DME作为燃料添加剂

DME as fuel additiveDimethyl ether (DME) has been increasingly used as a propellant in aerosol formulations to replace chlorofluorocarbons, which are found to destroy the ozone layer of the atmosphere. DME is nontoxic and easily degrades in the troposphere. So DME could become a more widely used propellant in the next five years. Several aerosol-based household products include colognes, hair sprays and dyes, personal care mousses, antiperspirants, and room air fresheners.DME has very promising uses as an ultra-clean transportation fuel as well as a fuel for power generation. DME has a high cetane value of about 55-60 and can be directly and effectively used for DME diesel engines. Burning DME in diesel engines results in a lower NOx with no SOx, thus also contributing to the societal air quality.. DME is an useful intermediate for the preparation of many important chemicals, including methyl sulfate. Dimethyl sulfate is an important commercial commodity as a solvent and also as an electrolyte in high energy density batteries. It may be used directly as a transportation fuel in admixture with methanol or as a fuel additive. In particular, dimethyl ether is shaping up as an ultraclean alternative fuel for diesel engines. The advantages of using DME are ultralow emissions of nitrogen oxides (NOx), reduced engine noise or quiet combustion, practically soot-free or smokeless operation and hence no exhaust aftertreatment, and high diesel thermal efficiency. Dimethyl ether is also an essential intermediate in the synthesis of hydrocarbons from coal or natural gas derived syngas. Lower olefins like ethylene and propylene or higher molecular weight compounds such as gasoline range boiling hydrocarbons are produced from syngas using dimethyl ether as an intermediate. A variety of specialty industrial chemicals such as oxygenates, acetaldehyde, acetic acid, ethylene glycol intermediate like DMET, etc. can be formed using dimethyl ether as a feedstock. DESCRIPTION OF DIMETHYL ETHER (DME)Appearance Achromatous gas which canbe easily ,with specific smell of aether PH value 6-7 Melting point (ºC) -141.5 Relative density(water=1) 0.661(20/4ºC) Boiling point (ºC) -24.9 Vapor density (Kg/m3) 1.917-1.918(298.16k,1 atm) Saturated vapor pressure(KPa) 533.2(20ºC) Heat of combustion(KJ/mol) 1455 Critical temperature (ºC) 128.8 Critical pressure(MPa) 5.33 Octanol-water partition coefficients 0.1 Flash point (ºC) -41.4 (open cup) Upper explosion limited %(V/V) 17.5 Lgnition temperature(ºC) 350 Lower explosion limited %(V/V) 3.5 Solubility Good compatibility, can be mixed with water Alcohol , aether ,etc. Other chemical characteristics Inert, no corrosiveness, weak light when burning Incompatibility Strong oxidant, strong acid, halogen Conditions should be avoided Open flame, high heat Decomposition components CO2 , H2O Standard compliance HG/T 3934-2007 Package:Cylinder OR ISO-TANK