Thermogravimetric pyrolysis investigation of pistachio shell for its potential of thermal properties, kinetics and thermodynamics

Abstract In order to design and optimize thermochemical systems for the production of bioenergy understanding the energy capacity of the pistachio shell and its kinetics of degradation is crucial. The Thermogravimetric analysis at different heating rates of biomass was studied along with thermodynamic study, primary characterizations like the composition of biomass, heating value and a reaction mechanism-assisted kinetic model. Nitrogen gas flow rate is used for thermogravimetric analysis (TGA), which is performed at 10, 15, 20 and 30 ℃/min different heating rates from room temperature to 900 ℃. The output also shows that maximal degradation took place between 180 and 430 °C. The various iso-conversional models, such as Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink and Friedman, are used to calculate kinetic and thermodynamic parameters, which give the average value of activation energy as 172.29, 170.47, 169.79, and 193.25 kJ/mol. The average values of Gibbs free energy for the FWO, KAS, Starink and Friedman techniques were found to be 176.49, 1176.54, 176.29, and 175.78 kJ/mol, respectively. Graphical Abstract