Macro-TGA steam-assisted gasification of lignocellulosic wastes

• Published in: Journal of environmental management Vol. 233; pp. 626 - 635
• Main Authors: Fernandez, Anabel, Soria, José, Rodriguez, Rosa, Baeyens, Jan, Mazza, Germán
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2019
• Subjects: CO release; Kinetics; Lignocellulosic biomass; Macro-TGA; Steam-assisted gasification; Kinetics; Lignocellulosic biomass; CO release; Macro-TGA; Steam-assisted gasification
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2018.12.087

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. •Gasification of biowastes is studied by macro-TGA analysis and Coast Redfern method.•Pyrolysis stage is well represented by a first-order model.•Gasification stage can be fitted by means of the Ginstling - Brounstein model.•Comparison with previous pyrolysis results is discussed.•CO release during thermal degradation is analyzed.