Kinetics of the Catalytic Thermal Degradation of Sugarcane Residual Biomass Over Rh-Pt/CeO2-SiO2 for Syngas Production

Abstract

Thermochemical processes for biomass conversion are promising to produce renewable hydrogen-rich syngas. In the present study, model fitting methods were used to propose thermal degradation kinetics during catalytic and non-catalytic pyrolysis (in N2) and combustion (in synthetic air) of sugarcane residual biomass. Catalytic processes were performed over a Rh-Pt/CeO2-SiO2 catalyst and the models were proposed based on the Thermogravimetric (TG) analysis, TG coupled to Fourier Transformed Infrared Spectrometry (TG-FTIR) and TG coupled to mass spectrometry (TG-MS). Results showed three different degradation stages and a catalyst effect on product distribution. In pyrolysis, Rh-Pt/CeO2-SiO2 catalyst promoted reforming reactions which increased the presence of H2. Meanwhile, during catalytic combustion, oxidation of the carbon and hydrogen present in biomass favored the release of H2O, CO and CO2. Furthermore, the catalyst decreased the overall activation energies of pyrolysis and combustion from 120.9 and 154.9 kJ mol−1 to 107.0 and 138.0 kJ mol−1, respectively. Considering the positive effect of the Rh-Pt/CeO2-SiO2 catalyst during pyrolysis of sugarcane residual biomass, it could be considered as a potential catalyst to improve the thermal degradation of biomass for syngas production. Moreover, the proposed kinetic parameters are useful to design an appropriate thermochemical unit for H2-rich syngas production as a non-conventional energy technology.