Thermogravimetric analysis of biomass. Devolatilization studies on feedlot manure

The devolatilization reactions of feedlot manure were studied by means of a thermogravimetric analyzer. The effects of size fraction, heating rate, and purge gas rate on the thermogram characteristics, such as the total weight percent devolatilized and the temperature at which the maximum rate of weight loss occurred, were analyzed statistically. The results indicated that the total weight percent devolatilized was mainly influenced by the size fraction, while the temperature at which the maximum rate of devolatilization occurred was mainly affected by the heating rate. The devolatization data were fitted to a multireaction model, and the kinetic parameters were determined. The parameters E/sub m/, the mean value of the activation energy, and /delta/, the standard deviation of the activation energy, were analyzed statistically to assess their dependence on the heating rate, size fraction, and purge gas rate. 15 refs.