Experimental study and modeling of biomass char gasification kinetics in a novel thermogravimetric flow reactor

摘要

This work pursues the validation of a new reactor for the evaluation of char gasification kinetics. This novel reactor allows continuous gas flow through the fixed bed sample and accurately monitoring the mass loss throughout the reaction. Accordingly, this thermogravimetric flow reactor has a great potential for the analysis of different thermochemical processes, such as pyrolysis and gasification of solid feedstocks. In this paper, the gasification of pine sawdust char was carried out and the effect carbon dioxide concentration (10 and 100 vol%) and temperature (800, 850 and 900 degrees C) have on char gasification kinetics was assessed. The experimental results were fitted to five different kinetic equations, i.e., homogeneous model (VM), shrinking core model (SCM), nth order model, random pore model (RPM) and modified random pore model (MRPM), and the best-fit parameters (frequency factor, activation energy, adjustable parameters and fitting error) were obtained for each model. The modified random pore model provides the best fit to the experimental data. The new thermogravimetric flow reactor allows obtaining rigorous kinetic results, which is clear evidence that the reactor is suitable for studying char gasification kinetics under CO2 atmosphere.