Editing Ethylene (section)

==Uses==
[[File:Uses_of_Ethene.tif|thumb|left|Diagram of uses of ethene]]
Major industrial reactions of ethylene include in order of scale: 1) [[polymerization]], 2) [[oxidation]], 3) [[halogenation]] and [[hydrohalogenation]], 4) [[alkylation]], 5) [[Hydration reaction|hydration]], 6) [[oligomerization]], and 7) [[hydroformylation]]. In the [[United States]] and [[Europe]], approximately 90% of ethylene is used to produce [[ethylene oxide]], [[ethylene dichloride]], [[ethylbenzene]] and [[polyethylene]].<ref name="inchem">{{cite web |url=http://www.inchem.org/documents/sids/sids/74851.pdf |title=OECD SIDS Initial Assessment Profile — Ethylene |publisher=inchem.org |access-date=2008-05-21 |archive-url=https://web.archive.org/web/20150924051942/http://www.inchem.org/documents/sids/sids/74851.pdf |archive-date=2015-09-24 |url-status=dead}}</ref> Most of the reactions with ethylene are [[electrophilic addition]].{{Citation needed|date=January 2021}}

[[Image:C2H4uses.png|thumb|520 px|left|Main industrial uses of ethylene. Clockwise from the upper right: its conversions to [[ethylene oxide]], precursor to [[ethylene glycol]]; to [[ethylbenzene]], precursor to [[styrene]]; to various kinds of [[polyethylene]]; to [[ethylene dichloride]], precursor to [[vinyl chloride]].]]
{{clear|left}}

===Polymerization===
{{See also|Ziegler–Natta catalyst|Polyethylene}}
Polyethylene production uses more than half of the world's ethylene supply. Polyethylene, also called ''polyethene'' and ''polythene'', is the world's most widely used plastic. It is primarily used to make films in [[packaging]], [[carrier bags]] and trash [[bin bag|liners]]. Linear [[alpha-olefins]], produced by [[oligomerization]] (formation of short-chain molecules) are used as [[precursor (chemistry)|precursors]], [[detergents]], [[plasticisers]], [[synthetic lubricants]], additives, and also as co-monomers in the production of polyethylenes.<ref name="inchem" />

===Oxidation===
Ethylene is [[oxidation|oxidized]] to produce [[ethylene oxide]], a key raw material in the production of [[surfactant]]s and [[detergent]]s by [[ethoxylation]]. Ethylene oxide is also hydrolyzed to produce [[ethylene glycol]], widely used as an automotive antifreeze as well as higher molecular weight glycols, [[glycol ethers]], and [[polyethylene terephthalate]].<ref>{{Cite web|title=Ethylene Glycol: Systemic Agent|url=https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750031.html|website=Center for Disease Control|date=20 October 2021|access-date=20 February 2022|archive-date=26 December 2017|archive-url=https://web.archive.org/web/20171226021019/https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750031.html|url-status=live}}</ref><ref>{{Cite web|title=Ethylene Glycol|url=https://www.sciencedirect.com/topics/engineering/ethylene-glycol|website=Science Direct|access-date=2022-02-20|archive-date=2022-02-20|archive-url=https://web.archive.org/web/20220220235304/https://www.sciencedirect.com/topics/engineering/ethylene-glycol|url-status=live}}</ref>

{{Main|Wacker process}}
Ethylene oxidation in the presence of a  palladium catalyst can form [[acetaldehyde]]. This conversion remains a major industrial process (10M kg/y).<ref>{{cite book |vauthors=Elschenbroich C, Salzer A |title=Organometallics: A Concise Introduction |edition=2nd |publisher=Wiley-VCH |location=Weinheim |year=2006 |isbn=978-3-527-28165-7 }}</ref> The process proceeds via the initial complexation of ethylene to a Pd(II) center.{{Citation needed|date=January 2021}}

===Halogenation and hydrohalogenation===
Major intermediates from the [[halogenation]] and [[hydrohalogenation]] of ethylene include [[ethylene dichloride]], [[ethyl chloride]], and [[ethylene dibromide]]. The addition of chlorine entails "[[oxychlorination]]", i.e. chlorine itself is not used. Some products derived from this group are [[polyvinyl chloride]], [[trichloroethylene]], [[perchloroethylene]], [[methyl chloroform]], [[polyvinylidene chloride]] and [[copolymer]]s, and [[ethyl bromide]].<ref name=Keystone/>

===Alkylation===
Major chemical intermediates from the [[alkylation]] with ethylene is [[ethylbenzene]], precursor to [[styrene]]. Styrene is used principally in [[polystyrene]] for packaging and insulation, as well as in [[styrene-butadiene]] rubber for tires and footwear. On a smaller scale, [[ethyltoluene]], ethylanilines, 1,4-hexadiene, and [[aluminium]] alkyls. Products of these intermediates include [[polystyrene]], [[Saturated and unsaturated compounds|unsaturated]] [[polyester]]s and ethylene-propylene [[copolymer|terpolymers]].<ref name=Keystone/>

===Oxo reaction===
The [[hydroformylation]] (oxo reaction) of ethylene results in [[propionaldehyde]], a precursor to [[propionic acid]] and [[n-propyl alcohol]].<ref name=Keystone/>

===Hydration===
Ethylene has long represented the major nonfermentative precursor to [[ethanol]]. The original method entailed its conversion to [[diethyl sulfate]], followed by hydrolysis. The main method practiced since the mid-1990s is the direct hydration of ethylene catalyzed by [[solid acid catalyst]]s:<ref>{{cite book |vauthors=Kosaric N, Duvnjak Z, Farkas A, Sahm H, Bringer-Meyer S, Goebel O, Mayer D |chapter=Ethanol |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2011 |pages=1–72 |publisher=Wiley-VCH |location=Weinheim |doi=10.1002/14356007.a09_587.pub2 |isbn=9783527306732}}</ref>
:C<sub>2</sub>H<sub>4</sub>  +  H<sub>2</sub>O  →    CH<sub>3</sub>CH<sub>2</sub>OH

===Dimerization to butenes===
Ethylene is [[dimer (chemistry)|dimerized]] by [[hydrovinylation]] to give ''n''-butenes using processes licensed by Lummus or [[French Institute of Petroleum|IFP]]. The Lummus process produces mixed ''n''-butenes (primarily [[2-butene]]s) while the IFP process produces [[1-butene]]. 1-Butene is used as a [[comonomer]] in the production of certain kinds of [[polyethylene]].<ref>{{Cite web|title=1-Butene - Major Uses |url=https://webwiser.nlm.nih.gov/substance?substanceId=474&identifier=1-Butene&identifierType=name&menuItemId=22&catId=24|access-date=2021-11-16|website=WISER |language=en |url-status=dead |archive-url=https://web.archive.org/web/20211116165807/https://webwiser.nlm.nih.gov/substance?substanceId=474&identifier=1-Butene&identifierType=name&menuItemId=22&catId=24 |archive-date= Nov 16, 2021 }}</ref>

===Fruit and flowering===
{{main|Ethylene (plant hormone)}}
Ethylene is a hormone that affects the ripening and flowering of many plants.  It is widely used to control freshness in [[horticulture]] and [[fruit]]s.<ref>{{Cite book|last1=Arshad|first1=Muhammad|title=Ethylene|last2=Frankenberger|first2=William |url=https://books.google.com/books?id=7U-4TU0ryoAC&pg=PA289 |publisher=Springer|year=2002|isbn=978-0-306-46666-3|location=Boston, MA|pages=289}}</ref>  The scrubbing of naturally occurring ethylene delays ripening.<ref>{{Cite book |last1=Melton |first1=Laurence |first2=Fereidoon |last2=Shahidi |first3=Peter |last3=Varelis |title=Encyclopedia of Food Chemistry |url=https://books.google.com/books?id=MTV8DwAAQBAJ&pg=PA114 |publisher=Elsevier |year=2019 |isbn=978-0-12-814045-1 |location=Netherlands |pages=114}}</ref> Adsorption of ethylene by nets coated in [[titanium dioxide]] gel has also been shown to be effective.<ref>{{cite journal | title = Gelatin-TiO2-coated expanded polyethylene foam nets as ethylene scavengers for fruit postharvest application | first1 = J. | last1 = de Matos Fonseca | first2 = N.Y.L | last2 = Pabón | first3 = L.G | last3 = Nandi | journal = Postharvest Biology and Technology | date = 2021 | volume = 180 | doi = 10.1016/j.postharvbio.2021.111602}}</ref>

===Niche uses===
An example of a niche use is as an [[anesthesiology|anesthetic agent]] (in an 85% ethylene/15% oxygen ratio).<ref>{{cite journal |vauthors=Trout HH |title=Blood Changes Under Ethylene Anæsthesia |journal=Annals of Surgery |volume=86 |issue=2 |pages=260–7 |date=August 1927 |pmid=17865725 |pmc=1399426 |doi=10.1097/00000658-192708000-00013}}</ref> It is also used as a refrigerant gas for low temperature applications under the name R-1150.<ref>{{Cite web |date=April 2015 |title=R-1150 ETHYLENE Safety Data Sheet |url=https://www.arma.org.au/wp-content/uploads/2017/02/SDS-R1150-Ethylene.pdf |access-date=1 July 2023 |website=Australian Refrigeration Mechanics Association |archive-date=1 July 2023 |archive-url=https://web.archive.org/web/20230701104846/https://www.arma.org.au/wp-content/uploads/2017/02/SDS-R1150-Ethylene.pdf |url-status=live }}</ref>