Ahmed Matiur Rahman
Peat is not coal. It might be called a step in the process of making coal.
Coal itself is made of the remains of ancient trees and plants that grew in swampy jungles in warm, moist climates hundreds of millions of years ago. These trees and plants fell into the swamp waters. Bacteria changed some parts of the wood into gases that escaped, leaving behind a black mixture, mostly carbon. In time the pressure from mud and sand above squeezed out most of the liquid, leaving behind a pasty mass that slowly transformed into coal.
This process, from beginning to end, took thousands of years. But the first stages of that process of making coal can actually be seen going on today. In the Great Dismal Swamp of Virginia and North Carolina and in thousands of swaps of the northern states of USA and Canada, peat is being made.
In these swamps, plants are gradually decaying in a process that leaves most of the carbon in place. A few years of such action produces a brown, matted mass of twigs, branches, and leaves. This is known as peat. When the water is drained from such a swamp, the peat can be cut into blocks, set out to dry, and then burned as fuel.
Drying in important because peat in the ground may be three fourths water. In Ireland, where peat is plentiful and the higher farms of coal are expensive, more than half of the farms depend entirely on peat for fuel.
The other forms of coal are developments from peat. If peat is allowed to remain where it forms, it gradually changes into lignite, or brown coal. It is more solid than coal, but still soft enough to crumble when shipped long distances.