thermal stability and thermal decomposition kinetics of ginkgo biloba leaves waste residue

Abstract

Non-isothermal thermogravimetric (TG) analysis was used to investigate the thermal stability and kinetics of three types of Ginkgo biloba leaves. These three types of Ginkgo biloba leaves included: Ginkgo biloba leaves before enzymolysis and ultrasound extraction (G1), Ginkgo biloba leaves after enzymolysis and ultrasound extraction (G2), and Ginkgo biloba leaves after soxhlet extraction (G3). Thermogravimetric/dynamic thermogravimetric, (dynamic TG) experiments indicated that the thermal stability of G2 and G3 were weaker than G1. Kissinger, Flynn-Wall-Ozawa, Friedman, and Coats-Redfern methods were firstly utilized to calculate the kinetic parameters and predicted decomposition mechanism of G1, G2, and G3. The thermal decomposition of G1, G2, and G3 were all corresponded to random nucleation and growth, following the Avrami-Erofeev equation, and activation energy of which were 191.4, 149.9, and 201.6 kJ/moL, respectively. In addition, the thermal decomposition G1, G2, and G3 were endothermic, irreversible and non-spontaneous.