Pyrolysis of ficus nitida wood: Determination of kinetic and thermodynamic parameters

In the present work, the kinetic and thermodynamic analysis of ficus wood was carried out using the thermogravimetric analysis (TGA). Thermal degradation of ficus wood has been evaluated under dynamic conditions from 373 K to 1173 K at heating rates of 5, 10, 20, and 50 K.min(-1). The kinetic analysis was performed using isoconversional methods (Friedman (FR), Flynn-Wall-Ozawa (FWO) and Vyazovkin (VYA)) and the integral master-plots method to estimate the kinetic triplets. The thermogravimetric and kinetic data were used to calculate the thermodynamic parameters (Delta G, Delta H and Delta S) and kinetic compensation effects. The conversion range of 0.05 <= x <= 0.9 shows clearly that the pyrolysis of ficus wood could represent a triple-step reaction, which corresponds to the pyrolysis of hemicellulose, cellulose, and lignin, respectively. From the isoconversional plots of ficus wood having average activation energy values of 171.4-180.3 kJ.mol(-1), 206.48-214.42 kJ.mol(-1) and 237.85-248.23 kJ.mol(-1) for hemicellulose, hemicellulose, and lignin, respectively. The experimental data of focus wood had overlapped the D4, D2, and F3 in the conversion range of 5-35%, 35-75%, and 75-90%, respectively. All values of Delta H and Delta G maintain at a positive constant, whereas the value of Delta S is negative in the range of 5-35%. The difference between E-values and the Delta H value for the three pseudo-components of ficus wood is about approximate to 5 kJ.mol(-1). The kinetic and thermodynamic parameters will be beneficial in assimilating the thermal decomposition of ficus wood for its use in bioenergy.

Automated summary

In this study, the kinetic and thermodynamic analysis of ficus wood was conducted using thermogravimetric analysis, revealing a triple-step reaction corresponding to the pyrolysis of hemicellulose, cellulose, and lignin. The experimental data provided insight into the activation energy and thermodynamic parameters for each step, offering valuable information for the utilization of ficus wood in bioenergy applications.