This study investigates the pyrolysis behavior and kinetic characteristics of nut shells and eucalyptus wood to understand how structural and compositional differences of the biomass influence product yields. Experimental pyrolysis was conducted across a range of temperatures (200–600 °C), with measured yields of gas, tar, and char used to fit a three-component lumped kinetic model. Results revealed that eucalyptus exhibited rapid devolatilization and higher gas yields at moderate temperatures, while the nut shells demonstrated greater char retention and slower conversion, consistent with their higher lignin content. The fitted kinetic models achieved strong agreement with experimental data (R² > 0.95), and sensitivity analysis confirmed that gas yields are particularly responsive to variations in kinetic parameters. These findings underscore the critical role of biomass type in determining pyrolysis outcomes and provide practical guidance for optimizing biofuel production via thermal conversion routes.
