Benzene is colorless and flammable liquid with a sweet and gasoline-like smell with chemical formula of C6H6. It is organic chemical compounds as a ring which is surrounded by 6 carbons atoms and six hydrogens atoms and known as a hydrocarbon. Benzole, mineral naphta, phenyl hydrid and annulene(6) are another names of this compounds.
Benzene has different physical and chemical properties. Its molar mass is 78.11 g/mole with density of 0.87 g/cm3.
There are different sources for benzene but it is mainly found in crude oil and it is major part of gasoline. Moreover, it is produced in the earth atmosphere and is observed in the air due to burning of coal and oil emission, gas station and motor vehicles exhaust. Although, industrial methods for manufacturer of benzene involved various chemical process. Given below are some of them.
- Catalytic reforming
In this process, mixture of hydrocarbons with boiling point in range of 60-200 is mixture with hydrogen gas and followed by chloride catalysts under heating and high pressure. At the final step, benzene will be separated from other aromatics through filtration. This is so much effective process for production of aromatics.
- Toluene hydrodealkylation
This process is involved conversion of toluene to benzene. At the first step, toluene is mixed with hydrogen and passes through oxides catalysts under high temperature and high pressure.
- Toluene disproportionation
In this process, two toluene molecule react with each other and 1 molecule xylene and 1 molecules benzene will be produce.
- Steam cracking
This process includes production of ethylene and other alkenes from aliphatic hydrocarbons. Pyrolysis gasoline is the main step in this process which ended up to make olefins and benzene-rich liquid as by product.
- Reduction of phenols and halobenzene by metals
- Decarboxylation of benzoic acid to benzene
- Reaction of diozonium compounds by hypophosphorous acid aniline
- Trimerization of acetylene
Application of Benzene
The main usage of benzene is to act as a precursor to produce of chemicals with more complex structure. Also, it is mostly used industrial chemical. Given below are some of its uses.
- To make plastics, resin, synthetic fibers, textiles and nylon fibers
- Produce of styrene to make different polymers and plastics like polystyrene and EPS
- To make rubbers, lubricants, dyes, detergents, pesticide
- To synthesize drugs, glues, adhesives, cleaning products, paint strippers
- To manufacturer tobacco smoke and gasoline
- Intermediate to make other chemicals like, ethylbenzene, cumene, cyclohexane, nitrobenzene, and alkylbenzene.
- To produce cyclohexane, toluene, phenol and acetone for resins and adhesives
- To make explosives
- As a fuel additive
Chemical reactions of benzene:
The most common reaction which benzene can involve are substitution of protons with other groups. Sulfonation, chlorination, nitration, hydrogenation and metal complex are others chemical process including benzene.
Handling, Health effect and Toxicity:
Nowadays, people extremely are exposed the benzene through, filling their car with gasoline, using household products, so it is classified as a carcinogen. There are several ways to reduce its hazards, namely, stop breathing its vapors, storing gasoline in stable containers, stop handling gasoline in homes, filling container of gasoline under ventilation.
Exposure may happen through inhalation from wood smoke, tobacco smoke, automobile service stations, soft drinks, contamination of water supply, and skin contact.
Therefore, the risk of cancer and other illness increase gradually during modern capitalism. Benzene can lead to some hematological malignancy, such as acute myeloid leukemia, aplastic anemia, myelodysplastics syndrome, acute lymphoblastic leukemia, and chronic myloid leukemia.