Advanced kinetic-based approach of multistep processes: The case of the pyrolysis of biomass-derived humins

Author(s)

Gariboti, Julio Cesar de Jesus ; Macedo, Marina Gontijo Souza ; Gomes, Eliezer Ladeia ; Rueda-Ordonez, Yesid Javier ; Felisbino, Romilda Fernandez ; Tovar, Laura Plazas

• Document type: Journal article
• Source: JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS; v. 166, p. 15-pg., 2022-07-08.

Abstract

The pyrolysis of sugarcane bagasse derived-humins (H-SCB) was evaluated in this work by considering inde-pendent, overlapping, or competing multistep reactions. An eight-stage parallel reaction model was used in the thermokinetic analysis. The most appropriate kinetic mechanism determined by the master-plot method showed that the second sub-stage proceeds via a 4th-order chemical reaction and the other steps are controlled by nucleation. Based on mathematical calculations, six consecutive-competitive reactions were studied and the modified Kilzer-Broido model was the most relevant to represent the pyrolysis of H-SCB. The kinetics is influ-enced by the reactivity of H-SCB in two parallel n-order reactions (n = 6.28 to volatile compounds and n = 1.35 to intermediate product). Diffusion-controlled reaction governed the secondary stage in the conversion to bio-char. Competitively, nuclei growth occurs and the intermediate product decomposes into volatile products. By using multistep reactions to account for pyrolysis products, the predicted kinetic profiles agreed well with the experimental data. (AU)

• FAPESP's process: 15/20630-4 - Biorefinery development integrated to a bioethanol sugar cane plant with zero CO2 emission: routes to convert renewable resources to bio-products and bio-electricity
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/11347-5 - Thermochemical valorisation of insoluble humins derived from the C5 and C6 sugars conversion platform
• Grantee: Marina Gontijo Souza Macedo
• Support Opportunities: Scholarships in Brazil - Scientific Initiation