3.1. Formation of Coal

You may have seen coal or heard about it. It is as hard as stone and is black in colour. Coal is one of the fuels used to cook food. Earlier, it was used in railway engines to produce steam to run the engine. It is also used in thermal power plants to produce electricity. Coal is also used as a fuel in various industries.

Coal is a solid fossil fuel that has been used for centuries. It is black, hard, and primarily carbon-based. In the past, it was essential for transportation, especially in trains, where it was burned to create steam. Today, coal is crucial for producing electricity, particularly in thermal power plants, and fuels many industries.

Think of coal like the 'bread' of industrial energy. Just as bread serves as a staple food for many people, coal has been a staple energy source that keeps many machines and power plants running.

About 300 million years ago the earth had dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation.

Coal formation is a lengthy process that took place over millions of years. It began with dense forests in wetland areas. When these forests were buried under soil due to natural events, layers of pressure and heat caused the dead plant material to undergo chemical changes. This transformation into coal through heat and pressure is termed carbonisation.

Imagine layering a stack of books. If you kept piling more books on top over many years, the books at the bottom would be crushed under the weight. Similarly, the dead plants, as they were buried deeper and deeper, were pressed and heated until they transformed into coal.

Since it was formed from the remains of vegetation, coal is also called a fossil fuel. A coal mine is shown in the figure. Coal can be processed in industry to get some useful products such as coke, coal tar, and coal gas.

Coal is classified as a fossil fuel because its formation stems from ancient organic matter, specifically trees and plants. This means it is a finite resource we cannot renew easily. In industry, coal isn't just burned for energy; it can be processed further to create products like coke (a key ingredient in steel production), coal tar (used in various industries), and coal gas (used as a fuel).

Consider coal as a multi-purpose ingredient. Just like how flour can be used to make bread, cake, or cookies, coal can be processed into various products that serve different industrial purposes.

Burning of coal produces mainly carbon dioxide gas, which has implications for air pollution and global warming. Therefore, there is a need for sustainable usage and exploring alternatives.

While coal is a valuable resource for energy and industrial processes, burning it releases significant amounts of carbon dioxide, a greenhouse gas contributing to global warming. This presents environmental challenges, necessitating careful and mindful usage of coal resources and the exploration of sustainable alternatives.

Think of coal like a car running on gasoline. While the car can go fast and take you places, it also emits exhaust fumes that pollute the air. Just like the car, we must evaluate the benefits of coal against its environmental costs and seek cleaner options.

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