Study on biomass fast pyrolysis kinetics in an isothermal spouted-bed thermogravimetric analyzer and its application to CFD

Abstract

In this study, a spouted-bed thermogravimetric analyzer (SB-TGA) was developed to accurately investigate the reaction models and kinetic parameters of the spouted beds. In addition, the analyzer overcomes the disad-vantages of conventional thermogravimetric analyzers that arise from different hydrodynamics. The spouted-bed reactor used in the SB-TGA was scaled down to a small size using dimensional scaling laws, and the hydrody-namic similarity of the reactor to a large-scale reactor was validated. Isothermal experiments using the SB-TGA were performed from 673.15 to 823.15 K. The contracting volume model (R2) was found to suitably represent the pyrolysis reaction of sawdust in a spouted-bed reactor. The activation energy and pre-exponential factor of the global degradation reaction, and the formation rate constants in the same temperature range for tar, char, and gas were determined. The experimental results demonstrated that the SB-TGA provides more reliable results for predicting the pyrolysis reaction by computational fluid dynamic (CFD) in a spouted-bed.