Why coal is burnt in the absense of oxygen

Carbon dioxide and heat are generated when coal is burnt in the presence of oxygen. - Coal is mainly made out of carbon contents. - So, the combustion of the coal is actually the combustion of carbon. - During this combustion process, the carbon is chemically bonded with the atmospheric oxygen and forms carbon dioxide.

Explanation:

Charcoal is mostly carbon. When it burns, the carbon combines with oxygen from the air to form carbon dioxide and carbon monoxide gases. So, you have fewer oxygen molecules in the air, and instead carbon monoxide and carbon dioxide molecules.  

         The process of heating coal in the absence of air is called the destructive distillation of coal. Coal contains a number of elements such as carbon, hydrogen, oxygen, nitrogen and sulphur. When coal is heated in the absence of air, a number of products are obtained.

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