Kinetics of ethanol oxidation in high-pressure steam

Abstract

Ethanol oxidation rate in high pressure steam at the pressure of 10 MPa in the temperature ranging from 430 to 490°C was studied with the fuel equivalence ratio of 0.4. On the assumption that the reaction order is first order, the reaction rate parameters obtained in the experiments are 1011.6 ± 0.4 s-1 for the pre-exponential factor and 166.5 ± 6.1 kJ·mol-1 for the activation energy. This ethanol oxidation rate in high-pressure steam was equivalent to that in supercritical water oxidation of ethanol. Liquid products were acetaldehyde and acetic acid and gas phase products were carbon monoxide, carbon dioxide, methane and ethane. A parallel reaction network of first order model well described the characteristics of the ethanol decomposition to acetaldehyde and acetic acid. Utilisation of the high-pressure steam oxidation process can overcome the problem of pressure tightness of the reactor in supercritical water oxidation, and the process can be employed in practical facilities. © 2011 by JSME.