Coal is one of the most important and cheapest sources of energy. It is responsible for more than 40% of electricity production worldwide. Coal has played a pivotal role in the progress and development of mankind into the industrial age. It is an essential raw material and fuel for important global industries, such as steel and cement. Different qualities of coal are required for different purposes.
For example, thermal coal is used in production of electricity, while coking coal with higher carbon percentage is used in production of steel. Coal is responsible for almost 1/4 of the global energy production. It is used for many applications, from firing industrial boilers and generators, to producing heat for households to manufacturing cast iron and synthetic fuel. In this article we will discuss all the major uses of coal.
Production of electricity
Coal is frequently used as fuel in order to generate electricity through combustion. In 2015, 6.9 billion tons of coal was consumed and it is expected to increase at around 2% per year in the next two decades. Thermal coal, better known as steam coal, is used in power stations to generate electricity.
Production of steel
The industry of steel is the 2nd largest user of coal, right after the industry of electricity. During 2015, more than six hundred million tons of coal were used in order to produce more than one billion tons of steel. Along with iron, coal is an essential raw material in steel production, which is one of the useful metal products used by humans today. A solid carbonaceous residue, or coking coal, is derived from low-sulfur, low-ash bituminous coal. In order to smelt iron in the furnace, metallurgical coke is used as a fuel. This cast iron is further refined in order to make steel. It is estimated that around 0.64 tons of coke produces one ton of steel.
The cement industry uses coal as an energy source. The production of cement requires large amounts of energy. Kilns normally burn coal in the form of powder and uses around 900g of coal for about 1,800g of cement produced. Many by-products generated from burning coal in coal-fired power plants, such as flue gas desulphurisation gypsum, boiler slag, bottom ash and fly ash are also used in the production of concrete. Cement in concrete can be replaced by using fly ash.
Aluminum industry and paper industry
Both paper industry and aluminum industry require large amounts of fuel and energy. Since coal is the cheapest energy resource it forms an important input to these industries. Additionally, the availability and price of coal is very important factor in the growth of both industries.
Pharma and chemicals industry
There are few chemical products which can be produced from the by-products of coal. Refined coal tar can be used in the manufacturing process of chemicals, such as benzene, phenol, naphthalene, and creosote oil.
Coal liquid and coal gas as transportation fuel
Today, transportation industry doesn’t make much use of coal as fuel. But the increasing cost of oil has made it economical to consider converting coal into gas, which is used to power ships, vehicles, etc.