DME (Dimethyl Ether)

Dimethyl ether (DME, CH3OCH3) is an oxygenated, LPG-like fuel evaluated for marine compression-ignition engines. Its cetane number of 55 to 60 exceeds diesel, so it ignites readily and needs little or no engine modification, and combustion produces near-zero soot with low NOx and particulate matter. DME is a gas at ambient conditions and is stored as a liquid under moderate pressure, like LPG, which means pressurized tanks and a sealed fuel system. Lower heating value is about 28 MJ/kg, below diesel, so on-board volume rises. It can be made from methanol dehydration or from syngas, and bio-DME or e-DME lowers its well-to-wake carbon.