Crude benzol is a product which is produced during carbonization of coking coal. Benzol (also called as benzole) is the name normally applied in the chemical industry to a mixture of hydrocarbons of the benzene series, in which benzene itself predominates, in association with certain of its homologues and various impurities. The term is not applied to any particular mixture or quality of the liquids. The recovery of benzol from the coke oven gas implies the removal of vapours of the benzene series, and their subsequent conversion by condensation into different liquid products. The CAS number of crude benzol is 65996-78-3.