Low Temperature Isothermal Pyrolysis of Cellulose

Abstract

By providing continuous weight measurement, thermogravimetry, even for isothermal experiments, offers a major advantage over the classical methods of determining weight-change curves in complex pyrolysis reactions. Thus, even minor weight changes, readily detectable on a continuous record, furnish clues concerning the reaction sequences and indicate conditions under which confirmatory experiments may be undertaken. Unfortunately, such perturbations are frequently ignored, being considered part of the “experimental error” which they often represent in the traditional experiments. This paper illustrates the utility of looking at the minor weight deviations, too large to be random experimental error, in a 1,000-hour isothermal pyrolysis experiment on high purity cellulose paper at 226°C. Resolution of the curve into the minimum number of consecutive and competing reactions required to fit within instrumental accuracy yields previously unrecognized characteristics of the pyrolysis behavior, applicable at other temperatures as well.