Synthesis of Dimethyl Ether from Supercritical Methanol in the Presence of Aluminum

A novel method to synthesize dimethyl ether (DME) is presented. When methanol is treated with aluminum metal in supercritical conditions at a density of 0.39 kg/dm^3, it is found that DME is generated above 275 °C through a single-step procedure. The DME production increases with the temperature elevation, and it becomes the main product above 300 °C with by-products of hydrogen and methane. DME is considered to be produced at the formation step of methyl derivative of boehmite and/or its surface catalytic effect.