petrochemical

petrochemical, any one of a large group of chemicals derived from a component of petroleum or natural gas. The cracking processes for manufacturing gasoline produce vast quantities of gaseous hydrocarbons. Originally considered waste products suitable only for use as illuminants and fuels, the gases today are manufactured into petrochemical substances widely employed in industry. Important petrochemical compounds are alcohols and aldehydes, butylene, butadiene, ethylene, propylene, toluene, styrene, acetylene, benzene, ethylene oxide, ethylene glycol, acrylonitrile, acetone, acetic acid, acetic anhydride, and ammonia. Materials made from the gases include carbon black, synthetic rubber, polystyrene, polypropylene, and polyethylene. Petrochemicals are widely used in agriculture, in the manufacture of plastics, synthetic fibers, and explosives, and in the aircraft and automobile industries.

Strictly, any of a large class of chemicals (as distinct from fuels) derived from petroleum and natural gas. The category has been broadened to include a much larger range of organic compounds and a few inorganic compounds (including carbon black, sulfur, and ammonia). Some materials cannot be classifed unequivocally because they have alternative sources (benzene from coal, ethanol from fermentation). Like crude oil and natural gas, most petrochemicals consist mainly of carbon and hydrogen and are called hydrocarbons. Petrochemicals used as raw materials (feedstocks) include ethylene, propylene, butadiene, benzene, toluene, xylene, and naphthalene. Among the myriad petrochemical products are plastics (e.g., polyethylene, polypropylene, polystyrene), soaps and detergents, solvents, drugs, fertilizers, pesticides, explosives, synthetic fibres and rubberss, paints, epoxies, flooring and insulating materials, luggage, and recording disks and tapes.

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Petrochemicals are chemical products made from raw materials of petroleum or other hydrocarbon origin. Although some of the chemical compounds that originate from petroleum may also be derived from World production of ethylene is around 110 million tonnes per year, of propylene 65 million tonnes, and of aromatic raw materials 70 million tonnes. The largest petrochemical industries are to be found in the USA and Western Europe, though the major growth in new production capacity is in the Middle East and Asia. There is a substantial inter-regional trade in petrochemicals of all kinds.

The following is a partial list of the major commercial petrochemicals and their derivatives:

• ethylene - the simplest olefin; used as a ripening hormone, a monomer and a chemical feedstock
• polyethylenes - polymerized ethylene
• ethanol - made by hydration (chemical reaction adding water) of ethylene
• ethylene oxide - sometimes called oxirane; can be made by oxidation of ethylene
• ethylene glycol - from hydration of ethylene oxide or oxidation of ethylene
• engine coolant - contains ethylene glycol
• polyesters - any of several polymers with ester linkages in the backbone chain
• glycol ethers - from condensation of glycols
• ethoxylates
• vinyl acetate
• 1,2-dichloroethane
• trichloroethylene
• tetrachloroethylene - also called perchloroethylene; used as a dry cleaning solvent and degreaser
• vinyl chloride - monomer for polyvinyl chloride
• polyvinyl chloride (PVC) - type of plastic used for piping, tubing, other things
• propylene - used as a monomer and a chemical feedstock
• isopropyl alcohol - 2-propanol; often used as a solvent or rubbing alcohol
• acrylonitrile - useful as a monomer in forming Orlon, ABS
• polypropylene - polymerized propylene
• propylene oxide
• propylene glycol - sometimes used in engine coolant
• glycol ethers - from condensation of glycols
• isomers of butylene - useful as monomers or co-monomers
• isobutylene - feed for making methyl tert-butyl ether (MTBE) or monomer for copolymerization with a low percentage of isoprene to make butyl rubber
• 1,3-butadiene - a diene often used as a monomer or co-monomer for polymerization to elastomers such as polybutadiene or a plastic such as acrylonitrile-butadiene-styrene (ABS)
• synthetic rubbers - synthetic elastomers made of any one or more of several petrochemical (usually) monomers such as 1,3-butadiene, styrene, isobutylene, isoprene, chloroprene; elastomeric polymers are often made with a high percentage of conjugated diene monomers such as 1,3-butadiene, isoprene, or chloroprene
• higher olefins
• polyolefins such poly-alpha-olefins which are used as lubricants
• alpha-olefins - used as monomers, co-monomers, and other chemical precursors. For example, a small amount of 1-hexene can be copolymerized with ethylene into a more flexible form of polyethylene.
• other higher olefins
• detergent alcohols
• acrylic acid
• acrylic polymers
• allyl chloride -
• epichlorohydrin - chloro-oxirane; used in epoxy resin formation
• epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some amine

• benzene - the simplest aromatic hydrocarbon
• ethylbenzene - made from benzene and ethylene
• styrene made by dehydrogenation of ethylbenzene; used as a monomer
• polystyrenes - polymers with styrene as a monomer
• cumene - isopropylbenzene; a feedstock in the cumene process
• phenol - hydroxybenzene; often made by the cumene process
• acetone - dimethyl ketone; also often made by the cumene process
• bisphenol A - a type of "double" phenol used in polymerization in epoxy resins and making a common type of polycarbonate
• epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some amine
• polycarbonate - a plastic polymer made from bisphenol A and phosgene (carbonyl dichloride)
• solvents - liquids used for dissolving materials; examples often made from petrochemicals include ethanol, isopropyl alcohol, acetone, benzene, toluene, xylenes
• cyclohexane - a 6-carbon aliphatic cyclic hydrocarbon sometimes used as a non-polar solvent
• adipic acid - a 6-carbon dicarboxylic acid which can be a precursor used as a co-monomer together with a diamine to form an alternating copolymer form of nylon.
• nylons - types of polyamides, some are alternating copolymers formed from copolymerizing dicarboxylic acid or derivatives with diamines
• caprolactam - a 6-carbon cyclic amide
• nylons - types of polyamides, some are from polymerizing caprolactam
• nitrobenzene - can be made by single nitration of benzene
• aniline - aminobenzene
• methylene diphenyl diisocyanate (MDI) - used as a co-monomer with diols or polyols to form polyurethanes or with di- or polyamines to form polyureas
• polyurethanes
• alkylbenzene - a general type of aromatic hydrocarbon which can be used as a presursor for a sulfonate surfactant (detergent)
• detergents - often include surfactants types such as alkylbenzenesulfonates and nonylphenol ethoxylates
• chlorobenzene
• toluene - methylbenzene; can be a solvent or precursor for other chemicals
• benzene
• toluene diisocyanate (TDI) - used as co-monomers with diols or polyols to form polyurethanes or with di- or polyamines to form polyureas
• polyurethanes - a polymer formed from diisocyanates and diols or polyols
• benzoic acid - carboxybenzene
• caprolactam
• nylon
• mixed xylenes - any of three dimethylbenzene isomers, could be a solvent but more often precursor chemicals
• ortho-xylene - both methyl groups can be oxidized to form (ortho-)phthalic acid
• phthalic anhydride
• para-xylene - both methyl groups can be oxidized to form terephthalic acid
• dimethyl terephthalate - can be copolymerized to form certain polyesters
• polyesters - although there can be many types, polyethylene terephthalate is made from petrochemical products and is very widely used.
• purified terephthalic acid - often copolymerized to form polyethylene terephthalate
• polyesters

See also

• Petroleum
• Petroleum products
• Organization of the Petroleum Exporting Countries

External links

• Petrochemistry in Europe
• Educational resource on petrochemistry
• Article showing some of the basics of a petchem facility