'Petrochemicals' are chemical products made from raw materials of
petroleum (
hydrocarbon) origin. (Etymologically, the name is incorrect, as the
Greek root ''petro-'' means "rock"; the correct term is ''oleochemicals'', from the Greek root ''oleo-'', meaning "oil".) Although some of the
chemical compounds which originate from petroleum may also be derived from other sources such as
coal or
natural gas, petroleum is a major source of many. This article is mainly intended to discuss
organic compounds or materials which are not burned as
fuel (see also
Petroleum product).
The two main classes of petrochemical raw materials are
olefins (including
ethylene and
propylene) and
aromatics (including
benzene and
xylene isomers), both of which are produced in very large quantities. At
oil refineries, olefins are produced mainly from hydrocarbons by chemical
cracking such as
steam cracking and by
catalytic reforming. At oil refineries, aromatic hydrocarbons are mainly produced by catalytic reforming or similar processes. From these basic building blocks are made a very wide range of
chemicals and other materials used in industry -
monomers,
solvents,
detergents,
adhesives, etc. From the monomers,
polymers or
oligomers are produced for
plastics,
resins,
fibers,
elastomers, certain
lubricants and gels.
World production of ethylene is around 110 million tonnes per annum, 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:
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ethylene - the simplest olefin; used as a ripening hormone, a monomer and a chemical feedstock
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polyethylenes -
polymerized ethylene
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ethanol - made by
hydration (
chemical reaction adding
water) of ethylene
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ethylene oxide - sometimes called oxirane; can be made by
oxidation of ethylene
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ethylene glycol - from hydration of ethylene oxide or oxidation of ethylene
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engine coolant - contains
ethylene glycol
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polyesters - any of several polymers with ester linkages in the backbone chain
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glycol ethers - from condensation of glycols
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ethoxylates
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vinyl acetate
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1,2-dichloroethane
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trichloroethylene
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tetrachloroethylene - also called perchloroethylene; used as a dry cleaning solvent and degreaser
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vinyl chloride - monomer for
polyvinyl chloride
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polyvinyl chloride (PVC) - type of plastic used for pipng, tubing, other things
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propylene - used as a monomer and a chemical feedstock
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isopropyl alcohol - 2-propanol; often used as a solvent or rubbing alcohol
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acrylonitrile - useful as a monomer in forming
Orlon,
ABS
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polypropylene -
polymerized propylene
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propylene oxide
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propylene glycol - sometimes used in engine coolant
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glycol ethers - from condensation of glycols
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isomers of butylene - useful as monomers or co-monomers
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★ isobutylene - feed for making
methyl ''tert''-butyl ether (MTBE) or monomer for copolymerization with a low percentage of
isoprene to make
butyl rubber
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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)
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synthetic rubbers - synthetic elastomers made of any one or more of several petrochemical (usually) monomers such as 1,3-butadiene, styrene, isobutylene, isoprene, chloroprene, etc. Elastomeric polymers are often made with a high percentage of conjugated diene monomers such as 1,3-butadiene, isoprene, or chloroprene.
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higher olefins
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polyolefins such poly-alpha-olefins which are used as lubricants
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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.
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detergent alcohols
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acrylic acid
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acrylic polymers
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allyl chloride -
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epichlorohydrin - chloro-oxirane; used in epoxy resin formation
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epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some
amine
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benzene - the simplest aromatic hydrocarbon
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ethylbenzene - made from benzene and ethylene
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styrene made by dehydrogenation of ethylbenzene; used as a monomer
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polystyrenes - polymers with styrene as a monomer
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cumene - isopropylbenzene; a feedstock in the
cumene process
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phenol - hydroxybenzene; often made by the cumene process
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acetone - dimethyl ketone; also often made by the cumene process
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bisphenol A - a type of "double" phenol used in polymerization in epoxy resins and making a common type of polycarbonate
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epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some
amine
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polycarbonate - a plastic polymer made from bisphenol A and
phosgene (carbonyl dichloride)
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solvents - liquids used for dissolving materials. Examples often made from petrochemicals include ethanol, isopropyl alcohol, acetone, benzene, toluene, xylenes.
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cyclohexane - a 6-carbon aliphatic cyclic hydrocarbon sometimes used as a non-polar solvent
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adipic acid - a 6-carbon di
carboxylic acid which can be a precursor used as a co-monomer together with a di
amine to form an alternating copolymer form of nylon.
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nylons - types of
polyamides, some are alternating copolymers formed from copolymerizing dicarboxylic acid or derivatives with diamines
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caprolactam - a 6-carbon cyclic
amide
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nylons - types of
polyamides, some are from polymerizing caprolactam
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nitrobenzene - can be made by single nitration of benzene
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aniline - aminobenzene
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methylene diphenyl diisocyanate (MDI) - used as a co-monomer with
diols or polyols to form polyurethanes or with di- or poly
amines to form
polyureas
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polyurethanes
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alkylbenzene - a general type of aromatic hydrocarbon which can be used as a presursor for a
sulfonate surfactant (detergent)
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detergents - often include
surfactants types such as alkylbenzenesulfonates and nonylphenol ethoxylates
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chlorobenzene
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toluene - methylbenzene; can be a solvent or precursor for other chemicals
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benzene
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toluene diisocyanate (TDI) - used as co-monomers with
diols or polyols to form polyurethanes or with di- or poly
amines to form
polyureas
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polyurethanes - a polymer formed from diisocyanates and diols or polyols
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benzoic acid - carboxybenzene
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caprolactam
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nylon
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mixed xylenes - any of three dimethylbenzene isomers, could be a solvent but more often precursor chemicals
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★ ''ortho''-
xylene - both
methyl groups can be oxidized to form (''ortho-'')phthalic acid
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phthalic anhydride
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★ ''para''-
xylene - both methyl groups can be oxidized to form terephthalic acid
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dimethyl terephthalate - can be copolymerized to form certain polyesters
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polyesters - although there can be many types,
polyethylene terephthalate is made from petrochemical products and is very widely used.
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terephthalic acid - often copolymerized to form
polyethylene terephthalate
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polyesters
See also
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Petroleum
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Petroleum products
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Organization of the Petroleum Exporting Countries
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Sipchem