Torrefaction for the Pyrolysis of Industrial Kraft Lignin: Physicochemical Characterization and Kinetic Triplet Determination

• Published in: Bioenergy research Vol. 17; no. 1; pp. 434 - 451
• Main Authors: Menezes, A. L., Silva, A. C. R., Santana Júnior, J. A., Ataíde, C. H., Cerqueira, D. A., Sousa, N. G., Cardoso, C. R., Vieira, L. G. M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2024; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Decomposition; Decomposition reactions; Drying; Enthalpy; Free energy; Gibbs free energy; Kinetic equations; Kinetics; Life Sciences; Lignin; Plant Breeding/Biotechnology; Plant Ecology; Plant Genetics and Genomics; Plant Sciences; Pyrolysis; Thermodynamic properties; Three dimensional models; Wood Science & Technology; Kinetic simulation; Residual biomass; Activation energy; Reaction model
• ISSN: 1939-1242; 1939-1234; 1939-1242
• DOI: 10.1007/s12155-023-10684-6

The present work aimed to determine the physicochemical characterization and the kinetic and thermodynamic parameters for the pyrolysis of raw and torrefied lignin at 493, 533, and 573 K. The physicochemical and thermal characterization results of the lignin samples demonstrated consistent characteristics for the pyrolysis process. The master plots methods showed that the second-order reaction model (N2) represented the decomposition kinetics of raw and torrefied lignin at 493 and 533 K, and the three-dimensional Ginstling–Brounshtein model (D4) represented the decomposition kinetics of the torrefied lignin at 573 K. The activation energy ( E a ) for raw and torrefied lignin at 493, 533, and 573 K were 106.05, 130.91, 137.20, and 176.81 kJ mol −1 , respectively. The Arrhenius pre-exponential factor ( A ) for raw and torrefied lignin at 493, 533, and 573 K were 3.64×10 6 , 3.10×10 8 , 4.10×10 8 , and 4.64×10 8 s −1 , respectively. The enthalpy variation ( ΔH ), Gibbs free energy ( ΔG ), and entropy ( ΔS ) results for 5, 15, and 25 K min −1 ranged from 100.50 to 142.90, from 162.14 to 181.63, and from −103.99 to −45.21, respectively. The kinetic equation determined for the studied materials was useful for pyrolysis simulation.