Combustion reaction kinetics of guarana seed residue applying isoconversional methods and consecutive reaction scheme
Fernanda Cristina Rezende Lopes1, Katia Tannous1, Yesid Javier Rueda-Ordóñez1
1School of Chemical Engineering, University of Campinas, 500 Albert Einstein Avenue, Campinas, SP 13083-852, Brazil.
Abstract:
This work aims the study of decomposition kinetics of guarana seed residue using thermogravimetric analyzer under synthetic air atmosphere applying heating rates of 5, 10, and 15°C/min, from room temperature to 900°C. Three thermal decomposition stages were identified: dehydration (25.1-160°C), oxidative pyrolysis (240-370°C), and combustion (350-650°C). The activation energies, reaction model, and pre-exponential factor were determined through four isoconversional methods, master plots, and linearization of the conversion rate equation, respectively. A scheme of two-consecutive reactions was applied validating the kinetic parameters of first-order reaction and two-dimensional diffusion models for the oxidative pyrolysis stage (149.57kJ/mol, 6.97×10(10)1/s) and for combustion stage (77.98kJ/mol, 98.611/s), respectively. The comparison between theoretical and experimental conversion and conversion rate showed good agreement with average deviation lower than 2%, indicating that these results could be used for modeling of guarana seed residue.
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