The new coal chemical industry in China mainly develops from coal to oil, coal to olefin and coal to dimethyl ether. Among them, coal to dimethyl ether has been favored by many enterprises for its unique advantages. With the gradual start-up of plants under construction and the development of DME application technology, DME is expected to develop into the most important alternative fuel in China.

Why has Dimethyl Ether emerged from the crowd? From the global (excluding China) annual production of fewer than 200,000 tons in 2002, it has developed to the current domestic launch of million-ton plants.

What are the advantages of DME and what are the development prospects? What are the opportunities and challenges in China at this stage? The answers will be found in this article.

Dimethyl ether is an organic compound. It is a colorless and odorous flammable gas in its standard state. The chemical formula is C2H6O.

Dimethyl ether has the structural formula CH3OCH3 and the molecular weight is 46.07. Dimethyl ether is a colorless gas or compressed liquid at atmospheric pressure with a slight ether flavor. Melting point -141℃, boiling point -29.5℃. Dimethyl ether is soluble in water and a variety of organic solvents such as alcohol, ether, acetone and chloroform. It is flammable, and the flame is slightly bright when burning. DME is inert at room temperature. It is not easy to oxidize automatically, non-corrosive and non-carcinogenic. However, it can be decomposed into methane, ethane, formaldehyde, etc. under radiation or heating conditions.

Dimethyl ether is mainly used as a methylating agent to produce dimethyl sulfate. It can also be synthesized as N,N-dimethylaniline, methyl acetate, acetic anhydride and ethylene. It is also used as an alkylating agent, refrigerant, foaming agent, solvent, leaching agent, extractant, anesthetic, fuel, civil compound ethanol and substitute for Freon aerosol. Dimethyl ether is used in hair care, skin care, pharmaceuticals and paints as various types of aerosol propellants. Fuel additives promoted abroad have many unique uses in the pharmaceutical, dye and pesticide industries.

Although DME in the field of vehicle fuel still has not achieved large-scale application, as a civil fuel, DME compared with natural gas and liquefied petroleum gas price advantage is obvious.

Dimethyl ether is a new basic organic chemical raw material. Because of its good compression, condensation, and gasification characteristics, so dimethyl ether in pharmaceutical, fuel, pesticide and other chemical industries has many unique uses.

For example, high purity dimethyl ether can be used instead of Freon as an aerosol spray agent and refrigerant to reduce the pollution of the atmospheric environment and the destruction of the ozone layer. Due to its good water solubility and oil solubility, its application scope is much better than that of propane, butane and other petroleum chemicals.

Instead of methanol, it can be used as a new raw material for formaldehyde production, which can significantly reduce the production cost of formaldehyde. It also shows its superiority in large formaldehyde plants.

As a civil fuel gas, its performance indexes such as storage and transportation, combustion safety, calorific value and theoretical combustion temperature of premixed gas are better than those of LPG. It can be used as peak regulating gas and LPG mixing gas in city pipeline gas.

DME is also an ideal fuel for diesel engines. Compared with methanol fuel vehicles, there is no cold start problem. Dimethyl ether is also one of the main raw materials to produce low-carbon olefin in the future.

Recently, due to the construction of large coal-to-methanol units, China has turned from an importer of methanol to an exporter. This has triggered a price reduction spree of methanol. Since November 2006, the domestic methanol price has fallen from about 4000 yuan/ton to nearly 2000 yuan/ton at present. And there are a large number of methanol projects under construction in China. The potential overcapacity has seriously threatened the profit margin of the whole methanol industry.

Methanol is not only overcapacity but also the development of its applications is difficult. Methanol to Olefin (MTO) is a huge investment and the technology is not mature. For the time being, it does not have the conditions to be promoted on a large scale nationwide.

The application of methanol for vehicle fuel is also basically at a standstill due to immature technology and insurmountable environmental problems. Fortunately, large-scale construction of methanol in DME plants to convert methanol into clean, easy-to-use, high-value-added DME fuel can solve the problem of methanol surplus.

Due to the shortage of oil resources, the abundance of coal resources and the increase in people’s awareness of environmental protection. Dimethyl ether, which is converted from coal into clean fuel, is gaining more and more attention. It has become a carbon monochemical product with superior performance that has been competing for development at home and abroad in recent years.

As an alternative fuel to LPG and petroleum, DME is a chemical with physical properties similar to LPG, and can be produced cheaply and in large quantities without producing environmentally damaging gases during combustion.