Thermodynamic Analysis for the Oxidation of Dimethyl Ether

The standard enthalpy of formation and thermal capacity of dimethoxymethane(DMM) and 1,2-dimethoxyethane(DMET)as a result of dimethyl ether(DME) oxidation were calculated by Benson group contribution.The molar enthalpy changes,the Gibbs free energies and the equilibrium constants of the selective oxidation and total oxidation of DME were calculated as a function of temperature.The effect of pressure and the DME/O2 molar ratio in source gas on DME equilibrium conversion were calculated as well,and the results were compared with the experimental data from the selective oxidation of DME over VOx-SnO2/MgO catalyst.This provides a thermodynamic basis for the synthesis of high added-value products such as DMM and DMET from DMEr and for the total oxidation,namely catalytic combustion,of DME.