Dimethyl ether

	Email		Print
	Bookmark		Link

Dimethyl ether

Dimethyl ether is the organic compound

Organic compound

An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered Inorganic compound....
with the formula CH₃OCH₃. The simplest ether

Ether

Ether is a class of organic compounds which contain an ether functional group ? an oxygen atom connected to two alkyl or aryl groups ? of general formula R?O?R....
, it is a colourless gas that is a useful precursor to other organic compounds and an aerosol propellant. Dimethyl ether is also promising as a clean-burning hydrocarbon fuel.

thyl ether is produced by the dehydration of methanol

Methanol

Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a chemical compound with chemical formula carbonhydrogen3oxygenhydrogen ....
:

2 CH₃OH ? CH₃OCH₃ + H₂O

Approximately 50,000 tons were produced in 1985 in Western Europe alone.

Discussion

Ask a question about 'Dimethyl ether'

Start a new discussion about 'Dimethyl ether'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Dimethyl ether is the organic compound

Organic compound

Ether

Production

Dimethyl ether is produced by the dehydration of methanol

Methanol

Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a chemical compound with chemical formula carbonhydrogen3oxygenhydrogen ....
:

2 CH₃OH ? CH₃OCH₃ + H₂O

Approximately 50,000 tons were produced in 1985 in Western Europe alone. In principle, it could also be manufactured by partial hydrogenation

Hydrogenation

Hydrogenation is the chemical reaction that results from the addition of hydrogen . The process is usually employed to a redox or Saturation organic compounds....
of carbon monoxide

Carbon monoxide

Carbon monoxide, with the chemical formula CO, is a colorless and odorless, tasteless, yet highly toxic gas. Its molecules consist of one carbon atom covalent bond to one oxygen atom....
, which in turn can be obtained from many sources of hydrocarbons, including biomass

Biomass

Biomass, as a renewable energy source, refers to living and recently dead biological material that can be used as fuel or for industrial production....
.

Applications

Dimethyl ether has two primary applications: as a propellent in aerosol cannisters

Aerosol spray

Aerosol spray is a type of dispensing system which creates an Particulate mist of liquid particles. This is used with a spray can or bottle that contains a liquid under pressure....
, and as a precursor to dimethyl sulfate

Dimethyl sulfate

Dimethyl sulfate is a chemical compound with chemical formula 2SO2. As the dimethyl ester of sulfuric acid, its formula is often written as 2Sulfate or even Me2SO4, where CH3 or Me is methyl....
. As an aerosol propellent, dimethyl ether is useful as a somewhat polar solvent.

Feedstock

Several thousand tons of dimethyl ether are consumed annually for the production of the methylating agent, dimethyl sulfate

Dimethyl sulfate

Sulfur trioxide

Sulfur trioxide is the chemical compound with the formula SO3. In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain....
:

CH₃OCH₃ + SO₃ ? (CH₃O)₂SO₂

This compound is also converted to acetic acid

Acetic acid

Acetic acid, CH3COOH, also known as ethanoic acid, is an organic acid which gives vinegar its sour taste and pungent smell. Pure, water-free acetic acid is a colourless liquid that absorbs water from the environment , and freezes at 16.7 Celsius to a colourless crystalline solid....
using technology related to the Monsanto acetic acid process:

(CH₃)₂O + 2 CO + H₂O ? 2 CH₃CO₂H

Laboratory reagent and solvent

Dimethyl ether is a low-temperature solvent and extraction agent that is used as a solvent in specialised laboratory procedures. Its usefulness is limited by its low boiling point

Boiling point

The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid....
(−23 °C), but the same property facilitates its removal from reaction mixtures. Dimethyl ether is the precursor to the useful alkylating agent, trimethyloxonium tetrafluoroborate.

Fuel

DME is a promising fuel in diesel engines, petrol engine

Petrol engine

A Petrol engine or Gasoline engine is an internal combustion engine with spark-ignition engine designed to run on petrol and similar volatile fuels....
s (30% DME / 70% LPG), and gas turbines owing to its high cetane number

Cetane number

Cetane number or CN is a measurement of the combustion quality of diesel fuel during compression ignition. It is a significant expression of diesel fuel quality among a number of other measurements that determine overall diesel fuel quality....
, which is greater than 55 compared to diesel, which is 40–53. Only moderate modification are needed to convert a diesel engine to burn DME. The simplicity of this short carbon chain compound leads during combustion to very low emissions of particulate matter, NO_x, CO. 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). DME is being developed as a synthetic biofuel (BioDME), which can be manufactured from lignocellulosic biomass

Lignocellulosic biomass

Lignocellulosic biomass refers to plant biomass that is composed of cellulose, hemicellulose, and lignin. The carbohydrate polymers are tightly bound to the lignin, by hydrogen and covalent bonds....
. Currently the EU is considering BioDME in its potential biofuel mix in 2030, the Volvo

Volvo

The Volvo Group is a Sweden supplier of commercial vehicles such as trucks, buses and construction equipment, drive systems for marine and industrial applications, aerospace components and financial services....
Group is the coordinator for the European project BioDME. and Mobil

Mobil

Mobil was a major United States Petroleum company which merged with Exxon in 1999 to form ExxonMobil. Today Mobil continues as a major brand name within the combined company....
is using it in their methanol to gasoline process. The image below illustrates some of processes from various raw materials to DME.

Treating warts

A mixture of dimethyl ether and propane

Propane

Propane is a three-carbon alkane, normally a gas, but compressible to a transportable liquid. It is derived from other petroleum products during oil or natural gas processing....
is used in an over-the-counter device to treat warts, by freezing them.

Safety

Unlike other alkyl ethers, it resists autoxidation

Autoxidation

Autoxidation is any oxidation that occurs in open air or in presence of oxygen and/or UV radiation and forms peroxides and hydroperoxides. A classic example of autoxidation is that of simple ethers like diethyl ether, whose peroxides can be dangerously explosive....
. Dimethyl ether is also relatively non-toxic, although it is highly flammable.

Dimethyl ether

Production

Applications

Feedstock

Laboratory reagent and solvent

Fuel

Treating warts

Safety

External links