What is destructive distillation of coal

Destructive distillation may be a chemical change during which decomposition of unprocessed material is achieved by heating it to a high temperature; the term generally applies to processing of organic material within the absence of air or within the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, like steam or phenols. it’s an application of pyrolysis. the method breaks up or ‘cracks’ large molecules. Coke, coal gas, gaseous carbon, coal tar, ammonia liquor, and kerosene are samples of commercial products historically produced by the fractionation of coal.