A Round-Robin Study of Cellulose Pyrolysis Kinetics by Thermogravimetry

Abstract

Eight European laboratories with access to five different thermogravimetric analyzers participated in this round-robin study of Avicel PH-105 cellulose pyrolysis at 5 and 40 °C/min. Agreement between the laboratories on the temperature (Tpeak) associated with the maximum rate of weight loss at 5 °C/min was good. Less agreement was obtained on the residual char yield. At 40 °C/min, the scatter associated with measurements of Tpeak and the char yield increased. Good fits to each weight loss curve were obtained by use of a kinetic model based on an irreversible, first-order reaction with a high (ca. 244 kJ/mol) apparent activation energy (E). Variations in values of E and the preexponential constant (A) are attributed to variations in thermal lag between the various instruments and at different heating rates. Kinetic parameters are presented which offer a good fit to the 5 °C/min round-robin data and which prescribe an envelope that contains the data. We recommend that future studies of biomass pyrolysis by thermogravimetry include an analysis of Avicel PH 105 cellulose at 5 °C/min and a comparison of the resulting weight loss curve with the curves presented herein.