View source for Methanol

{{short description|CH3OH; simplest possible alcohol}}
{{Distinguish|menthol|methanal|menthone|Dimepheptanol{{!}}methadol|Oxymetholone{{!}}methabol|ethanol}}
{{Use dmy dates|date=August 2024}}

{{Chembox
|Verifiedfields = changed
|Watchedfields = changed
|verifiedrevid = 409752739
|ImageFileL1 = 
|ImageNameL1 = Skeletal formula of methanol with some explicit hydrogens added
|ImageFileR1 = Methanol-3D-vdW.png
|ImageNameR1 = Spacefill model of methanol
|ImageFileL2 = Methanol-2D.svg
|ImageClassL2 = skin-invert-image
|ImageNameL2 = [[Space filling model]] of methanol
|ImageFileR2 = Methanol-3D-balls.png
|ImageClassR2 = bg-transparent
|ImageNameR2 = [[Ball and stick model]] of methanol
|ImageFile3 = Methanol by Danny S. - 001.JPG
|ImageName3 = A sample of methanol
|PIN = Methanol<ref name=iupac2013>{{cite book | title =Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The [[Royal Society of Chemistry]] | date = 2014 | location = Cambridge | page = 692 | doi = 10.1039/9781849733069-00648 | isbn = 978-0-85404-182-4}}</ref>
|OtherNames = Carbinol<br />Columbian spirits<br/> Hydroxymethane<br />MeOH<br />Methyl alcohol<br />Methyl hydrate<br />Methyl hydroxide<br />Methylic alcohol<br />Methylol<br />Methylene hydrate, primary alcohol<br />Pyroligneous spirit<br/>Wood alcohol<br/>Wood naphtha<br/>Wood spirit
|Section1 = {{Chembox Identifiers
|CASNo = 67-56-1
|CASNo_Ref = {{cascite|correct|CAS}}
|PubChem = 887
|ChemSpiderID = 864
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|UNII = Y4S76JWI15
|UNII_Ref = {{fdacite|correct|FDA}}
|EINECS = 200-659-6
|UNNumber = 1230
|KEGG = D02309
|KEGG_Ref = {{keggcite|correct|kegg}}
|MeSHName = Methanol
|ChEBI_Ref = {{ebicite|correct|EBI}}
|ChEBI = 17790
|ChEMBL = 14688
|ChEMBL_Ref = {{ebicite|correct|EBI}}
|RTECS = PC1400000
|Beilstein = 1098229
|Gmelin = 449
|3DMet = B01170
|SMILES = CO
|StdInChI = 1S/CH4O/c1-2/h2H,1H3
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|InChI = 1/CH4O/c1-2/h2H,1H3
|StdInChIKey = OKKJLVBELUTLKV-UHFFFAOYSA-N
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|InChIKey = OKKJLVBELUTLKV-UHFFFAOYAX
}}
|Section2 = {{Chembox Properties
|Formula = {{chem2|CH3OH}}
|C=1|H=4|O=1
|Appearance = Colourless liquid
|Odor = Faint and similar to ethanol
|Density = 0.792 g/cm<sup>3</sup><ref>{{RubberBible86th}}</ref>
|BoilingPtC = 64.7
|MeltingPtC = −97.6
|Solubility = [[Miscibility|miscible]]
|RefractIndex = 1.33141<ref>{{Cite web|url=http://refractiveindex.info/?group=LIQUIDS&material=Methanol|title=RefractiveIndex.INFO – Refractive index database|website=refractiveindex.info|access-date=14 February 2012|archive-date=23 February 2017|archive-url=https://web.archive.org/web/20170223045254/https://refractiveindex.info/?group=LIQUIDS&material=Methanol|url-status=live}}</ref>
|VaporPressure = 13.02 kPa (at 20&nbsp;°C)
|LogP = −0.69
|pKa = 15.5<ref>{{cite journal | last1 = Ballinger | first1 = P. | last2 = Long | first2 = F. A. | year = 1960 | title =Acid Ionization Constants of Alcohols. II. Acidities of Some Substituted Methanols and Related Compounds | journal = J. Am. Chem. Soc. | volume = 82 | issue = 4 | pages = 795–798 | doi = 10.1021/ja01489a008| bibcode = 1960JAChS..82..795B }}</ref>
|ConjugateAcid = Methyloxonium<ref>{{cite web |title=Methyloxonium |url=https://pubchem.ncbi.nlm.nih.gov/compound/12660727 |website=pubchem.ncbi.nlm.nih.gov |access-date=21 December 2018 |archive-date=21 December 2018 |archive-url=https://web.archive.org/web/20181221134635/https://pubchem.ncbi.nlm.nih.gov/compound/12660727 |url-status=live}}</ref>
|ConjugateBase = [[Methoxide#Methoxide ion|Methanolate]]<ref>{{cite web |title=Methanolate |url=https://pubchem.ncbi.nlm.nih.gov/compound/3826051#section=Top |website=pubchem.ncbi.nlm.nih.gov |access-date=21 December 2018 |quote=Methoxide is an organic anion that is the conjugate base of methanol. ... It is a conjugate base of a methanol. |archive-date=21 December 2018 |archive-url=https://web.archive.org/web/20181221134641/https://pubchem.ncbi.nlm.nih.gov/compound/3826051#section=Top |url-status=live}}</ref>
|Viscosity = 0.545 mPa·s (at 25&nbsp;°C)<ref>{{cite journal | last1 = González | first1 = Begoña | year = 2007 | title = Density, dynamic viscosity, and derived properties of binary mixtures of methanol or ethanol with water, ethyl acetate, and methyl acetate at ''T'' = (293.15, 298.15, and 303.15) K | journal = The Journal of Chemical Thermodynamics | volume = 39 | issue = 12 | pages = 1578–1588 | doi = 10.1016/j.jct.2007.05.004| bibcode = 2007JChTh..39.1578G }}</ref>
|Dipole = 1.69 D
|MagSus = −21.40·10<sup>−6</sup> cm<sup>3</sup>/mol
}}
|Section3 = {{Chembox Thermochemistry
|HHV =725.7 kJ/mol, 173.4 kcal/mol, 5.77 kcal/g
}}
|Section4 = {{Chembox Hazards
|ExternalSDS = [https://www.biomcn.eu/wp-content/uploads/2014/03/SDS-methanol-20160901.pdf] 
|Hazards_ref = <ref name= CDC_card>{{cite web|url=https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750029.html#er|title=The Emergency Response Safety and Health Database: Systematic Agent: METHANOL|publisher=Centers for Disease Control and Prevention|access-date=3 August 2018|archive-date=23 April 2009|archive-url=https://web.archive.org/web/20090423005724/http://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750029.html#er|url-status=live}}</ref><ref name= PubChem>{{cite web|url=https://pubchem.ncbi.nlm.nih.gov/compound/887#section=Safety-and-Hazards|title=PubChem: Safety and Hazards - GHS Classification|publisher=National Center for Biotechnology Information, U.S. National Library of Medicine|access-date=20 August 2018|archive-date=20 August 2018|archive-url=https://web.archive.org/web/20180820140939/https://pubchem.ncbi.nlm.nih.gov/compound/887#section=Safety-and-Hazards|url-status=live}}</ref>
|GHSPictograms = {{GHS flame}}{{GHS skull and crossbones}}{{GHS health hazard}}<ref name=labchem>{{cite web|title=Methanol|url=http://www.labchem.com/tools/msds/msds/VT430.pdf|website=Lab Chem|publisher=Valtech|access-date=10 March 2016|archive-date=10 March 2016|archive-url=https://web.archive.org/web/20160310201322/http://www.labchem.com/tools/msds/msds/VT430.pdf|url-status=live}}</ref>
|GHSSignalWord = Danger<ref name=labchem/>
|HPhrases = {{H-phrases|225|301|302|305|311|331|370}}<ref name=labchem/>
|PPhrases = {{P-phrases|210|233|240|241|242|243|260|264|270|271|280|301+330+331|310|302+352|312|303+361+353|304+340|311|305+351+338|307+311|337+313|361|363|370+378|403+233|235|405|501}}<ref name=labchem/>
|MainHazards = Methanol and its vapours are flammable.
Moderately [[toxic]] for small animals – Highly toxic to large animals and humans (in high concentrations) – May be fatal/[[Lethality|lethal]] or cause [[Visual impairment|blindness]] and damage to the [[liver]], [[kidney]]s, and [[heart]] if swallowed – [[Toxicity]] effects from repeated over exposure have an accumulative effect on the [[central nervous system]], especially the [[optic nerve]] – [[Symptom]]s may be delayed, become severe after 12 to 18 hours, and linger for several days after exposure<ref name=":1">Toxicity on [https://pubchem.ncbi.nlm.nih.gov/compound/887#section=Toxicity <nowiki>PubChem</nowiki>] {{Webarchive|url=https://web.archive.org/web/20180820140939/https://pubchem.ncbi.nlm.nih.gov/compound/887#section=Toxicity |date=20 August 2018}}</ref>
|NFPA-H = 1<!--https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750029.html Do not change, discuss on the talk page first-->
|NFPA-F = 3
|NFPA-R = 0
|NFPA_ref = <ref name= CDC_card/><ref name= Methanol_Institute_253>{{cite web |url= http://www.methanol.org/wp-content/uploads/2017/03/Safe-Handling-Manual.pdf |title= Methanol Safe Handling Manual |website= [[Methanol Institute]] |date= 2017 |page= 253 |access-date= 3 August 2018 |archive-date= 20 December 2017 |archive-url= https://web.archive.org/web/20171220023201/http://www.methanol.org/wp-content/uploads/2017/03/Safe-Handling-Manual.pdf |url-status= live}}</ref>
|FlashPtC = 11 to 12
|AutoignitionPtC = 470
|AutoignitionPt_ref = <ref>{{cite web|url=http://www.methanol.org/Health-And-Safety/Safety-Resources/Health---Safety/Methanex-TISH-Guide.aspx |archive-url=https://web.archive.org/web/20120311081112/http://www.methanol.org/Health-And-Safety/Safety-Resources/Health---Safety/Methanex-TISH-Guide.aspx |archive-date=11 March 2012 |title=Technical Information & Safe Handling Guide for Methanol |publisher= [[Methanex]] Corporation}}</ref><br />
{{convert|385|C|F K}}<ref name= Methanol_Institute>{{cite web |url= http://www.methanol.org/wp-content/uploads/2017/03/Safe-Handling-Manual.pdf |title= Methanol Safe Handling Manual |website= [[Methanol Institute]] |date= 2017 |page= 243 |access-date= 3 August 2018 |archive-date= 20 December 2017 |archive-url= https://web.archive.org/web/20171220023201/http://www.methanol.org/wp-content/uploads/2017/03/Safe-Handling-Manual.pdf |url-status= live}}</ref>
|ExploLimits = 6–36%<ref name=PGCH/>
|PEL = TWA 200 ppm (260 mg/m<sup>3</sup>)<ref name=PGCH>{{PGCH|0397}}</ref>
|IDLH = 6000 ppm<ref name=PGCH/>
|LC50 = 64,000 ppm (rat, 4&nbsp;h)<ref name=IDLH>{{IDLH|67561|Methanol}}</ref>
|LD50 = 5628 mg/kg (rat, oral)<br/>7300 mg/kg (mouse, oral)<br/>12880 mg/kg (rat, oral)<br/>14200 mg/kg (rabbit, oral)<ref name=IDLH/>
|REL = TWA 200 ppm (260 mg/m<sup>3</sup>) ST 250 ppm (325 mg/m<sup>3</sup>) [skin]<ref name=PGCH/>
|LCLo = 33,082 ppm (cat, 6&nbsp;h)<br/>37,594 ppm (mouse, 2&nbsp;h)<ref name=IDLH/>
}}
|Section5 = {{Chembox Related
|OtherCompounds = [[Methanethiol]]<br />[[Silanol]]<br />[[Ethanol]]
}}
}}

'''Methanol''' (also called '''methyl alcohol''', '''wood alcohol''', and '''wood spirit''', amongst other names) is an organic [[chemical compound]] and the simplest [[aliphatic]] [[Alcohol (chemistry)|alcohol]], with the [[chemical formula]] {{chem2|CH3OH|auto=1}} (a [[methyl group]] linked to a [[hydroxyl group]], often abbreviated as '''MeOH'''). It is a light, [[Volatility (chemistry)|volatile]], colorless and [[flammable]] liquid with a distinctive alcoholic odor similar to that of [[ethanol]] (potable alcohol), but is more acutely toxic than the latter.<ref name="ershdb">{{cite web
| last = National Institute for Occupational Safety and Health
| title = The Emergency Response Safety and Health Database: Methanol
| date = 22 August 2008
| url = https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750029.html
| access-date = 17 March 2009
| archive-date = 23 April 2009
| archive-url = https://web.archive.org/web/20090423005724/http://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750029.html
| url-status = live
}}</ref>
Methanol acquired the name '''wood alcohol''' because it was once produced through [[destructive distillation]] of [[wood]]. Today, methanol is mainly produced industrially by [[hydrogenation]] of [[carbon monoxide]].<ref name=Ullmann/> 

Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a [[Precursor (chemistry)|precursor]] to other [[commodity chemicals]], including [[formaldehyde]], [[acetic acid]], [[methyl tert-butyl ether|methyl ''tert''-butyl ether]], [[methyl benzoate]], [[anisole]], [[peroxyacid]]s, as well as a host of more specialized chemicals.<ref name=Ullmann/>

{{TOC limit|3}}

==Occurrence==
Small amounts of methanol are present in normal, healthy human individuals. One study found a mean of 4.5&nbsp;[[parts per million|ppm]] in the exhaled breath of test subjects.<ref>{{Cite journal|last1=Turner C|title=A longitudinal study of methanol in the exhaled breath of 30 healthy volunteers using selected ion flow tube mass spectrometry, SIFT-MS|journal=Physiological Measurement|volume=27|issue=7|pages=637–48|pmid=16705261|year=2006|doi=10.1088/0967-3334/27/7/007|bibcode=2006PhyM...27..637T|s2cid=22365066}}</ref> The mean endogenous methanol in humans of 0.45 g/d may be metabolized from [[pectin]] found in fruit; one kilogram of apple produces up to 1.4 g of pectin (0.6 g of methanol.)<ref>{{Cite journal|last1=Lindinger W|title=Endogenous production of methanol after the consumption of fruit|journal=Alcoholism: Clinical and Experimental Research|volume=21|issue=5|pages=939–43|pmid=9267548|year=1997|doi=10.1111/j.1530-0277.1997.tb03862.x}}</ref>

Methanol is produced by [[anaerobic organism|anaerobic bacteria]] and [[phytoplankton]].<ref>{{Cite web| url=http://www.whoi.edu/news-release/major-source-of-methanol-in-the-ocean-identified| title=Major Source of Methanol in the Ocean Identified| website=Woods Hole Oceanographic Institution| access-date=30 March 2016| date=10 March 2016| archive-date=28 December 2018| archive-url=https://web.archive.org/web/20181228012937/http://www.whoi.edu/news-release/major-source-of-methanol-in-the-ocean-identified| url-status=live}}</ref><ref>{{Cite journal| last1=Mincer| first1=Tracy J.| last2=Aicher| first2=Athena C.| title=Methanol Production by a Broad Phylogenetic Array of Marine Phytoplankton| journal=PLOS ONE| volume=11| issue=3| doi=10.1371/journal.pone.0150820| pmc=4786210| pmid=26963515| article-number=e0150820| year=2016| bibcode=2016PLoSO..1150820M| doi-access=free}}</ref>

===Interstellar medium===
Methanol is also found in abundant quantities in star-forming regions of space and is used in astronomy as a marker for such regions. It is detected through its spectral emission lines.<ref>{{cite news |url= http://www.spacedaily.com/reports/Why_astronomers_hate_the_lawn-mowing_Roomba_999.html |title= Why astronomers hate the lawn-mowing Roomba |publisher= Space Daily |date= 17 April 2015 |author= Brooks Hays |access-date= 20 April 2015 |archive-date= 27 April 2015 |archive-url= https://web.archive.org/web/20150427143024/http://www.spacedaily.com/reports/Why_astronomers_hate_the_lawn-mowing_Roomba_999.html |url-status= live}}</ref>

In 2006, astronomers using the [[MERLIN]] array of radio telescopes at [[Jodrell Bank|Jodrell Bank Observatory]] discovered a large cloud of methanol in space {{convert|288|e6mi|Tm|lk=in|abbr=off|order=flip}} across.<ref>{{cite press release | url = http://www.jodrellbank.manchester.ac.uk/news/2006/cloud/ | publisher = [[Jodrell Bank Centre for Astrophysics]] | title = Upgraded MERLIN spies cloud of alcohol spanning 288 billion miles | date = 19 April 2006 | archive-url = https://web.archive.org/web/20110720152236/http://www.jodrellbank.manchester.ac.uk/news/2006/cloud/ | archive-date = 20 July 2011}}</ref><ref>{{cite news | work = BBC News | url = https://news.bbc.co.uk/2/hi/science/nature/4878048.stm | title = Merlin sees vast alcohol stream | author = Amos, Jonathan | date = 5 April 2006 | access-date = 5 September 2010 | archive-date = 6 October 2014 | archive-url = https://web.archive.org/web/20141006215342/http://news.bbc.co.uk/2/hi/science/nature/4878048.stm | url-status = live}}</ref> In 2016, astronomers detected methanol in a planet-forming disc around the young star [[TW Hydrae]] using the [[Atacama Large Millimeter Array]] radio telescope.<ref>{{cite web|title=First Detection of Methyl Alcohol in a Planet-forming Disc|url=http://www.eso.org/public/news/eso1619/|access-date=22 June 2016|archive-date=22 June 2016|archive-url=https://web.archive.org/web/20160622153217/http://www.eso.org/public/news/eso1619/|url-status=live}}</ref>

==History==<!-- This section is linked from [[Methyl group]] -->
In their [[embalming]] process, the [[ancient Egyptians]] used a mixture of substances, including methanol, which they obtained from the [[pyrolysis]] of wood. Pure methanol, however, was first isolated in 1661 by [[Robert Boyle]], when he produced it via the distillation of [[buxus]] (boxwood).<ref>Boyle discusses the distillation of liquids from the wood of the box shrub in: Robert Boyle, ''The Sceptical Chymist'' (London, England: J. Cadwell, 1661), [https://archive.org/stream/scepticalchymis00BoylA#page/192/mode/2up/ pp. 192–195].</ref> It later became known as "pyroxylic spirit". In 1834, the French chemists [[Jean-Baptiste Dumas]] and [[Eugene Peligot]] determined its elemental composition.<ref name=Dumas>A report on methanol to the French Academy of Sciences by J. Dumas and E. Péligot began during the Academy's meeting of 27 October 1834 and finished during the meeting of 3 November 1834. See: ''Procès-verbaux des séances de l'Académie'', '''10''' : 600–601. Available on: [http://gallica.bnf.fr/ark:/12148/bpt6k33037/f606.image Gallica] {{Webarchive|url=https://web.archive.org/web/20150425033225/http://gallica.bnf.fr/ark:/12148/bpt6k33037/f606.image |date=25 April 2015}}. The complete report appears in: J. Dumas and E. Péligot (1835) [{{google books |plainurl=y |id=xSs8oDQV4uYC&|page=44}} "Mémoire sur l'espirit de bois et sur les divers composés ethérés qui en proviennent"] (Memoir on spirit of wood and on the various ethereal compounds that derive therefrom), ''Annales de chimie et de physique'', '''58''' : 5–74; from [{{google books |plainurl=y |id=94c5AAAAcAAJ|page=9}} page 9]: ''Nous donnerons le nom de ''méthylène'' (1) à un radical ... (1) Μεθυ, vin, et υλη, bois; c'est-à-dire vin ou liqueur spiritueuse du bois.'' (We will give the name methylene (1) to a radical ... (1) ''methy'', wine, and ''hulē'', wood; that is, wine or spirit of wood.)</ref>

They also introduced the word "methylène" to organic chemistry, forming it from [[Greek language|Greek]] ''[[wiktionary:μέθυ#Ancient Greek|methy]]'' = "alcoholic liquid" + ''[[wiktionary:ὕλη#Ancient Greek|hȳlē]]'' = "forest, wood, timber, material". "Methylène" designated a [[Radical theory|"radical"]] that was about 14% hydrogen by weight and contained one carbon atom. This would be {{chem2|CH2}}, but at the time carbon was thought to have an [[atomic weight]] only six times that of hydrogen, so they gave the formula as CH.<ref name=Dumas/> They then called wood alcohol (l'esprit de bois) "bihydrate de méthylène" (bihydrate because they thought the formula was {{chem2|C4H8O4}} or {{chem2|(CH)4(H2O)2}}). The term "methyl" was derived in about 1840 by [[back-formation]] from "methylene", and was then applied to describe "methyl alcohol". This was shortened to "methanol" in 1892 by the [[IUPAC nomenclature|International Conference on Chemical Nomenclature]].<ref>For a report on the International Conference on Chemical Nomenclature that was held in April 1892 in Geneva, Switzerland, see:
* {{cite journal|doi=10.1038/046056c0|url={{google books |plainurl=y |id=LHkCAAAAIAAJ|page=5}}|title=The International Conference on Chemical Nomenclature|journal=Nature|volume=46|issue=1177|pages=56–9|last=Armstrong|first= Henry E|year=1892|bibcode=1892Natur..46...56A|doi-access=free}}
* Armstrong's report is reprinted with the resolutions in English in: {{cite journal|author= Armstrong, Henry |year=1892|url={{google books |plainurl=y |id=RogMAQAAIAAJ|page=398}}|title=The International Conference on Chemical Nomenclature|journal=The Journal of Analytical and Applied Chemistry|volume=6|issue=1177|pages=390–400|quote=p. 398: 15. The alcohols and the phenols are named after the hydrocarbon from which they derive, terminated with the suffix ''ol'' (ex. pentanol, pentenol, etc.). |bibcode=1892Natur..46...56A|doi=10.1038/046056c0|doi-access=free}}</ref> The [[suffix (linguistics)|suffix]] [[-yl]], which, in [[organic chemistry]], forms names of [[carbon]] groups, is from the word ''methyl''.

French chemist [[Paul Sabatier (chemist)|Paul Sabatier]] presented the first [[Sabatier reaction|process]] that could be used to produce methanol synthetically in 1905. This process suggested that carbon dioxide and hydrogen could be reacted to produce methanol.<ref name=":1" /> German chemists [[Alwin Mittasch]] and Mathias Pier, working for [[BASF|Badische-Anilin & Soda-Fabrik]] (BASF), developed a means to convert [[syngas|synthesis gas]] (a mixture of [[carbon monoxide]], [[carbon dioxide]], and [[hydrogen]]) into methanol and received a patent. According to Bozzano and Manenti, BASF's process was first utilized in [[Leuna]], Germany in 1923. Operating conditions consisted of "high" temperatures (between 300 and 400&nbsp;°C) and pressures (between 250 and 350 atm) with a [[zinc oxide|zinc]]/[[chromium(III) oxide|chromium oxide]] catalyst.<ref name=":10" />

US patent 1,569,775 was applied for on 4 September 1924 and issued on 12 January 1926 to BASF;<ref>{{patent|US|1569775}}</ref>  the process used a [[chromium(III) oxide|chromium]] and [[manganese oxide]] [[catalyst]] with extremely vigorous conditions: pressures ranging from 50 to 220 [[atmosphere (unit)|atm]], and temperatures up to 450&nbsp;°C. Modern methanol production has been made more efficient through use of catalysts (commonly copper) capable of operating at lower pressures. The modern low pressure methanol (LPM) process was developed by [[Imperial Chemical Industries|ICI]] in the late 1960s with the technology patent long since expired.<ref>{{patent|US|3326956}}</ref>

During [[World War II]], methanol was used as a fuel in several German military rocket designs, under the name [[List of stoffs|M-Stoff]], and in a roughly 50/50 mixture with [[hydrazine]], known as [[C-Stoff]].

The use of methanol as a motor fuel received attention during the [[1970s energy crisis|oil crises of the 1970s]]. By the mid-1990s, over 20,000 methanol [[flexible fuel vehicle]]s (FFVs) capable of operating on methanol or gasoline were introduced in the US. In addition, low levels of methanol were blended in gasoline fuels sold in Europe during much of the 1980s and early-1990s. Automakers stopped building methanol FFVs by the late-1990s, switching their attention to ethanol-fueled vehicles. While the methanol FFV program was a technical success, rising methanol pricing in the mid- to late-1990s during a period of slumping gasoline pump prices diminished interest in [[methanol fuel]]s.<ref>{{cite book|author1=Halderman, James D. |author2=Martin, Tony |title=Hybrid and alternative fuel vehicles|url={{google books |plainurl=y |id=LqgeAQAAIAAJ}}|year=2009|publisher=Pearson/Prentice Hall|isbn=978-0-13-504414-8}}</ref>

In the early 1970s, a process was developed by [[Mobil]] for [[Methanol to gasoline|producing gasoline]] fuel from methanol.<ref>{{cite web |url=https://ihsmarkit.com/pdf/RP282_toc_173824110917062932.pdf |title=Methanol to Gasoline: A Private Report by the Process Economics Program |author=Ronald Smith |date=1 December 2011 |access-date=4 December 2019 |archive-date=4 December 2019 |archive-url=https://web.archive.org/web/20191204144549/https://ihsmarkit.com/pdf/RP282_toc_173824110917062932.pdf |url-status=live}}</ref>

Between the 1960s and 1980s methanol emerged as a precursor to the feedstock chemicals acetic acid and [[acetic anhydride]]. These processes include the [[Monsanto acetic acid synthesis]], [[Cativa process]], and [[Monsanto process#Tennessee Eastman acetic anhydride process|Tennessee Eastman acetic anhydride process]].

==Applications==

===Production of formaldehyde, acetic acid, methyl ''tert''-butyl ether===
Methanol is primarily converted to formaldehyde, which is widely used in many areas, especially [[Polymer|polymers]]. The conversion entails oxidation:
:{{chem2 | 2 CH3OH + O2 -> 2 CH2O + 2 H2O }}
[[Acetic acid]] can be produced from methanol.
[[File:Cativa-process-catalytic-cycle.png|class=skin-invert-image|center|thumb|400px|The [[Cativa process]] converts methanol into [[acetic acid]].<ref name =Cativa>{{cite journal| title = High productivity methanol carbonylation catalysis using iridium – The Cativa process for the manufacture of acetic acid|author1=Sunley, G. J. |author2=Watson, D. J. | journal = Catalysis Today | year = 2000| volume = 58| issue = 4| pages = 293–307| doi = 10.1016/S0920-5861(00)00263-7}}</ref>]]

Methanol and [[isobutene]] are combined to give [[methyl tert-butyl ether|methyl ''tert''-butyl ether]] (MTBE). MTBE is a major octane booster in gasoline.

===Methanol to hydrocarbons, olefins, gasoline===
Condensation of methanol to produce [[hydrocarbon]]s and even [[aromatic hydrocarbon|aromatic]] systems is the basis of several technologies related to [[gas to liquids]]. These include methanol-to-hydrocarbons (MtH), methanol to gasoline (MtG), methanol to olefins (MtO), and methanol to propylene (MtP). These conversions are catalyzed by [[zeolite]]s as [[heterogeneous catalyst]]s. The MtG process was once commercialized at [[Motunui]] in New Zealand.<ref>{{cite journal|author1=Olsbye, U. |author2=Svelle, S. |author3=Bjorgen, M. |author4=Beato, P. |author5=Janssens, T. V. W. |author6=Joensen, F. |author7=Bordiga, S. |author8=Lillerud, K. P. |title=Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity|journal=Angew. Chem. Int. Ed.|year=2012|volume=51|issue=24|pages=5810–5831|doi=10.1002/anie.201103657|pmid=22511469|bibcode=2012ACIE...51.5810O |hdl=2318/122770 |s2cid=26585752 |hdl-access=free}}</ref><ref>{{cite journal|author1=Tian, P. |author2=Wei, Y. |author3=Ye, M. |author4=Liu, Z. |title=Methanol to Olefins (MTO): From Fundamentals to Commercialization|journal=ACS Catal.|year=2015|volume=5|issue=3|pages=1922–1938|doi=10.1021/acscatal.5b00007|doi-access=free}}</ref>

===Gasoline additive===
The [[European Fuel Quality Directive]] allows fuel producers to blend up to 3% methanol, with an equal amount of cosolvent, with gasoline sold in Europe. In 2019,  it is estimated that [[China]] used as much as 7 million tons of methanol as transportation fuels, representing over 5% of their fuel pool.<ref>{{Cite web |date=April 2024 |title=China: the leader in methanol transportation |url=https://www.methanol.org/wp-content/uploads/2020/04/China-Methanol-Fact-Sheet-1.pdf |access-date=4 June 2024 |website=METHANOL INSTITUTE}}</ref>

===Other chemicals===
Methanol is the precursor to most simple [[methylamine]]s, [[methyl halide]]s, and methyl ethers.<ref name=Ullmann>{{cite book|year=2005|publisher=Wiley-VCH|location=Weinheim|doi=10.1002/14356007.a16_465|author1=Fiedler, E. |author2=Grossmann, G. |author3=Burkhard Kersebohm, D. |author4=Weiss, G. |author5=Witte, C. |title=Ullmann's Encyclopedia of Industrial Chemistry|chapter=Methanol|isbn=978-3-527-30673-2}}</ref> Methyl esters are produced from methanol, including the transesterification of fats and production of [[biodiesel]] via [[transesterification]].<ref>{{Cite news|url=http://www.methanol.org/biodiesel/|title=Biodiesel – METHANOL INSTITUTE|work=METHANOL INSTITUTE|access-date=24 March 2018|archive-date=25 March 2018|archive-url=https://web.archive.org/web/20180325044952/http://www.methanol.org/biodiesel/|url-status=live}}</ref><ref>{{Cite news|url=http://articles.extension.org/pages/27137/biodiesel-production-principles-and-processes|title=Biodiesel Production Principles and Processes – eXtension|access-date=24 March 2018|archive-date=25 March 2018|archive-url=https://web.archive.org/web/20180325105905/http://articles.extension.org/pages/27137/biodiesel-production-principles-and-processes}}</ref>

===Niche and potential uses===
====Energy carrier====
Methanol is a promising [[energy carrier]] because, as a liquid, it is easier to store than hydrogen and natural gas. Its [[energy density]] is, however, lower than [[methane]], per kg. Its combustion energy density is 15.6 [[joule|MJ]]/[[liter|L]] ([[Heat of combustion#Lower heating value|LHV]]), whereas that of ethanol is 24 and gasoline is 33 MJ/L.

Further advantages for methanol is its ready biodegradability and low environmental toxicity. It does not persist in either aerobic (oxygen-present) or anaerobic (oxygen-absent) environments. The half-life for methanol in groundwater is just one to seven days, while many common gasoline components have half-lives in the hundreds of days (such as [[benzene]] at 10–730 days). Since methanol is [[miscibility|miscible]] with water and biodegradable, it is unlikely to accumulate in groundwater, surface water, air or soil.<ref>[http://www.methanol.org/Environment/Resources/Environment/MP-Methanol-Fate.aspx Evaluation of the Fate and Transport of Methanol in the Environment] {{webarchive|url=http://arquivo.pt/wayback/20160516022250/http://www.methanol.org/Environment/Resources/Environment/MP-Methanol-Fate.aspx |date=16 May 2016}}, Malcolm Pirnie, Inc., January 1999.</ref>

====Fuel====
{{Main|Methanol fuel|methanol economy}}
Methanol is occasionally used to fuel [[internal combustion engine]]s. It burns forming carbon dioxide and water:
:{{chem2 | 2 CH3OH + 3 O2 -> 2 CO2 + 4 H2O }}
Methanol fuel has been proposed for ground transportation. The chief advantage of a methanol economy is that it could be adapted to gasoline internal combustion engines with minimum modification to the engines and to the infrastructure that delivers and stores liquid fuel. Its energy density, however, is less than gasoline, meaning more frequent fill ups would be required. However, it is equivalent to super high-octane gasoline in horsepower, and most modern computer-controlled fuel injection systems can already use it.<ref>{{cite web|url=https://www.nationalreview.com/2011/12/methanol-wins-robert-zubrin/|title=Methanol Wins|website=[[National Review]]|date=December 2011|access-date=7 June 2022|archive-date=7 June 2022|archive-url=https://web.archive.org/web/20220607191556/https://www.nationalreview.com/2011/12/methanol-wins-robert-zubrin/|url-status=live}}</ref>

Methanol is an alternative fuel for ships that helps the shipping industry meet increasingly strict emissions regulations. It significantly reduces emissions of [[sulfur oxide]]s (SO<sub>''x''</sub>), [[NOx|nitrogen oxide]]s (NO<sub>''x''</sub>) and particulate matter. Methanol can be used with high efficiency in marine diesel engines after minor modifications using a small amount of pilot fuel (dual fuel).<ref>{{Cite web |title=Methanol as a Marine Fuel |publisher=Methanex Corporation |url=https://www.methanex.com/about-methanol/methanol-marine-fuel |access-date=10 April 2021 |archive-date=21 January 2021 |archive-url=https://web.archive.org/web/20210121005930/https://www.methanex.com/about-methanol/methanol-marine-fuel |url-status=live}}</ref><ref>{{cite report |last1=Andersson |first1=Karin |first2=Carlos |last2=Márquez Salazar |title=Methanol as a Marine Fuel Report |url=http://www.methanol.org/wp-content/uploads/2018/03/FCBI-Methanol-Marine-Fuel-Report-Final-English.pdf |publisher=FC Business Intelligence |year=2015 |access-date=10 April 2021 |archive-date=10 April 2021 |archive-url=https://web.archive.org/web/20210410034653/http://www.methanol.org/wp-content/uploads/2018/03/FCBI-Methanol-Marine-Fuel-Report-Final-English.pdf |url-status=live}}</ref>

In China, methanol fuels industrial boilers, which are used extensively to generate heat and steam for various industrial applications and residential heating. Its use is displacing coal, which is under pressure from increasingly stringent environmental regulations.<ref>{{Cite web |title=Methanol as an Industrial Boiler Fuel |publisher=Methanex Corporation |url=https://www.methanex.com/about-methanol/methanol-industrial-boiler-fuel |access-date=10 April 2021 |archive-date=20 January 2021 |archive-url=https://web.archive.org/web/20210120232602/https://www.methanex.com/about-methanol/methanol-industrial-boiler-fuel |url-status=live}}</ref>

[[Direct-methanol fuel cell]]s are unique in their low temperature, atmospheric pressure operation, which lets them be greatly miniaturized.<ref>{{Cite journal | last1 = Kamitani | first1 = A. | last2 = Morishita | first2 = S. | last3 = Kotaki | first3 = H. | last4 = Arscott | first4 = S. | title = Miniaturized microDMFC using silicon microsystems techniques: Performances at low fuel flow rates | doi = 10.1088/0960-1317/18/12/125019 | journal = Journal of Micromechanics and Microengineering | volume = 18 | issue = 12 | article-number = 125019 | year = 2008 | bibcode = 2008JMiMi..18l5019K | s2cid = 110214840 | url = https://hal.archives-ouvertes.fr/hal-02347363/file/kamitani_et_al_2008.pdf | access-date = 30 October 2021 | archive-date = 21 November 2021 | archive-url = https://web.archive.org/web/20211121004627/https://hal.archives-ouvertes.fr/hal-02347363/file/kamitani_et_al_2008.pdf | url-status = live}}</ref><ref>{{Cite journal | last1 = Kamitani | first1 = A. | last2 = Morishita | first2 = S. | last3 = Kotaki | first3 = H. | last4 = Arscott | first4 = S. | title = Microfabricated microfluidic fuel cells | doi = 10.1016/j.snb.2009.11.014 | journal = Sensors and Actuators B: Chemical | volume = 154 | issue = 2 | page = 174 | year = 2011| bibcode = 2011SeAcB.154..174K }}</ref> This, combined with the relatively easy and safe storage and handling of methanol, may open the possibility of fuel cell-powered [[consumer electronics]], such as laptop computers and mobile phones.<ref>{{cite web|url=http://www.compukiss.com/populartopics/tech_gadgetshtm/article887.htm|title=Methanol Laptop Fuel|author=Berger, Sandy|publisher=Compu·Kiss|date=30 September 2006|access-date=22 May 2007|archive-date=3 February 2007|archive-url=https://web.archive.org/web/20070203144642/http://www.compukiss.com/populartopics/tech_gadgetshtm/article887.htm}}</ref>

Methanol is also a widely used fuel in camping and boating stoves. Methanol burns well in an unpressurized burner, so alcohol stoves are often very simple, sometimes little more than a cup to hold fuel. This lack of complexity makes them a favorite of hikers who spend extended time in the wilderness. Similarly, the alcohol can be gelled to reduce risk of leaking or spilling, as with the brand "[[Sterno]]".

Methanol is mixed with water and injected into high performance diesel and gasoline engines for an increase of power and a decrease in intake air temperature in a process known as [[Water injection (engines)|water methanol injection]].

====Other applications====
Methanol is used as a [[Denaturation_(food)|denaturant]] for ethanol, the product being known as ''denatured alcohol'' or ''methylated spirit''. This was commonly used during the [[US prohibition]] to discourage consumption of [[Moonshine|bootleg]]ged liquor, and ended up causing several deaths.<ref>{{cite web |last=Blum |first=Deborah |url=http://www.slate.com/id/2245188/ |title=The little-told story of how the U.S. government poisoned alcohol during Prohibition |website=Slate Magazine |date=19 February 2010 |access-date=10 June 2010 |archive-date=6 August 2018 |archive-url=https://web.archive.org/web/20180806132641/http://www.slate.com/articles/health_and_science/medical_examiner/2010/02/the_chemists_war.html |url-status=live}}</ref>

It is sometimes used as a fuel in alcohol lamps, portable fire pits and camping stoves.

Methanol is used as a [[solvent]] and as an [[antifreeze (coolant)|antifreeze]] in [[Pipeline transport|pipelines]] and [[windshield washer fluid]]. Methanol was used as an automobile coolant antifreeze in the early 1900s.<ref>{{cite journal | doi = 10.1021/ie50257a020| title = Methanol Antifreeze and Methanol Poisoning| journal = Industrial & Engineering Chemistry| volume = 23| issue = 5| page = 551| year = 1931| last1 = Yant | first1 = W. P.| last2 = Schrenk | first2 = H. H.|author3=[[Royd R. Sayers|Sayers, R. R.]]}}</ref> As of May 2018, methanol was banned in the EU for use in windscreen washing or defrosting due to its risk of human consumption<ref>{{CELEX|id=32018R0589|text=Commission Regulation (EU) 2018/589 of 18 April 2018 amending Annex XVII to Regulation (EC) No 1907/2006 of the European Parliament and of the Council concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) as regards methanol}}</ref><ref>{{CELEX|id=32018R0589R(01)|text=Corrigendum to Commission Regulation (EU) 2018/589 of 18 April 2018 amending Annex XVII to Regulation (EC) No 1907/2006 of the European Parliament and of the Council concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) as regards methanol}}</ref> as a result of [[2012 Czech Republic methanol poisonings]].<ref>{{cite web|title=Annex XV Restriction Report: Proposal For a Restriction Substance Name: Methanol – table D.1-4-page 79|date=2015-01-16|url=https://echa.europa.eu/documents/10162/78b0f856-3751-434b-b6bc-6d33cd630c85|access-date=2024-11-29|archive-date=2021-05-26|archive-url=https://web.archive.org/web/20210526070242/https://echa.europa.eu/documents/10162/78b0f856-3751-434b-b6bc-6d33cd630c85|url-status=live}}</ref>

In some [[Sewage treatment|wastewater treatment plants]], a small amount of methanol is added to [[wastewater]] to provide a carbon food source for the [[denitrifying bacteria]], which convert [[nitrate]]s to [[nitrogen]] gas and reduce the nitrification of sensitive [[aquifer]]s.

Methanol is used as a destaining agent in [[polyacrylamide gel electrophoresis]].

==Production==

===From synthesis gas===
Carbon monoxide and hydrogen react over a catalyst to produce methanol. Today, the most widely used catalyst is a mixture of copper and [[zinc oxide]]s, [[catalyst support|supported]] on [[alumina]], as first used by [[Imperial Chemical Industries|ICI]] in 1966. At 5–10 MPa (50–100&nbsp;atm) and {{convert|250|C}}, the reaction

:{{chem2 | CO + 2 H2 -> CH3OH }}

is characterized by high selectivity (>99.8%). The production of [[syngas|synthesis gas]] from methane produces three [[Mole (unit)|mole]]s of hydrogen for every mole of carbon monoxide, whereas the synthesis consumes only two moles of hydrogen gas per mole of carbon monoxide. One way of dealing with the excess hydrogen is to inject [[carbon dioxide]] into the methanol synthesis reactor, where it, too, reacts to form methanol according to the equation

:{{chem2 | CO2 + 3 H2 -> CH3OH + H2O }}

In terms of mechanism, the process occurs via initial conversion of CO into {{chem2|CO2}}, which is then [[hydrogenation|hydrogenated]]:<ref>Deutschmann, Olaf; Knözinger, Helmut; Kochloefl, Karl and Turek, Thomas (2012) "Heterogeneous Catalysis and Solid Catalysts, 3. Industrial Applications" in ''Ullmann's Encyclopedia of Industrial Chemistry''. Wiley-VCH, Weinheim. {{doi|10.1002/14356007.o05_o03}}</ref>

:{{chem2 | CO2 + 3 H2 -> CH3OH + H2O }}

where the {{chem2|H2O}} byproduct is recycled via the [[water gas shift reaction|water-gas shift reaction]]

:{{chem2 | CO + H2O -> CO2 + H2 }}

This gives an overall reaction

:{{chem2 | CO + 2 H2 -> CH3OH }}

which is the same as listed above. In a process closely related to methanol production from synthesis gas, a feed of hydrogen and {{chem2|CO2}} can be used directly.<ref>{{Cite journal|last1=Bozzano|first1=Giulia|last2=Manenti|first2=Flavio|date=2016|title=Efficient methanol synthesis: Perspectives, technologies and optimization strategies|url=https://www.sciencedirect.com/science/article/pii/S0360128515300484|journal=Progress in Energy and Combustion Science|language=en|volume=56|page=76|doi=10.1016/j.pecs.2016.06.001|bibcode=2016PECS...56...71B |issn=0360-1285|url-access=subscription}}</ref> The main advantage of this process is that [[Carbon capture and storage|captured {{chem2|CO2}}]] and hydrogen sourced from [[Electrolysis of water|electrolysis]] could be used, removing the dependence on fossil fuels.

===Biosynthesis===
The catalytic conversion of methane to methanol is effected by enzymes including [[methane monooxygenase]]s. These enzymes are mixed-function oxygenases, i.e. oxygenation is coupled with production of water<ref>{{cite journal|title=Mechanistic Studies on the Hydroxylation of Methane by Methane Monooxygenase|author=Mu-Hyun Baik |author2=Martin Newcomb |author3=Richard A. Friesner |author4=Stephen J. Lippard |journal=Chem. Rev.|year=2003|volume=103|issue=6|pages=2385–2420|doi=10.1021/cr950244f|pmid=12797835}}</ref> and [[Nicotinamide adenine dinucleotide|{{chem2|NAD+}}]]:<ref name=":0" />

:{{chem2 | CH4 + O2 + NADPH + H+ -> CH3OH + H2O + NAD+ }}

Both Fe- and Cu-dependent enzymes have been characterized.<ref name=":0">{{cite journal|author1=Lawton, T. J. |author2=Rosenzweig, A. C. |title=Biocatalysts for methane conversion: big progress on breaking a small substrate|journal=Curr. Opin. Chem. Biol.|year=2016|volume=35|pages=142–149|doi=10.1016/j.cbpa.2016.10.001|pmid=27768948|pmc=5161620}}</ref> Intense but largely fruitless efforts have been undertaken to emulate this reactivity.<ref name="Alayon">{{Cite journal|last1=Alayon|first1=E. M. C.|last2=Nachtegaal|first2=M.|last3=Ranocchiari|first3=M.|last4=Van Bokhoven|first4=J. A.|title=Catalytic Conversion of Methane to Methanol Using Cu-Zeolites|doi=10.2533/chimia.2012.668|journal=CHIMIA International Journal for Chemistry|volume=66|issue=9|pages=668–674|year=2012|pmid=23211724|url=https://www.dora.lib4ri.ch/psi/islandora/object/psi%3A20913|doi-access=free|access-date=10 May 2021|archive-date=26 May 2021|archive-url=https://web.archive.org/web/20210526070248/https://www.dora.lib4ri.ch/psi/islandora/object/psi%3A20913|url-status=live}}</ref><ref name="Catalytic and Mechanic Insights">{{Cite journal|doi=10.1002/chem.201202802|pmid=23150452|title=Catalytic and Mechanistic Insights of the Low-Temperature Selective Oxidation of Methane over Cu-Promoted Fe-ZSM-5|journal=Chemistry: A European Journal|volume=18|issue=49|pages=15735–45|year=2012|last1=Hammond|first1=C.|last2=Jenkins|first2=R. L.|last3=Dimitratos|first3=N.|last4=Lopez-Sanchez|first4=J. A.|last5=Ab Rahim|first5=M. H.|last6=Forde|first6=M.M.|last7=Thetford|first7=A.|last8=Murphy|first8=D.M.|last9=Hagen|first9=H.|last10=Stangland|first10=E.E.|last11=Moulijn|first11=J.M.|last12=Taylor|first12=S. H.|last13=Willock|first13=D. J.|last14=Hutchings|first14=G.J.}}</ref> Methanol is more easily oxidized than is the feedstock methane, so the reactions tend not to be selective. Some strategies exist to circumvent this problem. Examples include [[Shilov system]]s and Fe- and Cu-containing zeolites.<ref>{{Cite journal|last1=Snyder|first1=Benjamin E. R.|last2=Bols|first2=Max L.|last3=Schoonheydt|first3=Robert A.|last4=Sels|first4=Bert F.|last5=Solomon|first5=Edward I.|date=19 December 2017|title=Iron and Copper Active Sites in Zeolites and Their Correlation to Metalloenzymes|journal=Chemical Reviews|volume=118|issue=5|pages=2718–2768|doi=10.1021/acs.chemrev.7b00344|pmid=29256242|url=https://limo.libis.be/primo-explore/fulldisplay?docid=LIRIAS1644877&context=L&vid=Lirias&search_scope=Lirias&tab=default_tab&lang=en_US&fromSitemap=1|access-date=25 September 2021|archive-date=26 May 2021|archive-url=https://web.archive.org/web/20210526075141/https://limo.libis.be/primo-explore/fulldisplay?docid=LIRIAS1644877&context=L&vid=Lirias&search_scope=Lirias&tab=default_tab&lang=en_US&fromSitemap=1|url-status=live|url-access=subscription}}</ref> These systems do not necessarily mimic the mechanisms employed by [[metalloenzymes]], but draw some inspiration from them. Active sites can vary substantially from those known in the enzymes. For example, a dinuclear active site is proposed in the [[Methane monooxygenase|sMMO]] enzyme, whereas a mononuclear iron ([[alpha-Oxygen|alpha-oxygen]]) is proposed in the Fe-zeolite.<ref>{{Cite journal|last1=Snyder|first1=Benjamin E. R.|last2=Vanelderen|first2=Pieter|last3=Bols|first3=Max L.|last4=Hallaert|first4=Simon D.|last5=Böttger|first5=Lars H.|last6=Ungur|first6=Liviu|last7=Pierloot|first7=Kristine|last8=Schoonheydt|first8=Robert A.|last9=Sels|first9=Bert F.|s2cid=4467834|title=The active site of low-temperature methane hydroxylation in iron-containing zeolites|journal=Nature|volume=536|issue=7616|pages=317–321|doi=10.1038/nature19059|pmid=27535535|bibcode=2016Natur.536..317S|year=2016}}</ref>

Global emissions of methanol by plants are estimated at between 180 and 250 million tons per year.<ref>{{Cite journal |last1=Stavrakou |first1=T. |last2=Guenther |first2=A. |last3=Razavi |first3=A. |last4=Clarisse |first4=L. |last5=Clerbaux |first5=C. |last6=Coheur |first6=P.-F. |last7=Hurtmans |first7=D. |last8=Karagulian |first8=F. |last9=De Mazière |first9=M. |last10=Vigouroux |first10=C. |last11=Amelynck |first11=C. |last12=Schoon |first12=N. |last13=Laffineur |first13=Q. |last14=Heinesch |first14=B. |last15=Aubinet |first15=M. |date=25 May 2011 |title=First space-based derivation of the global atmospheric methanol emission fluxes |url=https://acp.copernicus.org/articles/11/4873/2011/ |journal=Atmospheric Chemistry and Physics |language=en |volume=11 |issue=10 |pages=4873–4898 |doi=10.5194/acp-11-4873-2011 |bibcode=2011ACP....11.4873S |s2cid=54685577 |issn=1680-7324 |doi-access=free |access-date=26 September 2022 |archive-date=26 September 2022 |archive-url=https://web.archive.org/web/20220926161749/https://acp.copernicus.org/articles/11/4873/2011/ |url-status=live|hdl=2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/93180 |hdl-access=free }}</ref> This is between two and three times larger than man-made industrial production of methanol.

== Green methanol ==
As of 2023, 0.2% of global methanol production is produced in ways that have relatively low greenhouse gas emissions; this is known as "green" methanol.<ref name=":2">{{Cite journal |last1=Sollai |first1=Stefano |last2=Porcu |first2=Andrea |last3=Tola |first3=Vittorio |last4=Ferrara |first4=Francesca |last5=Pettinau |first5=Alberto |date=1 February 2023 |title=Renewable methanol production from green hydrogen and captured CO2: A techno-economic assessment |journal=Journal of CO2 Utilization |volume=68 |article-number=102345 |doi=10.1016/j.jcou.2022.102345 |issn=2212-9820|doi-access=free|hdl=11584/435627 |hdl-access=free }}</ref> Most green methanol is produced from gasification of [[Biomass (energy)|biomass]].<ref name=":2" /> [[Syngas]] is produced from biomass [[gasification]] and further converted into green methanol.<ref>{{Cite journal |last=Sasidhar |first=Nallapaneni |date=November 2023 |title=Carbon Neutral Fuels and Chemicals from Standalone Biomass Refineries |url=https://www.ijee.latticescipub.com/wp-content/uploads/papers/v3i2/B1845113223.pdf |access-date=3 December 2023 |journal=Indian Journal of Environment Engineering |issn=2582-9289 |volume=3 |issue=2|pages=1–8 |doi=10.54105/ijee.B1845.113223 |s2cid=265385618}}</ref>

Another method of producing green methanol involves combining hydrogen, carbon dioxide, and a catalyst under high heat and pressure.<ref name=":2" /> To be classified as green methanol, the hydrogen must be [[Green hydrogen|produced using renewable electricity]],<ref name=":2" /> and the carbon dioxide must be from [[carbon capture and storage]], [[direct air capture]] or biomass of recent origin.<ref name=":2" /> Some definitions of green methanol specify that the carbon dioxide must be captured during the burning of [[bioenergy]].<ref>{{Cite web |date=8 March 2022 |title=Green Hydrogen for Industry: A Guide to Policy Making |url=https://www.irena.org/publications/2022/Mar/Green-Hydrogen-for-Industry |access-date=4 September 2023 |website=www.irena.org |page=18 |language=en}}</ref>

==Quality specifications and analysis==
Methanol is available commercially in various purity grades. Commercial methanol is generally classified according to ASTM purity grades A and AA. Both grade A and grade AA purity are 99.85% methanol by weight. Grade "AA" methanol contains trace amounts of ethanol as well.<ref name=":10">{{Cite journal|last1=Bozzano|first1=Giulia|last2=Manenti|first2=Flavio|date=1 September 2016|title=Efficient methanol synthesis: Perspectives, technologies and optimization strategies|url=https://www.sciencedirect.com/science/article/abs/pii/S0360128515300484|journal=Progress in Energy and Combustion Science|language=en|volume=56|pages=71–105|doi=10.1016/j.pecs.2016.06.001|bibcode=2016PECS...56...71B |issn=0360-1285|access-date=25 September 2021|archive-date=25 September 2021|archive-url=https://web.archive.org/web/20210925190644/https://www.sciencedirect.com/science/article/abs/pii/S0360128515300484|url-status=live|url-access=subscription}}</ref>

Methanol for chemical use normally corresponds to Grade AA. In addition to water, typical impurities include [[acetone]] and ethanol (which are very difficult to separate by distillation). UV-vis spectroscopy is a convenient method for detecting aromatic impurities. Water content can be determined by the [[Karl Fischer titration|Karl-Fischer titration]].

==Safety==
Methanol is highly flammable. Its vapours are slightly denser than air and can travel to a distant ignition source and ignite. Methanol fires should be extinguished with [[dry chemical]], [[carbon dioxide]], water spray or alcohol-resistant foam.<ref name= CDC_card/> Methanol flames are invisible in daylight. 

===Toxicity===
{{Main|Methanol toxicity}}
{{See also|List of methanol poisoning incidents}}
Ingestion of as little as 3.16 grams of methanol can cause irreversible [[Toxic and nutritional optic neuropathy|optic nerve damage]], and the oral [[LD50]] for humans is estimated to be 56.2 grams.<ref name="Moon">{{cite journal |title=Estimations of the lethal and exposure doses for representative methanol symptoms in humans|year=2017 |pmc=5625597 |last1=Moon |first1=C. S. |journal=Annals of Occupational and Environmental Medicine |volume=29 |article-number=44 |doi=10.1186/s40557-017-0197-5 |pmid=29026612 |doi-access=free }}</ref> The [[reference dose]] for methanol is 0.5&nbsp;mg/kg in a day.<ref>{{Cite web|url=http://www.epa.gov/iris/subst/0305.htm|title=Integrated Risk Information System|publisher=US EPA, ORD, NCEA, IRISD|date=15 March 2013|access-date=18 February 2013|archive-date=5 December 2012|archive-url=https://web.archive.org/web/20121205004930/http://www.epa.gov/iris/subst/0305.htm}}</ref><ref>{{cite web |url=https://cfpub.epa.gov/ncea/iris/iris_documents/documents/toxreviews/0305tr.pdf |title=Toxicological Review of Methanol (Noncancer) (CAS No. 67-56-1) In Support of Summary Information on the Integrated Risk Information System (IRIS) |id=EPA/635/R-11/001Fa |publisher=[[United States Environmental Protection Agency|EPA]] |date=September 2013 |access-date=30 March 2021 |archive-date=31 March 2021 |archive-url=https://web.archive.org/web/20210331010417/https://cfpub.epa.gov/ncea/iris/iris_documents/documents/toxreviews/0305tr.pdf }}</ref> Toxic effects begin hours after ingestion, and antidotes can often prevent permanent damage.<ref name="Vale">{{Cite journal |author=Vale A |title=Methanol |journal=Medicine |volume=35 |issue=12 |pages=633–4 |year=2007|doi=10.1016/j.mpmed.2007.09.014}}</ref> Because of its similarities in both appearance and odor to [[ethanol]] (the alcohol in beverages) or [[isopropyl alcohol]], it is difficult to differentiate between the three.<ref>{{Cite encyclopedia |last=Wade |first=Leroy G. |title=Physical properties of alcohols |url=https://www.britannica.com/science/alcohol/Physical-properties-of-alcohols |access-date=2024-08-18 |encyclopedia=Britannica |language=en}}</ref>

Methanol is [[Toxicity|toxic]] by two mechanisms. First, methanol can be fatal due to effects on the central nervous system, acting as a [[Central nervous system depression|central nervous system depressant]] in the same manner as [[Alcohol intoxication#Acute alcohol poisoning|ethanol poisoning]]. Second, in a process of [[toxication]], it is [[metabolism|metabolised]] to [[formic acid]] (which is present as the formate ion) via [[formaldehyde]] in a process initiated by the [[enzyme]] [[alcohol dehydrogenase]] in the [[liver]].<ref name="Schep">{{Cite journal |vauthors=Schep LJ, Slaughter RJ, Vale JA, Beasley DM |s2cid=6367081 |title=A seaman with blindness and confusion |journal=[[BMJ]] |volume=339 |article-number=b3929 |date=2009 |url=http://www.bmj.com/cgi/content/full/339/sep30_1/b3929 |doi=10.1136/bmj.b3929 |pmid=19793790 |access-date=3 October 2009 |archive-date=8 October 2009 |archive-url=https://web.archive.org/web/20091008081309/http://www.bmj.com/cgi/content/full/339/sep30_1/b3929 |url-status=live|url-access=subscription }}</ref> Methanol is converted to formaldehyde via alcohol dehydrogenase (ADH) and formaldehyde is converted to formic acid (formate) via [[aldehyde dehydrogenase]] (ALDH). The conversion to formate via ALDH proceeds completely, with no detectable formaldehyde remaining.<ref name=noCHOH>{{Cite journal |vauthors=McMartin KE, Martin-Amat G, Noker PE, Tephly TR |title=Lack of a role for formaldehyde in methanol poisoning in the monkey |journal=Biochem. Pharmacol. |volume=28 |issue=5 |pages=645–9 |year=1979 |pmid=109089 |doi= 10.1016/0006-2952(79)90149-7}}</ref> Formate is toxic because it inhibits mitochondrial [[cytochrome c oxidase]], causing [[hypoxia (medical)|hypoxia]] at the cellular level, and [[metabolic acidosis]], among a variety of other metabolic disturbances.<ref>{{Cite journal |vauthors=Liesivuori J, Savolainen H |title=Methanol and formic acid toxicity: biochemical mechanisms |journal=Pharmacol. Toxicol. |volume=69 |issue=3 |pages=157–63 |date=September 1991 |pmid=1665561 |doi= 10.1111/j.1600-0773.1991.tb01290.x}}</ref>

<!-- Epidemiology, prognosis, and history -->
Outbreaks of methanol poisoning have occurred primarily due to contamination of [[Ethanol|drinking alcohol]].<!--<ref name=EM2016 /> --> It is also worth noting that ethanol is a natural antidote to methanol poisoning.<ref>{{cite journal | url=https://academic.oup.com/ajhp/article-abstract/38/7/1024/5200360 | doi=10.1093/ajhp/38.7.1024 | title=Oral ethanol doses in patients with methanol poisoning | date=1981 | last1=Peterson | first1=Charles D. | journal=American Journal of Health-System Pharmacy | volume=38 | issue=7 | pages=1024–1027 | url-access=subscription }}</ref> Contaminated batches of alcohol contained a much higher concentration of methanol than ethanol, which did not provide a sufficient dose of the antidote and caused it to be ineffective. This is more common in the [[Developing country|developing world]].<ref name=EM2016>{{Cite journal|last1=Beauchamp|first1=GA|last2=Valento|first2=M|title=Toxic Alcohol Ingestion: Prompt Recognition And Management in the Emergency Department|journal=Emergency Medicine Practice|date=September 2016|volume=18|issue=9|pages=1–20|pmid=27538060}}</ref> In 2013 more than 1700 cases nonetheless occurred in the United States.<!--<ref name=Fer2016 /> --> Those affected are often adult men.<ref name=Fer2016>{{Cite book|last1=Ferri|first1=Fred F.|title=Ferri's Clinical Advisor 2017: 5 Books in 1|date=2016|publisher=Elsevier Health Sciences|isbn=978-0-323-44838-3|page=794|url=https://books.google.com/books?id=rRhCDAAAQBAJ&pg=PA794|access-date=22 August 2019|archive-date=10 January 2023|archive-url=https://web.archive.org/web/20230110020409/https://books.google.com/books?id=rRhCDAAAQBAJ&pg=PA794|url-status=live}}</ref> Outcomes may be good with early treatment.<ref name=Kr2012>{{Cite journal|last1=Kruse|first1=JA|title=Methanol and ethylene glycol intoxication|journal=Critical Care Clinics|date=October 2012|volume=28|issue=4|pages=661–711|pmid=22998995|doi=10.1016/j.ccc.2012.07.002}}</ref> The toxicity of methanol was described as early as 1856.<ref>{{Cite book|last1=Clary|first1=John J.|title=The Toxicology of Methanol|date=2013|publisher=John Wiley & Sons|isbn=978-1-118-35310-3|page=3.4.1|url={{Google books |plainurl=y |id=xSs8oDQV4uYC&|page=44}}}}</ref>

Because of its toxic properties, methanol is frequently used as a denaturant additive for ethanol manufactured for industrial uses. This addition of methanol exempts industrial ethanol (commonly known as "[[denatured alcohol]]" or "methylated spirit") from liquor [[Excise tax in the United States|excise taxation]] in the US and other countries.

==See also==
*[[Aminomethanol]]
*[[Methanol (data page)]]
*[[Methanol economy]]
*[[tert-Butyl alcohol|Trimethyl carbinol]]

==References==
{{Reflist}}

==Further reading==
*[[Robert Boyle]], ''[[The Sceptical Chymist]]'' (1661) – contains account of distillation of wood alcohol.
*{{Cite encyclopedia |title=Alcohols |encyclopedia=Encyclopedia of Liquid Fuels |publisher=De Gruyter |last=Schmidt |first=Eckart W.  |date=2022 |pages=2–12 |doi=10.1515/9783110750287-001 |isbn=978-3-11-075028-7 |chapter=Methanol}}

==External links==
* {{ICSC|0057|00}}
* [https://www.cdc.gov/niosh/topics/methyl-alcohol/ Methyl Alcohol (Methanol)] CDC/NIOSH, links to safety information
* [https://www.cdc.gov/niosh/npg/npgd0397.html CDC – NIOSH Pocket Guide to Chemical Hazards – Methyl Alcohol]
* [http://www.npi.gov.au/resource/methanol Methanol Fact Sheet] – National Pollutant Inventory

{{Alcohols}}
{{Neurotoxins}}
{{Wood products}}
{{Molecules detected in outer space}}
{{GABAAR PAMs}}

{{Authority control}}

[[Category:Methanol| ]]
[[Category:Alkanols]]
[[Category:Alcohol solvents]]
[[Category:Anatomical preservation]]
[[Category:Biofuels]]
[[Category:Energy storage]]
[[Category:Human metabolites]]
[[Category:Neurotoxins]]
[[Category:Oxygenates]]
[[Category:Commodity chemicals]]
[[Category:GABAA receptor positive allosteric modulators]]
[[Category:Rocket fuels]]