Names | |||
---|---|---|---|
Preferred IUPAC name Methoxymethane [1] | |||
Other names | |||
Identifiers | |||
3D model (JSmol) | |||
Abbreviations | DME | ||
1730743 | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.003.696 | ||
EC Number |
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KEGG | |||
MeSH | Dimethyl+ether | ||
PubChem CID | |||
RTECS number |
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UNII | |||
UN number | 1033 | ||
CompTox Dashboard (EPA) | |||
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Properties | |||
C2H6O | |||
Molar mass | 46.069 g·mol−1 | ||
Appearance | Colorless gas | ||
Odor | Ethereal [2] | ||
Density | 2.1146 kg m−3 (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 [3] | ||
−26.3×10−6 cm3 mol−1 | |||
1.30 D | |||
Thermochemistry | |||
Heat capacity (C) | 65.57 J K−1 mol−1 | ||
Std enthalpy of formation (ΔfH⦵298) | −184.1 kJ mol−1 | ||
Std enthalpy of combustion (ΔcH⦵298) | −1460.4 kJ mol−1 | ||
Hazards | |||
GHS labelling: [4] | |||
Danger | |||
H220 | |||
P210, P377, P381, P403 | |||
NFPA 704 (fire diamond) | |||
Flash point | −41 °C (−42 °F; 232 K) | ||
350 °C (662 °F; 623 K) | |||
Explosive limits | 27 % | ||
Safety data sheet (SDS) | ≥99% Sigma-Aldrich | ||
Related compounds | |||
Related ethers | Diethyl ether | ||
Related compounds | Ethanol | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
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.
Dimethyl ether was first synthesised by Jean-Baptiste Dumas and Eugene Péligot in 1835 by distillation of methanol and sulfuric acid. [5]
Approximately 50,000 tons were produced in 1985 in Western Europe by dehydration of methanol: [6]
The required methanol is obtained from synthesis gas (syngas). [7] 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. [7] [8] 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. [7] [9]
Dimethyl ether is a synthetic second generation biofuel (BioDME), which can be produced from lignocellulosic biomass. [10] The EU is considering BioDME in its potential biofuel mix in 2030; [11] It can also be made from biogas or methane from animal, food, and agricultural waste, [12] [13] or even from shale gas or natural gas. [14]
The Volvo Group is the coordinator for the European Community Seventh Framework Programme project BioDME [15] [16] where Chemrec's BioDME pilot plant is based on black liquor gasification in Piteå, Sweden. [17]
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:
Dimethyl ether can also be converted into acetic acid using carbonylation technology related to the Monsanto acetic acid process: [6]
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. [18]
A mixture of dimethyl ether and propane is used in some over-the-counter "freeze spray" products to treat warts by freezing them. [19] [20] 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. [21]
Dimethyl ether is also used as a propellant in aerosol products. Such products include hair spray, bug spray and some aerosol glue products.
A potentially major use of dimethyl ether is as substitute for propane in LPG used as fuel in household and industry. [22] Dimethyl ether can also be used as a blendstock in propane autogas. [23]
It is also a promising fuel in diesel engines, [24] 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. [25] 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). [26]
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. [27]
To study the dimethyl ether for the combustion process a chemical kinetic mechanism [28] 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. [29] [30]
Unlike other alkyl ethers, dimethyl ether resists autoxidation. [31] 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. [32]
Temperature (K) | Pressure (kPa) |
---|---|
233.128 | 54.61 |
238.126 | 68.49 |
243.157 | 85.57 |
248.152 | 105.59 |
253.152 | 129.42 |
258.16 | 157.53 |
263.16 | 190.44 |
268.161 | 228.48 |
273.153 | 272.17 |
278.145 | 321.87 |
283.16 | 378.66 |
288.174 | 443.57 |
293.161 | 515.53 |
298.172 | 596.21 |
303.16 | 687.37 |
305.16 | 726.26 |
308.158 | 787.07 |
313.156 | 897.59 |
316.154 | 968.55 |
318.158 | 1018.91 |
323.148 | 1152.35 |
328.149 | 1298.23 |
333.157 | 1457.5 |
333.159 | 1457.76 |
338.154 | 1631.01 |
343.147 | 1818.8 |
348.147 | 2022.45 |
353.146 | 2242.74 |
353.158 | 2243.07 |
358.145 | 2479.92 |
363.148 | 2735.67 |
368.158 | 3010.81 |
373.154 | 3305.67 |
378.15 | 3622.6 |
383.143 | 3962.25 |
388.155 | 4331.48 |
393.158 | 4725.02 |
398.157 | 5146.82 |
400.378 | 5355.8 |
Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colorless, odorless gas. It is the simplest alkane with a tertiary carbon atom. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.
Biodiesel is a renewable biofuel, a form of diesel fuel, derived from biological sources like vegetable oils, animal fats, or recycled greases, and consisting of long-chain fatty acid esters. It is typically made from fats.
Liquefied petroleum gas, also referred to as liquid petroleum gas, is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, n-butane and isobutane. It can sometimes contain some propylene, butylene, and isobutene.
Methyl tert-butyl ether (MTBE), also known as tert-butyl methyl ether, is an organic compound with a structural formula (CH3)3COCH3. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. Primarily used as a fuel additive, MTBE is blended into gasoline to increase its octane rating and knock resistance, and reduce unwanted emissions.
A refrigerant is a working fluid used in cooling, heating or reverse cooling and heating of air conditioning systems and heat pumps where they undergo a repeated phase transition from a liquid to a gas and back again. Refrigerants are heavily regulated because of their toxicity and flammability and the contribution of CFC and HCFC refrigerants to ozone depletion and that of HFC refrigerants to climate change.
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The methanol economy is a suggested future economy in which methanol and dimethyl ether replace fossil fuels as a means of energy storage, ground transportation fuel, and raw material for synthetic hydrocarbons and their products. It offers an alternative to the proposed hydrogen economy or ethanol economy, although these concepts are not exclusive. Methanol can be produced from a variety of sources including fossil fuels as well as agricultural products and municipal waste, wood and varied biomass. It can also be made from chemical recycling of carbon dioxide.
Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis. Me2SO4 is a colourless oily liquid with a slight onion-like odour. Like all strong alkylating agents, Me2SO4 is toxic. Its use as a laboratory reagent has been superseded to some extent by methyl triflate, CF3SO3CH3, the methyl ester of trifluoromethanesulfonic acid.
Gas to liquids (GTL) is a refinery process to convert natural gas or other gaseous hydrocarbons into longer-chain hydrocarbons, such as gasoline or diesel fuel. Methane-rich gases are converted into liquid synthetic fuels. Two general strategies exist: (i) direct partial combustion of methane to methanol and (ii) Fischer–Tropsch-like processes that convert carbon monoxide and hydrogen into hydrocarbons. Strategy ii is followed by diverse methods to convert the hydrogen-carbon monoxide mixtures to liquids. Direct partial combustion has been demonstrated in nature but not replicated commercially. Technologies reliant on partial combustion have been commercialized mainly in regions where natural gas is inexpensive.
In industrial chemistry, black liquor is the by-product from the kraft process when digesting pulpwood into paper pulp removing lignin, hemicelluloses and other extractives from the wood to free the cellulose fibers.
Various alcohols are used as fuel for internal combustion engines. The first four aliphatic alcohols are of interest as fuels because they can be synthesized chemically or biologically, and they have characteristics which allow them to be used in internal combustion engines. The general chemical formula for alcohol fuel is CnH2n+1OH.
In organic chemistry, a carbonate ester is an ester of carbonic acid. This functional group consists of a carbonyl group flanked by two alkoxy groups. The general structure of these carbonates is R−O−C(=O)−O−R' and they are related to esters, ethers and also to the inorganic carbonates.
An alternative fuel vehicle is a motor vehicle that runs on alternative fuel rather than traditional petroleum fuels. The term also refers to any technology powering an engine that does not solely involve petroleum. Because of a combination of factors, such as environmental and health concerns including climate change and air pollution, high oil-prices and the potential for peak oil, development of cleaner alternative fuels and advanced power systems for vehicles has become a high priority for many governments and vehicle manufacturers around the world.
Natural refrigerants are considered substances that serve as refrigerants in refrigeration systems. They are alternatives to synthetic refrigerants such as chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), and hydrofluorocarbon (HFC) based refrigerants. Unlike other refrigerants, natural refrigerants can be found in nature and are commercially available thanks to physical industrial processes like fractional distillation, chemical reactions such as Haber process and spin-off gases. The most prominent of these include various natural hydrocarbons, carbon dioxide, ammonia, and water. Natural refrigerants are preferred actually in new equipment to their synthetic counterparts for their presumption of higher degrees of sustainability. With the current technologies available, almost 75 percent of the refrigeration and air conditioning sector has the potential to be converted to natural refrigerants.
Second-generation biofuels, also known as advanced biofuels, are fuels that can be manufactured from various types of non-food biomass. Biomass in this context means plant materials and animal waste used especially as a source of fuel.
1,1-Dichloro-1-fluoroethane is a haloalkane with the formula C
2H
3Cl
2F. It is one of the three isomers of dichlorofluoroethane. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment.
Carbon-neutral fuel is fuel which produces no net-greenhouse gas emissions or carbon footprint. In practice, this usually means fuels that are made using carbon dioxide (CO2) as a feedstock. Proposed carbon-neutral fuels can broadly be grouped into synthetic fuels, which are made by chemically hydrogenating carbon dioxide, and biofuels, which are produced using natural CO2-consuming processes like photosynthesis.
Syngas to gasoline plus (STG+) is a thermochemical process to convert natural gas, other gaseous hydrocarbons or gasified biomass into drop-in fuels, such as gasoline, diesel fuel or jet fuel, and organic solvents.
Polyoxymethylene dimethyl ethers (PODE or DMMn) are a class of chemical compounds with the molecular formula H3CO(CH2O)nCH3 where n is typically about 3 to 8.
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