A Kinetics Study of Methanol Dehydration to Dimethyl Ether and Catalyst Deactivation over γ-Al2O3
Volume Title: 1
1Catalyst Research Group, Petrochemical Research and Technology Company, National Petrochemical Company, Tehran, Iran.
2head of catalyst group
The deactivation of γ-alumina catalyst in dehydration of methanol to dimethyl ether (DME) was studied using integral method of analysis. Catalytic test runs were performed in a fixed-bed integral reactor in the temperature range of 250-300 ºC. A power-law rate expression was used for dehydration reaction and an independent kinetics for catalyst deactivation. Favorable fit was observed for experimental conversion-time data with an order of deactivation of unity. The activation energies of main reaction and catalyst deactivation were obtained as 96 and 69 kJ/mol, respectively, implying that the former is more sensitive to temperature rise. Never-the-less, the temperature-time trajectory strategy could not be applied for compensating catalyst deactivation with time because of increasing thermodynamic limitation for this exothermic equilibrium-limited reaction.