Difference Between Coal and Coke

Coal vs Coke
 

Coal and coke are common fuels used for household and industrial combustion purposes. Both are present in the natural environment. However, coke is produced by man for the excessive usage.

Coal

Coal is a fossil fuel similar to natural gas and oil, which is in a solid rock form. Coal is formed by accumulating plant debris in swamps. The process takes thousands of years. When plant materials collect on swamps, they degrade very slowly. Normally swamp water doesn’t have high oxygen concentration; therefore, microorganism density is low there, resulting in minimum degradation by microorganisms. Slow decaying of plant debris allows them to accumulate more in the swamps. When these are buried under sand or mud, the pressure and inside temperature convert the plant debris to coal slowly. To accumulate a large number of plant debris and for decaying process, it takes a long time. Further, there should be suitable water levels and conditions to make this favorable. Thus, coal is considered as a nonrenewable natural resource. This is because, when coal is mined out and used, they cannot be regenerated again easily.

There are different types of coal. They are ranked based on their properties and composition. Such coal types are peat, lignite, sub bituminous, bituminous and anthracite. Peat is the lowest type of coal in the ranking list. It is formed from recently accumulated plant debris and with further time, can be converted to coal.

Main economic usage of coal is to produce electricity. By burning coal, heat is obtained and then this heat energy is used to produce steam. Finally, electricity is produced by running a steam generator. Other than generating electricity, coal is used for generating power in many other occasions. From very earlier times, coal was used in factories, to run trains, as a household energy source etc. Moreover, coal is used to produce coke, synthetic rubber, insecticides, paint products, solvents, medicine etc.

Coke

Coke is a naturally found carbonaceous solid, but it can be made by man too. Man-made coke is used commonly.

Coke has a hard, porous structure, and it is grey in color. It is produced from bituminous coal. Coal is baked in an airless furnace at a very high temperature (above 2000 degrees Celsius) to remove water, gas and coal-tar, and at the end of the coking process, it contains zero amount of water. However, later small amount of water can be absorbed by the porous structure.

Coke is useful as a fuel in stoves and furnaces. It burns with no smoke; therefore, better as a fuel than bituminous coal itself. Coke is also used as a reducing agent in smelting iron ore.