Macro-TGA steam-assisted gasification of lignocellulosic wastes

FERNANDEZ, ANABEL; SORIA, JOSÉ; RODRIGUEZ, ROSA; BAEYENS, JAN; MAZZA, GERMÁN

JOURNAL OF ENVIRONMENTAL MANAGEMENT

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Año: 2019 vol. 233 p. 626 - 635

0301-4797

The kinetics of the steam-assisted gasification for three different agro-industrial solid wastes (sawdust, olive and plum pits) was studied by macro thermo-gravimetric analysis (macro-TGA) at different heating rates (5, 10 and 15 K/min). The progressive CO release was moreover monitored to fully identify each step of the global gasification process. A single-step kinetics modelling was applied by using the Coats-Redfern method, with both a first order model for pyrolysis and a Ginstling - Brounstein 3D-diffusion model for the gasification stages, respectively. A comparison between macro-TGA and previous TGA results for the same bio-wastes was performed. Results indicated that the reaction proceeds in three well-defined and subsequent stages, involving water evaporation [298?473 K], biomass de-volatilization [473?648 K] with the highest production of CO, and char gasification as final step. Reaction rate parameters of the Arrhenius equation were determined for both the pyrolysis and gasification steps.