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Q1 What are DME's basic physical characteristics? |
DME (Dimethyl ether) is a clean, colorless gas that is easy to liquefy and transport. Chemically speaking, DME is the simplest ether compound, with a chemical formula of C2H6O. DME can be derived from many sources, including renewable materials (biomass, including municipal waste and waste from paper and pulp mills, wood, or agricultural products) and fossil fuels (natural gas and coal).
DME has been used for decades in the personal care industry (as an environmentally benign propellant in aerosols), as DME is non-toxic and is easily degraded in the troposphere.
At standard temperature and pressure DME is a gas, but can be liquefied under a moderate pressure. This makes DME quite similar to propane and liquefied petroleum gas for handling purposes. |
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Some physical and chemical characteristics of DME are given below: |
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Chemical formula |
H3C-O-CH3 |
Molecular weight |
46.07 |
Oxygen content by mass |
34.8 % |
CAS Registry number |
115-10-6 |
Boiling point @ 1 atmosphere |
-24.825 °C |
Critical temperature |
126.85 °C |
Critical pressure |
5370 kPa |
Liquid density @ 25 °C |
656.62 kg/m3 |
Vapor pressure @ 20 °C |
516.76 kPa |
Flammability limits in air by volume % |
3.4 – 18 | |
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Q2 How is DME produced? |
DME can be produced from a variety of abundant sources, including natural gas, coal, waste from pulp and paper mills, forest products, agricultural by-products, municipal waste and dedicated fuel crops such as switch grass. World production of DME today stands at approximately 9 million tons per annum, and is primarily by means of methanol de hydration. DME can also be manufactured directly from synthesis gas produced by the gasification of coal or biomass, or through natural gas reforming. Among the various processes for chemical conversion of natural gas, direct synthesis of DME is the most efficient. |
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Q3 Where is DME being produced? |
The majority of global DME production is currently in China. Japan has production facilities, and major new capacity additions are planned or under construction in Trinidad and Tobago, North America, Indonesia, and Uzbekistan. The world's first bioDME plant is in Sweden. |
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Q4 Which companies offer technology related to DME production and use? |
Oberon Fuels offers a skid-mounted modular DME production facility for distributed DME production.
Haldor Topsoe offers DME technology for the production of DME from methanol as well as hydrocarbon feed.
Lurgi offers technology for the production of DME via their MegaDME process. |
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Q5 What benefits does DME offer when blended with LPG? |
DME can be blended with LPG and used for domestic cooking and heating – blends containing up to 20% volume DME generally require no modifications to equipment or distribution networks. Growth in DME’s use for such domestic applications is increasing sharply as DME blending becomes more widespread within the large, and growing, LPG market – in particular in developing countries where portable (bottled) fuel is providing a safer, cleaner, and more environmentally benign fuel for cooking and heating.
DME’s use as an alternative energy source enjoys wide-ranging support in a number of countries, with numerous projects underway or being planned. In developed economies, the demand for “greener” sources of energy has led to interest in blends using DME produced from renewable feedstock (“BioDME”).
IDA Fact Sheet: DME/LPG Blending |
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Q6 What are the benefits of DME's use as a transportation fuel ? |
DME is one of the most promising alternative automotive fuel solutions among the various ultra clean, renewable, and low-carbon fuels under consideration worldwide. DME can be used as fuel in diesel engines, gasoline engines (30% DME / 70% LPG), and gas turbines. Only modest modifications are required to convert a diesel engine to run on DME, and engine and vehicle manufacturers, including Volvo, Mack, Isuzu, Nissan, and Shanghai Diesel have developed heavy vehicles running on diesel engines fueled with DME. It is as a replacement for diesel fuel that DME particularly demonstrates its most distinct advantages.
IDA Fact Sheet: DME as a Transportation Fuel |
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Q7 What health and safety considerations are there with DME? |
Important concerns with any fuel used for transportation or cooking and heating are the potential environmental and human health impacts of the use of the fuel. In the case of DME, there are no concerns with regard to human or animal exposure.
DME was first used as an aerosol propellant because of its environmentally benign characteristics. It is not harmful to the ozone layer, unlike the CFCs that it replaced. DME producer DuPont Fluorochemicals (which markets DME under the product name “Dymel A”), provides a technical bulletin that gives a good overview of the physical and chemical properties of DME, and the results of their own health and safety studies.
"A two-year inhalation study and carcinogenicity bioassay at exposure levels of up to 20,000 ppm showed no compound-related effects..., no signs of carcinogenicity..., and no evidence of mutagenicity or teratogenicity in separate reproductive studies. Based on all these studies, the product have been approved by the Dupont Company for general aerosol use, including in personal products. |
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Q8 Which regulations and standards pertain to DME and its use? |
International standards related to the use of DME are anticipated from the International Organization for Standardization (ISO) in 2015.
Progress towards a single standard for LPG and DME blends is being made, with technical research being conducted by companies involved in the production, blending, and distribution of DME in China, in conjunction with the manufacturers of vales, seals and cylinders. Formal regulations regarding the cylinder, handling, and allowable percentages of DME to be used in such blends are a necessary next step towards further market development, and establishment of internationally-recognized safety and handling procedures. |
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Q9 What are the market indications for DME right now? |
If there is a need for LPG for cooking and domestic (household heating and cooking) uses, then there is a ready market for DME. DME can be produced in Asia at a fairly consistent price as an LPG replacement and as a “clean cooking fuel”, without subjecting consumers to the volatility of LPG price swings (which follow petroleum prices). In China, facilities that make methanol from coal gasification are being converted to DME by adding a methanol dehydration step to the methanol plant. So, there is a market for clean cooking fuel and a price stability benefit for DME.
Another way to view the potential for the DME market is the cost involved in taking conventional diesel technology and making “clean diesel” vehicles. To meet anticipated NOx and PM standards will require substantial additional vehicle costs for higher levels of in-cylinder pollutant control and for exhaust aftertreatment. One could nearly achieve this same emissions level with only a modest amount (or even perhaps none at all) of aftertreatment. So, the net cost may be able the same for a DME vehicle and the consumer appeal could be far better. |
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Q10 What is the price of DME? |
For DME produced from methanol, the price of DME is a function of the price of methanol and LPG. The energy value of DME is approximately 62% that of LPG, however, the listed sale price is typically 75 - 90% that of LPG, representing a premium to energy value. |
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