Crude Benzol
Crude benzol is a by-product obtained during the carbonization of coking coal in coke ovens. In the chemical industry, the term benzol (also referred to as benzole) generally applies to a mixture of aromatic hydrocarbons belonging to the benzene series, with benzene being the predominant component. This mixture also includes several of its homologues and minor impurities.
Unlike a fixed compound, crude benzol does not refer to a single, uniform liquid but rather to a range of condensates recovered from coke oven gas. The recovery process involves removing vapors of the benzene series from the gas stream and converting them into liquid hydrocarbons through condensation. The CAS number for crude benzol is 65996-78-3.
Production and Composition
Crude benzol is generated during the high-temperature carbonization of coal. Within coke oven gas, it typically occurs in concentrations of 25–40 grams per normal cubic meter (g/Nm³).
The mixture primarily contains hydrocarbons of the benzene series, an important class of aromatic hydrocarbons with the general formula CnH2n–6 (where n is 6 or more). Key examples include:
- Benzene (C6H6)
- Toluene (C7H8)
- Xylene (C8H10)
At standard conditions, these compounds are clear, colorless liquids with similar properties and high industrial significance. Additionally, crude benzol may contain small amounts of naphthalene (C10H8).
Industrial Importance
The benzene series hydrocarbons present in crude benzol are among the most valuable feedstocks in the chemical and petrochemical industries. They serve as raw materials for producing solvents, plastics, resins, synthetic fibers, and fuel additives. Due to their aromatic structure, they form the foundation for numerous industrial chemicals and commercial applications.
