost-effective fuel.

kerosene

  • Kerosene (Paraffin Oil)
  • Kerosene is a flammable hydrocarbon liquid fuel.
  • It is obtained during fractional distillation of petroleum.
  • It is mainly used as fuel in lamps, stoves, and jet engines (aviation fuel).
  • Kerosene has a higher ignition temperature than petrol.
  • It produces less volatile fumes compared to petrol.
  • In India, kerosene is distributed through the Public Distribution System (PDS).
  • Chemical formula (approx.): C₁₂–C₁₅ hydrocarbons.

petrol

  • Petrol (Gasoline)
  • Petrol is a light, volatile liquid fuel obtained from crude oil.
  • It is mainly used in spark-ignition engines (cars, bikes).
  • Petrol has a low flash point, making it highly inflammable.
  • The octane number measures the quality of petrol.
  • Petrol burns faster than diesel.
  • It is lighter than water and does not mix with water.
  • Leaded petrol is banned in India due to pollution.

diesel

  • Diesel is a heavy petroleum fraction.
  • It is used in compression-ignition engines (trucks, buses, generators).
  • Diesel has a higher flash point than petrol, making it safer to store.
  • The cetane number indicates the quality of diesel.
  • Diesel engines are generally more fuel-efficient than petrol engines.
  • Diesel produces more nitrogen oxides and particulate matter.
  • Diesel oil is less volatile than petrol.

CNG

  • CNG (Compressed Natural Gas)
  • CNG is a clean, gaseous fuel stored under high pressure.
  • Main component of CNG is methane (CH₄).
  • It is used in CNG vehicles and for domestic/industrial purposes.
  • CNG causes less air pollution than petrol and diesel.
  • It has a high calorific value.
  • CNG is lighter than air, so it disperses quickly in case of leakage.

coke

  • Coke is a solid carbon-rich fuel obtained by the destructive distillation of coal.
  • It is produced by heating coal in the absence of air.
  • Coke contains about 90–95% carbon.
  • Coke is hard, porous, and black in appearance.
  • It is an almost pure form of carbon.
  • Coke burns without smoke, making it a clean fuel.
  • Coke has a high calorific value.
  • It is mainly used as a fuel and reducing agent in metallurgy.
  • Coke is widely used in the manufacture of iron in blast furnaces.
  • Coke acts as a reducing agent to extract metals from their ores.
  • It is produced along with coal tar and coal gas as by-products.
  • Coke is insoluble in water.
  • It is stronger and more porous than charcoal.
  • Coke is used in the production of steel.
  • It is an important industrial fuel derived from coal.

natural gas

  • Natural gas is a fossil fuel — mostly methane (CH₄).
    • Methane (CH₄) – ~70–90%
    • Ethane (C₂H₆), Propane (C₃H₈), Butane (C₄H₁₀) – smaller amounts
    • May contain impurities like CO₂, N₂, H₂S, water vapor.
  • It is formed from decomposed organic matter under high pressure and temperature over millions of years.
  • Found in underground rock formations or with oil deposits.

Crude oil

  • Crude oil is a naturally occurring fossil fuel found beneath the Earth’s surface.
  • It is a mixture of hydrocarbons formed from ancient plants and microorganisms.
  • Crude oil is also known as petroleum.
  • It is classified as a non-renewable energy resource.
  • The main products obtained from crude oil are petrol, diesel, kerosene, LPG, and jet fuel.
  • Crude oil is refined in oil refineries through the process of fractional distillation.
  • The unit used for measuring crude oil is barrel (1 barrel = 159 liters).
  • Crude oil prices are mainly quoted in US dollars per barrel.
  • The two major global crude oil benchmarks are Brent Crude and WTI (West Texas Intermediate).
  • Crude oil is a major source of energy and raw material for petrochemical industries.
  • Products like plastics, synthetic fibers, detergents, and fertilizers are derived from crude oil.
  • Crude oil plays a crucial role in transportation, power generation, and industry.
  • India imports most of its crude oil to meet domestic demand.
  • The largest crude oil reserves are found in the Middle East region.
  • Crude oil is transported through pipelines, oil tankers, and railways.
  • Burning crude oil products contributes to air pollution and climate change.
  • Crude oil was first commercially drilled in 1859 in the USA.
  • Petroleum is called “Black Gold” due to its high economic value.
  • The quality of crude oil depends on its API gravity and sulfur content.
  • Low sulfur crude oil is called sweet crude, while high sulfur crude oil is called sour crude.

Coal

  • Coal is a sedimentary rock used mainly as a fuel.
  • Coal is formed from dead plant matter under high pressure and temperature over millions of years.
  • Coal is a non-renewable source of energy.
  • Coal mainly contains carbon, hydrogen, oxygen, nitrogen, and sulfur.
  • four main types of coal
    • Peat – (<28-60%)
    • Lignite/ brown coal – (65-70%)
    • Bituminous – (76-86%)
    • Anthracite (86-97%) –  highest carbon content and calorific value.
  • Coal is an raw material in the iron and steel industry.
  • Coking coal is used to produce coke for blast furnaces.
  • Coal mining is of two types:
    • Open-cast mining
    • Underground mining.
  • Jharia Coalfield is famous for producing high-quality coking coal.
  • Raniganj Coalfield is the oldest coalfield in India.
  • Coal India Limited is a public sector undertaking under the Government of India.
  • Coal reserves are mainly found in Gondwana and Tertiary rock systems in India.
fuel GK