KINETICS OF LIQUID PHASE CATALYTIC DEHYDRATION OF METHANOL TO DIMETHYL ETHER

The kinetics of the liquid phase catalytic dehydration of methanol to dimethyl ether were investigated. The experiments were carried out under low concentrations of feed in a 1-L stirred autoclave, according to a statistical experimental design. The inert liquid phase used for this investigation was a 78:22 blend of paraffinic and naphthenic mineral oils. A complete thermodynamic analysis was carried out in order to determine the liquid phase concentrations of the dissolved species. A global kinetic model was developed for the rate of dimethyl ether synthesis in terms of the liquid phase concentration of methanol. The activation energy of the reaction was found to be 18,830 cal/gmol. Based on a step-wise linear regression analysis of the kinetic data, the order of the reaction which gave the best fit was 0.28 with respect to methanol. Effects of the solid to liquid and the gas to liquid mass transfer resistances on the kinetic rate have also been investigated.