Chemistry:Dimethyl ether

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Short description: The simplest ether
Dimethyl ether
Skeletal formula of dimethyl ether with all implicit hydrogens shown
Ball and stick model of dimethyl ether
Preferred IUPAC name
Other names
Dimethyl ether[1]
Dimethyl oxide
Dymel A
Methyl ether
Methyl Oxide
Wood ether
3D model (JSmol)
Abbreviations DME
EC Number
  • 204-065-8
MeSH Dimethyl+ether
RTECS number
  • PM4780000
UN number 1033
Molar mass 46.069 g·mol−1
Appearance Colorless gas
Odor Ethereal[2]
Density 2.1146 kg/m3 (gas, 0 °C, 1013 mbar)[2]
0.735 g/mL (liquid, -25 °C)[2]
Melting point −141 °C; −222 °F; 132 K
Boiling point −24 °C; −11 °F; 249 K
71 g/L (at 20 °C (68 °F))
log P 0.022
Vapor pressure 592.8 KPa @ 25°C [3]
-26.3·10−6 cm3/mol
1.30 D
65.57 J K−1 mol−1
−184.1 kJ mol−1
−1.4604 MJ mol−1
Safety data sheet ≥99% Sigma-Aldrich
GHS pictograms GHS02: Flammable GHS04: Compressed Gas
GHS Signal word Danger
HH220Script error: No such module "Preview warning".Category:GHS errors, HH280Script error: No such module "Preview warning".Category:GHS errors
PP210Script error: No such module "Preview warning".Category:GHS errors, PP377Script error: No such module "Preview warning".Category:GHS errors, PP381Script error: No such module "Preview warning".Category:GHS errors, PP403Script error: No such module "Preview warning".Category:GHS errors
NFPA 704 (fire diamond)
Flammability code 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformReactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no codeNFPA 704 four-colored diamond
Flash point −41 °C (−42 °F; 232 K)
350 °C (662 °F; 623 K)
Explosive limits 27%
Related compounds
Related ethers
Diethyl ether

Polyethylene glycol

Related compounds


Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Dimethyl ether (DME; also known as methoxymethane) is the organic compound with the formula CH3OCH3, (sometimes ambiguously simplified to C2H6O as it is an isomer of ethanol). The simplest ether, it is a colorless gas that is a useful precursor to other organic compounds and an aerosol propellant that is currently being demonstrated for use in a variety of fuel applications. It is an isomer of ethanol.


Approximately 50,000 tons were produced in 1985 in Western Europe by dehydration of methanol:[5]

2 CH3OH → (CH3)2O + H2O

The required methanol is obtained from synthesis gas (syngas).[6] 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.[6][7] 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.[6][8]

From biomass

Dimethyl ether is a synthetic second generation biofuel (BioDME), which can be produced from lignocellulosic biomass.[9] The EU is considering BioDME in its potential biofuel mix in 2030;[10] It can also be made from biogas or methane from animal, food, and agricultural waste,[11][12] or even from shale gas or natural gas.[13]

The Volvo Group is the coordinator for the European Community Seventh Framework Programme project BioDME[14][15] where Chemrec's BioDME pilot plant is based on black liquor gasification in Piteå, Sweden.[16]


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:

CH3OCH3 + SO3(CH3)2SO4

Dimethyl ether can also be converted into acetic acid using carbonylation technology related to the Monsanto acetic acid process:[5]

(CH3)2O + 2 CO + H2O → 2 CH3CO2H

Laboratory reagent and solvent

Dimethyl ether is a low-temperature solvent and extraction agent, applicable to specialised laboratory procedures. Its usefulness is limited by its low boiling point (−23 °C (−9 °F)), but the same property facilitates its removal from reaction mixtures. Dimethyl ether is the precursor to the useful alkylating agent, trimethyloxonium tetrafluoroborate.[17]

Niche applications

A mixture of dimethyl ether and propane is used in some over-the-counter "freeze spray" products to treat warts, by freezing them.[18][19] In this role, it has supplanted halocarbon compounds (Freon).

Dimethyl ether is also a component of certain high temperature "MAP-plus" blowtorch gas blends, supplanting the use of methyl acetylene and propadiene mixtures.[20]

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



Installation of BioDME synthesis towers at Chemrec's pilot facility

A potentially major use of dimethyl ether is as substitute for propane in LPG used as fuel in household and industry.[21] Dimethyl ether can also be used as a blendstock in propane autogas.[22]

It is also a promising fuel in diesel engines,[23] 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.[24] Only moderate modifications are needed to convert a diesel engine to burn dimethyl ether. The simplicity of this short carbon chain compound leads during combustion to very low emissions of particulate matter. 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).[25]

At the European Shell Eco Marathon, an unofficial World Championship for mileage, vehicle running on 100% dimethyl ether drove 589 km/liter (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.[26]

To study the dimethyl ether for the combustion process a chemical kinetic mechanism[27] 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.[28][29]


Unlike other alkyl ethers, dimethyl ether resists autoxidation. Dimethyl ether is also relatively non-toxic, although it is highly flammable. BASF Explosion Disaster on July 28, 1948 in Ludwigshafen was caused by this compound – 200 people died, a third of the industrial plant was destroyed.[30]

Data sheet

Routes to produce dimethyl ether

Routes to dimethyl ether.

Vapor pressure

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Experimental vapor pressures of dimethyl ether[31]

See also


  1. 1.0 1.1 "CHAPTER P-6. Applications to Specific Classes of Compounds". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 703. doi:10.1039/9781849733069-00648. ISBN 978-0-85404-182-4. 
  2. 2.0 2.1 2.2 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  3. "Dimethylether". 19 October 2018. 
  4. GHS: Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  5. 5.0 5.1 Manfred Müller, Ute Hübsch, “Dimethyl Ether” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a08_541
  6. 6.0 6.1 6.2 "CHEMSYSTEMS.COM". 
  7. P.S. Sai Prasad et al., Fuel Processing Technology, 2008, 89, 1281.
  8. "Air Products Technology Offerings". 
  9. "BioDME". 
  10. "Biofuels in the European Union, 2006". 
  11. "Oberon Fuels Brings Production Units Online, Launching the First North American Fuel-grade DME Facilities". 
  12. "Associated Gas Utilization via mini GTL". 
  13. Ogawa, Takashi; Inoue, Norio; Shikada, Tutomu; Inokoshi, Osamu; Ohno, Yotaro (2004). "Direct Dimethyl Ether (DME) synthesis from natural gas". Natural Gas Conversion VII, Proceedings of the 7th Natural Gas Conversion Symposium. Studies in Surface Science and Catalysis. 147. pp. 379–384. doi:10.1016/S0167-2991(04)80081-8. ISBN 9780444515995. 
  14. "Home | Volvo Group". 
  15. "Volvo Group - Driving prosperity through transport solutions". 
  16. Chemrec press release September 9, 2010
  17. T. J. Curphey (1988). "Trimethyloxonium tetrafluoroborate". Organic Syntheses. ; Collective Volume, 6, pp. 1019 
  18. "A Pharmacist's Guide to OTC Therapy: OTC Treatments for Warts". July 2006. 
  19. "Archived copy". 
  20. "Archived copy". 
  21. "IDA Fact Sheet DME/LPG Blends 2010 v1". 
  22. Fleisch, T. H.; Basu, A.; Sills, R. A. (November 2012). "The Status of DME developments in China and beyond, 2012". Journal of Natural Gas Science and Engineering 9: 94–107. doi:10.1016/j.jngse.2012.05.012. Retrieved 2020-11-21. 
  23., Nycomb Chemicals company
  24. "Archived copy".
  25. "Archived copy". , Conference on the Development and Promotion of Environmentally Friendly Heavy Duty Vehicles such as DME Trucks, Washington DC, March 17, 2006
  26. "The Danish Ecocar Team - List of achievements". 
  27. Shrestha, Krishna P.; Eckart, Sven; Elbaz, Ayman M.; Giri, Binod R.; Fritsche, Chris; Seidel, Lars; Roberts, William L.; Krause, Hartmut et al. (2020). "A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NO interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature". Combustion and Flame 218: 57–74. doi:10.1016/j.combustflame.2020.04.016. Retrieved 2020-05-18. 
  28. A history of the frozen meat trade, page 26-28
  29. ASHRAE list of refrigerants
  30. Welt im Film 167/1948 .
  31. Wu, Jiangtao; Liu, Zhigang; Pan, Jiang; Zhao, Xiaoming (2003-11-25). "Vapor Pressure Measurements of Dimethyl Ether from (233 to 399) K". J. Chem. Eng. Data 49: 32–34. doi:10.1021/je0340046. Retrieved 2022-01-07. 

External links