We use wood, cow dung cakes, kerosene (kerosene), bio gas or (LPG) gas in the stove for cooking. Scooters and buses run on diesel, petrol and (CNG) roads. In the fields, the tractor also runs on diesel.

Thermal power plant burn coals to generate electricity. A substance that produces energy (heat) on burning is called fuel. Therefore, wood, cow dung, kerosene, biogas, diesel, coal are called fuel.

Classification of Fuels

According to the physical state of fuels, they are classified as solid, liquid and gas fuels.

1. Solid Fuel

Examples of solid fuels are wood, cow dung, coal, coke and wax. Even today, coal is an important solid fuel. Coal is also called fossil fuel, because millions of years ago, the trees of the forest were buried in the bottom layer of the earth and became coal due to high temperature and high pressure.

Around half of the energy consumed around the world comes from coal. In rural areas, about 80 percent of the required energy is obtained from wood, waste material obtained from agriculture and cow dung. Coal is mostly used in the energy generating and steel industries.

2. Fluid Fuel

Gasoline (Petrol), Kerosene and Diesel are all liquid fuels. These are also called fossil fuels. Millions of years ago, sea creatures and plants were buried in the soil. There was a process of bacteria inside the Earth at high temperature and high pressure, due to which the carbon compounds present in the body of plants and animals were converted into petroleum.

Petroleum is found in the middle of rocks deep inside the earth. Crude petroleum is pumped out of the well by a pump, which is a dark colored fluid, as it is used in many industries. Therefore, is also called black gold. Apart from petrol, other substances from petroleum like petroleum gas, kerosene, diesel, lubricating oil And naphtha are also obtained.

3. Gaseous Fuel

Natural Gas, Coal Gas and LPG (Liquified) Petroleum gases) are gaseous fuels. They are highly flammable and produce a large amount of heat upon burning. Methane is a major component of natural gas. Biogas is obtained by decomposition of dung, plant and fodder. It is a good fuel that is used in villages.