Gegenüberstellung verschiedener lösungsverfahren zur ermittlung kinetischer parameter anhand von experimentalwerten

The kinetic parameters have been calculated by the differential method according to Freeman and Caroll, the modified differential method, and the integral method according to Coats and Redfern. The calculations have been performed on the base of thermogravimetric data obtained on the recording vacuum thermoanalyzer TA 1 (Mettler). The automatic processing of measured values for off-line operation was carried out by means of data transfer (Mettler) using the small computer KRS 4200. Information on the system and the accuracy of data transfer is given.The methods have been compared for the dehydration of calcium oxalate, the formation of metakaolinite, the oxidation of petroleum coke, and the dehydration of montmorillonite. Using the differential method, in part, kinetic parameters have been obtained which cannot be interpreted in a physical sense. In order to determine the causes of different results, the effects of various mathematical procedures have been studied. This study and the comparison with literature data indicate that the programme for the determination of kinetic parameters by the integral method as described gives the most reliable results.