Chemical and physical characteristics of DMEWhereas methanol is the simplest alcohol, DME is the simplest ether. DME’s physical properties are similar to those of liquefied petroleum gases (i.e., propane and butane). Gaseous in ambient conditions, DME becomes a liquid when cooled to -25C or pressurized to about six atmospheres. DME comprises two carbons, six hydrogens, and one oxygen. A hydrogen-rich compound, DME contains no direct carbon bonds or sulfur, which makes it ultra-clean burning.
Conventionally made from fossil fuels (natural gas and coal), DME can also be produced from renewable materials (biomass, waste — and renewable electricity and carbon dioxide).
Until recently DME was primarily used as an ozone-friendly aerosol propellant and in the production of ultra-pure glass. Today, DME is a promising transportation fuels because of its many significant benefits:
- Ultra-low exhaust emissions
- No particulate matter (PM); very low NOx; no Sox)
- Low engine noise
- High fuel economy
- High well-to-wheel efficiency
- Engine thermal efficiency equal to or better than diesel fuel
DME can be used in diesel engines without engine modification, but with minor modifications to the fuel supply and lubrications. Blended with propane (30% DME/70% propane), it can also be used in gasoline engines. Other prominent uses for DME include: fuel for gas turbines for power generation, without modification to turbines or combustors; and propane blendstock (20% DME/80% propane) for cooking and heating, without equipment modifications.