:Dimethyl ether

Approximately 50,000 tons were produced in 1985 in Western Europe by dehydration of methanol:Manfred Müller, Ute Hübsch, "Dimethyl Ether" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. {{doi|10.1002/14356007.a08_541}}

:{{chem2|2 CH3OH -> (CH3)2O + H2O}}

The required methanol is obtained from synthesis gas (syngas).{{cite web|url=http://www.chemsystems.com/reports/search/docs/abstracts/0708S3_abs.pdf|title=CHEMSYSTEMS.COM|website=www.chemsystems.com|access-date=1 April 2018|archive-url=https://web.archive.org/web/20091122170413/http://www.chemsystems.com/reports/search/docs/abstracts/0708S3_abs.pdf|archive-date=22 November 2009|url-status=dead}} Other possible improvements call for a dual catalyst system that permits both methanol synthesis and dehydration in the same process unit, with no methanol isolation and purification.P.S. Sai Prasad et al., Fuel Processing Technology, 2008, 89, 1281.

Both the one-step and two-step processes above are commercially available. The two-step process is relatively simple and start-up costs are relatively low. A one-step liquid-phase process is in development.{{cite web|url=http://www.airproducts.com/Technology/product_offering.asp?reg=GBL&intProductTypeCategoryId=95&intRegionalMarketSegment=0|title=Air Products Technology Offerings|website=airproducts.com|access-date=1 April 2018|archive-url=https://web.archive.org/web/20071212191702/http://www.airproducts.com/technology/product_offering.asp?reg=GBL&intProductTypeCategoryId=95&intRegionalMarketSegment=0|archive-date=12 December 2007|url-status=dead}}

Dimethyl ether is a synthetic second generation biofuel (BioDME), which can be produced from lignocellulosic biomass.{{cite web|url=http://www.biodme.eu/|title=BioDME|website=www.biodme.eu|access-date=1 April 2018|archive-date=10 April 2020|archive-url=https://web.archive.org/web/20200410183454/http://www.biodme.eu/|url-status=live}} The EU is considering BioDME in its potential biofuel mix in 2030;{{cite web|url=http://ec.europa.eu/research/energy/pdf/draft_vision_report_en.pdf|title=Biofuels in the European Union, 2006|website=europa.eu|access-date=1 April 2018|archive-date=3 December 2019|archive-url=https://web.archive.org/web/20191203221230/http://ec.europa.eu/research/energy/pdf/draft_vision_report_en.pdf|url-status=live}} It can also be made from biogas or methane from animal, food, and agricultural waste,{{Cite web |url=http://oberonfuels.com/2013/06/07/oberon-fuels-brings-production-units-online-launching-the-first-north-american-fuel-grade-dme-facilities/ |title=Oberon Fuels Brings Production Units Online, Launching the First North American Fuel-grade DME Facilities |date=7 June 2013 |access-date=2018-08-04 |archive-date=2021-05-06 |archive-url=https://web.archive.org/web/20210506070121/https://oberonfuels.com/2013/06/07/oberon-fuels-brings-production-units-online-launching-the-first-north-american-fuel-grade-dme-facilities/ |url-status=live }}{{Cite web |url=http://siteresources.worldbank.org/EXTGGFR/Resources/AG_utilization_via_mini_GTL.pdf?resourceurlname=AG_utilization_via_mini_GTL.pdf |title=Associated Gas Utilization via mini GTL |access-date=2018-08-04 |archive-date=2018-08-04 |archive-url=https://web.archive.org/web/20180804201342/http://siteresources.worldbank.org/EXTGGFR/Resources/AG_utilization_via_mini_GTL.pdf?resourceurlname=AG_utilization_via_mini_GTL.pdf |url-status=live }} or even from shale gas or natural gas.{{Cite book |doi = 10.1016/S0167-2991(04)80081-8|chapter = Direct Dimethyl Ether (DME) synthesis from natural gas|title = Natural Gas Conversion VII, Proceedings of the 7th Natural Gas Conversion Symposium|volume = 147|pages = 379–384|series = Studies in Surface Science and Catalysis|year = 2004|last1 = Ogawa|first1 = Takashi|last2 = Inoue|first2 = Norio|last3 = Shikada|first3 = Tutomu|last4 = Inokoshi|first4 = Osamu|last5 = Ohno|first5 = Yotaro|isbn = 9780444515995}}

The Volvo Group is the coordinator for the European Community Seventh Framework Programme project BioDME{{cite web |url=http://www.volvo.com/group/global/en-gb/newsmedia/pressreleases/NewsItemPage.htm?channelId=2184&ItemID=47984&sl=en-gb |title=Home {{pipe}} Volvo Group |access-date=2011-11-04 |url-status=dead |archive-url=https://web.archive.org/web/20090525045327/http://www.volvo.com/group/global/en-gb/newsmedia/pressreleases/NewsItemPage.htm?channelId=2184&ItemID=47984&sl=en-gb |archive-date=2009-05-25 }}{{cite web|url=http://www.volvo.com/group/global/en-gb/volvo+group/ourvalues/environment/renewable_fuels/biodme/biodme.htm|title=Volvo Group - Driving prosperity through transport solutions|website=www.volvo.com|access-date=1 April 2018|archive-date=6 June 2020|archive-url=https://web.archive.org/web/20200606064458/https://www.volvogroup.com/en-en/home.html|url-status=dead}} where Chemrec's BioDME pilot plant is based on black liquor gasification in Piteå, Sweden.[http://www.chemrec.se/admin/UploadFile.aspx?path=/UserUploadFiles/Pressreleaser%202010/The-first-BioDME-plant-in-the-world-inaugurated_1.pdf Chemrec press release September 9, 2010] {{webarchive|url=https://web.archive.org/web/20170612010101/http://www.chemrec.se/admin/UploadFile.aspx?path=%2FUserUploadFiles%2FPressreleaser+2010%2FThe-first-BioDME-plant-in-the-world-inaugurated_1.pdf |date=June 12, 2017 }}

The largest use of dimethyl ether is as the feedstock for the production of the methylating agent, dimethyl sulfate, which entails its reaction with sulfur trioxide:

:{{chem2|CH3OCH3 + SO3 -> (CH3)2SO4}}

Dimethyl ether can also be converted into acetic acid using carbonylation technology related to the Monsanto acetic acid process:

:{{chem2|(CH3)2O + 2 CO + H2O -> 2 CH3CO2H}}

Dimethyl ether is a low-temperature solvent and extraction agent, applicable to specialised laboratory procedures. Its usefulness is limited by its low boiling point ({{convert|-23|C}}), but the same property facilitates its removal from reaction mixtures. Dimethyl ether is the precursor to the useful alkylating agent, trimethyloxonium tetrafluoroborate.{{OrgSynth | author = T. J. Curphey | collvol = 6 | year = 1988| collvolpages = 1019 | prep = CV6P1019| title = Trimethyloxonium tetrafluoroborate}}

A mixture of dimethyl ether and propane is used in some over-the-counter "freeze spray" products to treat warts by freezing them.{{cite news | url = http://www.pharmacytimes.com/issue/pharmacy/2006/2006-07/2006-07-5674 | date = July 2006 | title = A Pharmacist's Guide to OTC Therapy: OTC Treatments for Warts | access-date = 2009-05-02 | archive-url = https://web.archive.org/web/20100617043246/http://www.pharmacytimes.com/issue/pharmacy/2006/2006-07/2006-07-5674 | archive-date = 2010-06-17 | url-status = dead }}{{Cite web |url=https://www.fda.gov/cdrh/pdf3/K030838.pdf |title=Archived copy |website=Food and Drug Administration |access-date=2019-12-16 |archive-date=2009-04-20 |archive-url=https://web.archive.org/web/20090420005111/http://www.fda.gov/cdrh/pdf3/k030838.pdf |url-status=dead }} In this role, it has supplanted halocarbon compounds (Freon).

Dimethyl ether is also a component of certain high temperature "Map-Pro" blowtorch gas blends, supplanting the use of methyl acetylene and propadiene mixtures.{{Cite web |url=http://images.toolbank.com/downloads/cossh/0482.pdf |title=Archived copy |access-date=2016-03-02 |archive-date=2016-12-20 |archive-url=https://web.archive.org/web/20161220132220/http://images.toolbank.com/downloads/cossh/0482.pdf |url-status=dead}}

Dimethyl ether is also used as a propellant in aerosol products. Such products include hair spray, bug spray and some aerosol glue products.

File:Chemrec 5 - small.JPG

A potentially major use of dimethyl ether is as substitute for propane in LPG used as fuel in household and industry.{{cite web|url=http://aboutdme.org/aboutdme/files/ccLibraryFiles/Filename/000000001519/IDA_Fact_Sheet_1_LPG_DME_Blends.pdf|title=IDA Fact Sheet DME/LPG Blends 2010 v1|website=aboutdme.org|access-date=1 April 2018|archive-date=24 July 2011|archive-url=https://web.archive.org/web/20110724214522/http://aboutdme.org/aboutdme/files/ccLibraryFiles/Filename/000000001519/IDA_Fact_Sheet_1_LPG_DME_Blends.pdf|url-status=usurped}} Dimethyl ether can also be used as a blendstock in propane autogas.{{Cite journal|url= https://doi.org/10.1016/j.jngse.2012.05.012|title= The Status of DME developments in China and beyond, 2012|journal= Journal of Natural Gas Science and Engineering|date= November 2012|volume= 9|pages= 94–107|doi= 10.1016/j.jngse.2012.05.012|last1= Fleisch|first1= T. H.|last2= Basu|first2= A.|last3= Sills|first3= R. A.|access-date= 2020-11-21|archive-date= 2022-05-04|archive-url= https://web.archive.org/web/20220504141337/https://www.sciencedirect.com/science/article/pii/S1875510012000650?via%3Dihub|url-status= live|url-access= subscription}}

It is also a promising fuel in diesel engines,[http://www.nykomb.se/index.php?s=Chemicals nycomb.se, Nycomb Chemicals company] {{webarchive|url=https://web.archive.org/web/20080603115705/http://www.nykomb.se/index.php?s=Chemicals |date=2008-06-03 }} and gas turbines. For diesel engines, an advantage is the high cetane number of 55, compared to that of diesel fuel from petroleum, which is 40–53.{{cite web |url=http://www.topsoe.com/site.nsf/all/BBNN-5PNJ3F?OpenDocument |title=Haldor Topsoe - Products & Services - Technologies - DME - Applications - DME as Diesel Fuel |access-date=2011-11-04 |url-status=dead |archive-url=https://web.archive.org/web/20071008100421/http://www.topsoe.com/site.nsf/all/BBNN-5PNJ3F?OpenDocument |archive-date=2007-10-08 }} topsoe.com Only moderate modifications are needed to convert a diesel engine to burn dimethyl ether. The simplicity of this short carbon chain compound leads to very low emissions of particulate matter during combustion. For these reasons as well as being sulfur-free, dimethyl ether meets even the most stringent emission regulations in Europe (EURO5), U.S. (U.S. 2010), and Japan (2009 Japan).{{cite web |url=http://www.japantransport.com/conferences/2006/03/dme_detailed_information.pdf |title=Archived copy |access-date=2011-11-04 |url-status=dead |archive-url=https://web.archive.org/web/20090107022359/http://www.japantransport.com/conferences/2006/03/dme_detailed_information.pdf |archive-date=2009-01-07 }}, Conference on the Development and Promotion of Environmentally Friendly Heavy Duty Vehicles such as DME Trucks, Washington DC, March 17, 2006

At the European Shell Eco Marathon, an unofficial World Championship for mileage, vehicle running on 100 % dimethyl ether drove 589 km/L (169.8 cm³/100 km), fuel equivalent to gasoline with a 50 cm³ displacement 2-stroke engine. As well as winning they beat the old standing record of 306 km/liter (326.8 cm³/100 km), set by the same team in 2007.{{cite web|url=http://www.ecocar.mek.dtu.dk/Achievements.aspx|title=The Danish Ecocar Team - List of achievements|website=dtu.dk|access-date=1 April 2018|archive-url=https://web.archive.org/web/20091017150928/http://www.ecocar.mek.dtu.dk/Achievements.aspx|archive-date=17 October 2009|url-status=dead}}

To study the dimethyl ether for the combustion process a chemical kinetic mechanism{{Cite journal|url = https://doi.org/10.1016/j.combustflame.2020.04.016|doi = 10.1016/j.combustflame.2020.04.016|title = A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NO interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature|year = 2020|last1 = Shrestha|first1 = Krishna P.|last2 = Eckart|first2 = Sven|last3 = Elbaz|first3 = Ayman M.|last4 = Giri|first4 = Binod R.|last5 = Fritsche|first5 = Chris|last6 = Seidel|first6 = Lars|last7 = Roberts|first7 = William L.|last8 = Krause|first8 = Hartmut|last9 = Mauss|first9 = Fabian|journal = Combustion and Flame|volume = 218|pages = 57–74|hdl = 10754/662921|s2cid = 219772095|hdl-access = free|access-date = 2020-05-18|archive-date = 2022-05-04|archive-url = https://web.archive.org/web/20220504141322/https://www.sciencedirect.com/science/article/pii/S0010218020301607?via%3Dihub|url-status = live}} is required which can be used for Computational fluid dynamics calculation.

Dimethyl ether is a refrigerant with ASHRAE refrigerant designation R-E170. It is also used in refrigerant blends with e.g. ammonia, carbon dioxide, butane and propene.

Dimethyl ether was the first refrigerant. In 1876, the French engineer Charles Tellier bought the ex-Elder-Dempster a 690 tons cargo ship Eboe and fitted a methyl-ether refrigerating plant of his design. The ship was renamed Le Frigorifique and successfully imported a cargo of refrigerated meat from Argentina. However the machinery could be improved and in 1877 another refrigerated ship called Paraguay with a refrigerating plant improved by Ferdinand Carré was put into service on the South American run.[https://archive.org/stream/historyoffrozenm00crituoft/historyoffrozenm00crituoft_djvu.txt A history of the frozen meat trade, page 26-28]http://www.ashrae.org/technology/page/1933#et {{Webarchive|url=https://web.archive.org/web/20120103000626/http://www.ashrae.org/technology/page/1933#et |date=2012-01-03}} ASHRAE list of refrigerants

Unlike other alkyl ethers, dimethyl ether resists autoxidation.A comparative study on the autoxidation of dimethyl ether (DME) comparison with diethyl ether (DEE) and diisopropyl ether (DIPE), Michie Naito, Claire Radcliffe, Yuji Wada, Takashi Hoshino, Xiongmin Liu, Mitsuru Arai, Masamitsu Tamura. Journal of Loss Prevention in the Process Industries, Volume 18, Issues 4–6, July–November 2005, Pages 469–473 [https://doi.org/10.1016/j.jlp.2005.07.001 DOI] Dimethyl ether is also relatively non-toxic, although it is highly flammable. On July 28, 1948, a BASF factory in Ludwigshafen suffered an explosion after 30 tonnes of dimethyl ether leaked from a tank and ignited in the air. 200 people died, and a third of the industrial plant was destroyed.[https://www.filmothek.bundesarchiv.de/video/583599?topic=doc70ohy4pxya038cw67f7&start=00%3A01%3A01.20&end=00%3A02%3A00.19 Welt im Film 167/1948] {{Webarchive|url=https://web.archive.org/web/20210129152538/https://www.filmothek.bundesarchiv.de/video/583599?topic=doc70ohy4pxya038cw67f7&start=00%3A01%3A01.20&end=00%3A02%3A00.19 |date=2021-01-29 }}. filmothek.bundesarchiv.de

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• Methanol economy

{{Reflist}}

• {{usurped|1=[https://web.archive.org/web/20101126124645/http://aboutdme.org/ The International DME Association]}}
• [https://cameochemicals.noaa.gov/chemical/585 NOAA site for NFPA 704]
• [http://www.xtlinstitute.com/ XTL & DME Institute]

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Category:Aerosol propellants

Category:Dialkyl ethers

Category:Fuels

Category:Synthetic fuels

Category:Symmetrical ethers

Category:Organic compounds with 2 carbon atoms

Category:Substances discovered in the 19th century