Editing Alkene (section)

===Industrial methods===
Alkenes are produced by hydrocarbon [[cracking (chemistry)|cracking]]. Raw materials are mostly [[natural-gas condensate]] components (principally ethane and propane) in the US and Mideast and [[naphtha]] in Europe and Asia. Alkanes are broken apart at high temperatures, often in the presence of a [[zeolite]] catalyst, to produce a mixture of primarily aliphatic alkenes and lower molecular weight alkanes. The mixture is feedstock and temperature dependent, and separated by fractional distillation. This is mainly used for the manufacture of small alkenes (up to six carbons).<ref name="Wade2">{{cite book | last = Wade | first = L.G. | title = Organic Chemistry | url = https://archive.org/details/organicchemistry00wade_388 | url-access = limited | publisher = Pearson [[Prentice Hall]] | date = 2006 |edition=6th| pages = [https://archive.org/details/organicchemistry00wade_388/page/n351 309] | isbn = 978-1-4058-5345-3 }}</ref>
[[Image:OctaneCracking.svg|500px|center|Cracking of ''n''-octane to give pentane and propene]]

Related to this is catalytic [[dehydrogenation]], where an alkane loses hydrogen at high temperatures to produce a corresponding alkene.<ref name="Wade"/> This is the reverse of the [[catalytic hydrogenation]] of alkenes.
[[Image:ButaneDehydrogenation.svg|600px|center|Dehydrogenation of butane to give butadiene and isomers of butene]]
This process is also known as [[Catalytic reforming|reforming]].  Both processes are endothermic and are driven towards the alkene at high temperatures by [[entropy]].

[[Catalytic]] synthesis of higher α-alkenes (of the type RCH=CH<sub>2</sub>) can also be achieved by a reaction of ethylene with the [[organometallic compound]] [[triethylaluminium]] in the presence of [[nickel]], [[cobalt]], or [[platinum]].