Study of potassium salts on sawdust pyrolysis: Kinetics and thermodynamic parameters using isoconversional and Criado's master plot methods

In this study, the effect of potassium salts on sawdust pyrolysis with respect to kinetics and thermodynamic parameters was investigated. Kinetic triplet (activation energy, pre-exponential factor, and reaction mechanism) and thermodynamic properties (enthalpy change, entropy change, and Gibbs free energy) were determined using isoconversional and Criado's master plot methods, respectively. Thermogravimetric analysis (TGA) was carried out in N₂ environment at 5, 25, and 50°C/min from 30 to 800°C. A series of analytical techniques were utilized to fully characterize the raw materials. Analysis of TGA data was performed using isoconversional model. The results suggested that the addition of potassium carbonate showed catalytic effect on the thermal degradation of sawdust by affecting the kinetic triplets and thermodynamic properties. However, the presence of potassium chloride in sawdust pyrolysis is a complex and either promoting or deterring effect was primarily dependent on the degree of conversion.