Examination of the effect of temperature, biomass characteristics, and heating rates on volatile release yield in palm kernel shell pyrolysis using volatile state kinetic modeling

Abstract

The behavior of biomass pyrolysis can be predicted by analyzing its characteristics. This study aimed to model the release of volatiles across various temperatures, biomass properties, and heating rates. Palm kernel shells were pyrolyzed at 433–773 K with a heating rate of 5 K·min⁻¹ using volatile-state kinetic modeling. The process began by calculating the biomass type number (N_CT), which was used to determine volatile enhancement (V_E), volatile release yield (Y_VY), product yield (Y_i), and product mass fraction (y_i). The kinetic parameters, including the activation energy for product formation (E_ai), were derived through a fitting process.

The results indicate a Y_VY of 70.77% within the devolatilization zone, corresponding to the degradation of cellulose and hemicellulose. The Y_VY increased with higher temperatures, lower N_CT, and higher heating rates. The activation energy ranged from 155–185 kJ·mol⁻¹ for biocrude oil (BCO) and 149–186 kJ·mol⁻¹ for gas. The kinetic parameters from the volatile-state kinetic model demonstrated errors below 0.2% in comparison with the experimental data, confirming the model's accuracy and reliability.