Print: | ISSN 0256-1115 |
Online: | ISSN 1975-7220 |
Korean Journal of Chemical Engineering,
Vol.12, No.2, 251-257, 1995 TEMPERATURE PROGRAMMED DESORPTION TECHNIQUE TO PREDICT THE CARBON OXYGEN REACTION
The kinetics of the reaction of oxygen with a sucrose char particle size : (88㎛<dp<1에㎛) has been studied using a thermogravimetric analyzer (TGA) and a mass spectrometer (MS) to measure weight change and CO and CO2 formation rates during reaction. Experiments were performed to determine the surface oxide formation rate and to determine the mechanism of CO desorption in the temperature range of 762K to 851K and for oxygen pressures of 0.04 to 0.3 atm, respectively. When the reaction rate at 30% conversion was used in the Arrhenius plot, an activation energy of 34±3kcal/mol was obtained and the CO/CO2 ratio was found to increase with increasing reaction temperature. Analysis of the rate of formation of CO and CO2 shows the activation energy for CO formation is greater than for CO2 formation. Temperature programmed desorption (TPD) studies of the surface oxides were made to provide a better understanding of the carbon oxidation process. The activation energy distribution function for desorption was approximately Gaussian and the average activation energy is 55 Kcal/mol for a preexponential factor of 1013 1/sec. The peak of the energy distribution function shifts to higher activation energies for surface complexes formed at higher reaction temperature.
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