Coal and Petroleum (original) (raw)

Last Updated : 23 Jul, 2025

**Coal and petroleum are the consequence of the decomposition of ancient plant life that existed millions of years ago. These decomposing plant materials began to accumulate, eventually producing peat. Heat and pressure from geological processes turned these minerals into coal over time. They are also known as fossil fuels because they are made up of essential fossils.

**Coal and Petroleum NCERT class 8 and class 10 are important chapters in the biology syllabus of both these classes. In this article, we will discuss coal and petroleum in detail.

Table of Content

• Fossil Fuels
• Coal
• Formation of Coal
• Properties of Coal
• Types of Coal
• Uses of Coal
• Petroleum
• Petroleum Refining
• Formation of Petroleum
• Uses of Petroleum
• Product of Petroleum

Fossil Fuels

Fossil fuels are flammable geologic deposits of organic matter, such as dead plants and animals, that have been buried beneath thousands of feet of sediment. Due to the intense heat and pressure inside the earth's crust, these deposits decomposed over time and were changed to natural gas, coal, and petroleum. They are also considered non-renewable energy sources because they take a long time to recharge.

**Also Read: Difference Between Renewable And Non-Renewable Resources

Coal

Coal is a blackish or brownish-black sedimentary rock that develops from coal seams, which are a type of start rock. This is thought to have been formed from the algae plants' waste. Coal is mostly composed of carbon, with trace amounts of other organic elements such as hydrogen, sulfur, oxygen, and nitrogen. When dead and rotted plant and animal debris is exposed to the heat and pressure of deep burial for millions of years, it transforms into peat and then coal.

As coal is mined in wetlands, this region is also known as coal woods. The majority of today's coal has been discovered to be significantly younger than the times described. As a fuel, coal rock is always preferable. Despite being utilized for thousands of years, coal was only used in modest quantities until the industrial revolution. Since the invention of the steam engine, the consumption of coal has grown rapidly. Some industrial operations, such as iron and steel manufacture, require the usage of coal.

Coal production and use cause life threatening diseases and sickness. Because coal is a human source of carbon dioxide, which contributes significantly to climate change, its expanding use has serious environmental consequences. Coal combustion will emit around 14.5 billion tonnes of CO2 globally in 2020.

**Formation of Coal

**Coalification is a long-term process that converts dead materials such as plants and flowers into coal. During geological eras, the Earth was once covered in lush woodlands, particularly in wetland areas. In these areas, acidic water and dirt now prevent the decomposition and oxidation of dead plants. Peat is formed as a result of this process. The coalification process began when bogs accumulating peats held significant amounts of carbon, which was later completely buried by sediments.

Now, millions of years of pressure and heat have caused water, carbon dioxide, and methane to escape, leaving the matter with carbon content. The amount of heat and pressure used to turn dead stuff into coal determines the coal's gradation. Sub-bituminous, bituminous, and anthracite coals are generated under high temperature and pressure, whilst Lignite is formed under relatively mild conditions.

Properties of Coal

Some of the properties of coal are discussed below:

**Physical Properties of Coal

• The relative density for the specific gravity of coal is determined by the degree of mineral impurity and the coal's rank. It is critical to have a conceptual understanding of the density of each coal in order to determine the qualities of the composites and blend. The density of the coal seam is required for the conversion of resources into reserves. The relative density is determined by the sample's weight loss in water.
• The particle size distribution of the coal is determined by its rank, which in turn defines its brittleness, as well as the handling, crushing, and milling it has undergone. Because a specific size of coal is required for the furnace and the coke oven, its crush ability must be evaluated and its behavior quantified.

**Chemical Properties of Coal

• As all coals are mined in humid environments, the moisture content is critical. **Adventitious moisture is defined as groundwater and other extraneous moisture that evaporates quickly. The moisture contained within the coals is referred to as intrinsic moisture, and it may be quantified.
• The volatile matter in coal is the component of the coal other than moisture that is freed at high temperatures in the absence of air. It's commonly made up of a mix of long and short-chain hydrocarbons, as well as aromatic hydrocarbons and sulfur.
• Ash is the non-combustible residue that remains after coal has been burned. The bulk substance that remains after the carbon, oxygen, sulfur, and water have been pushed off during conversion is represented by ash. The calculation of the ash percentage is straightforward. When the coal is thoroughly bonded, it is assessed and expressed as a percentage of the original weight. It also gives a good understanding of what coal is like.
• Fixed carbon can be defined as the carbon that remains after all volatile materials have been removed. Because some carbon is lost in hydrocarbons with the volatiles, this differs from coal's ultimate carbon concentration.

**Types of Coal

**Anthracite, bituminous, sub-bituminous, and lignite coal are the four basic forms of coal. The amount and kind of carbon in the coal, as well as its ability to generate heat when burned, are used to rank it.

• **Anthracite: Because it contains around 86–97 percent carbon, it has the highest heating value of all the other coal kinds. Anthracite coal mines are extensively employed in the metal industry.
• **Bituminous: Bituminous coal has a carbon concentration of 45–86 percent. It is the most common form of coal found in the United States. Bituminous coal is utilized to create power since it is an important fuel and raw material for generating coking coal.
• **Sub-Bituminous: Sub-bituminous coal contains 35–45 percent carbon and has a lower heating value than bituminous coal.
• **Lignite: Lignite coal contains roughly 25–35 percent carbon and has the lowest energy content of any known coal variety. Due to its high moisture content, lignite has a low heating value.

**Uses of Coal

• It is used for electricity and power generation in numerous nations due to its low cost.
• Typically, powdered coal is used to generate steam, which then provides high-pressure electricity.
• Coal is also utilized as a raw material in the production of steel and iron, both of which we use every day.
• Coal is readily available in nations such as India and China, and many households, particularly in rural regions, utilize it for activities such as cooking.
• Thermal power generation, which aids in the generation of energy, is a common usage of coal. Powdered coal is burned at a high temperature, which converts water to steam. This steam is utilized to turn turbines at high speeds under a strong magnetic field. Electricity is generated only after that.
• Steel is made indirectly from coal in the steel industry. In this process, coal is cooked in furnaces to make coal coke. Manufacturers use coal coke to smelt iron ore into iron, which is then used to create steel. Meanwhile, ammonia gas from coke ovens is recovered and used to generate nitric acid, ammonia salts, and fertilizers.

**Petroleum

Black Gold is another name for petroleum. Crude oil is used to make gasoline, plastics, pharmaceuticals, synthetic fabrics, and a variety of other items. Petroleum is commonly found as a liquid that forms naturally during the creation of rocks. It is composed of a complicated mixture of hydrocarbon molecules and other chemical compounds. Some chemical compounds derived from petroleum are also derived from fossil fuels.

When petroleum is extracted directly from the ground, it is referred to as crude oil. Despite the fact that humans have been on the planet for over 4000 years, crude oil was first extracted from the ground in China roughly 2500 years ago. Also, after coal, petroleum or mineral oil is the most abundant energy source in India. Petroleum is utilized in the manufacturing industry to provide heat, lighting power, machine lubricants, and raw materials for a variety of other products.

**Petroleum Refining

Petroleum refineries are massive industrial complexes that require a large number of processing units as well as auxiliary structures such as storage tanks and utility units. Petroleum refineries have their own unique set of structures and processes that are required for refining. The location of the refinery, economic circumstances, and the goal products all have a significant impact on this process.

An oil refinery, also known as a petroleum refinery, is a type of industrial manufacturing plant. This is the location where crude oil is extracted and refined into higher-value goods like gasoline, jet fuel, petroleum naphtha, heating oil, asphalt foundation, liquefied gas, and petroleum kerosene.

**Formation of Petroleum

Petroleum is made up of the remains of animals and plants that have died. This occurs when a plant or animal dies and sinks to the ocean floor. After that, it takes millions of years for the organic matter, which is combined with silt and salt, to disintegrate. Different microorganisms also contribute to the breakdown of organic substances. It causes a number of significant chemical changes. Hydrogen and bigger carbon atoms are typically left behind throughout the refining process.

Furthermore, when it arrives at the ocean's depths, the stuff is not sufficiently degraded. This is caused by a shortage of oxygen. It is covered by numerous layers of slip and sand and stays on the seafloor. Millions of years of tremendous pressure and temperature are required for the complete refining process.

**Uses of Petroleum

• LPG, or liquefied petroleum gas, is utilized in the home and in the workplace every day.
• Vehicle fuels include gasoline and diesel. When it comes to big trucks, diesel is the favored fuel.
• In the dry cleaning process, gasoline is used as a solvent. Diesel, on the other hand, can be used as a power generator.
• Kerosene is used to power jet jets and stoves.
• Lubricants help reduce machine wear and tear as well as corrosion.

Product of Petroleum

Some products obtain from the refining of petroleum:

• Diesel Oil
• Gasoline
• Kerosene
• Tar
• Lubricants
• Paraffin Wax

Conclusion - Coal and Petroleum

In conclusion, coal and petroleum, formed over millions of years from decomposed plant and animal matter, are vital resources extensively used in industries and households worldwide. While coal is primarily utilized for electricity generation and steel production, petroleum is a versatile resource used for fuel, plastics, pharmaceuticals, and more. Their significance underscores the need for sustainable practices and the exploration of alternative energy sources to mitigate environmental impacts and ensure long-term energy security.