Chemistry

Materials science

Pyrolysis

Reaction rate constant

Physics

Kinetics

Pyrolytic carbon

Hemicellulose

Cellulose

Lignin

Exothermic reaction

Quantum mechanics

Organic chemistry

Thermogravimetric analysis

Decomposition

Chemical engineering

Activation energy

Order of reaction

Physical chemistry

Engineering

Kinetic energy

Waste Management

This study focuses on the thermo-kinetic analysis of solid peanut shell waste, through dependence of the activation energy with the conversion degree. Three model-free kinetics, Kissinger (K), Friedman (Fr) and Kissinger-Akahira-Sunose (KAS), were applied to thermogravimetric (TGA) data to calculate the effective activation energy Eα during a pyrolysis process. The results obtained by Kissinger’s method showed that the pyrolytic breakdown pathway of hemicellulose, cellulose, and lignin in a ligno-cellulosic biomass is independent of the heating rate and can be described through a simple first-order kinetic reaction (f(α) = 1 − α). The thermo-kinetic behavior obtained by isoconversional methods (Fr and KAS) of the hemicellulose degradation shows a progressive and monotonic increase in Eα with the conversion, between ~140 and ~195 kJ mol−1 with an average value of 172 kJ mol−1, which reveals the competitive character of the process (multi-step process). Conversely, in the cellulose degradation, the dependence o...

Pyrolytic degradation of peanut shell: Activation energy dependence on the conversion