Pyrolysis and gasification kinetic behavior of mango seed shells using TG-FTIR-GC–MS system under N 2 and CO 2 atmospheres

Mango waste is one of the most promising sources of renewable energy, especially as this waste represents 40% of the weight of mango fruit and contains a large amount of fat and cellulose that can contribute to converting it into energy products using pyrolysis and gasification process. Within this context, this research aims to investigate pyrolysis and gasification kinetic behavior of mango seed shells (MSS) using TG-FTIR-GC–MS system. The experiments were started by analyzing the composition of different types of Egyptian MSS, then their pyrolysis characteristics and chemical decomposition in N 2 and CO 2 atmospheres using TG-FTIR system upto 900 °C at heating rates in the range 5–30 °C/min were studied. The GC/MS system was employed to determine the formulated volatile products at the maximum decomposition temperatures (343–346 °C for N 2 and 334–340 °C for CO 2 ). Afterwards, the model-free/model-fitting methods, including Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, and Friedman, and Distributed Activation Energy Model (DAEM) were used to estimate the kinetic parameters of pyrolysis of MSS in both atmospheres. Finally, chars derived from pyrolysis were exposed to CO 2 gasification process, followed by studying of their kinetic behavior in the modified random pore model (MRPM). The results showed that the decomposed MSS were saturated with a huge amount of volatile products, particularly Carbon dioxide and Ethylene oxide (99.27% in CO 2 and 20.77% in N 2 ), while Acetic acid, Propanone, Hexasiloxane, Glycidol, Ethanedial, Ethylene oxide, Formic acid, etc. were the main compounds in case of N 2. Meanwhile, the studies of kinetics of pyrolysis showed that the average activation energies were estimated in the range of 231–262 kJ/mol (N 2 ) and 259–333 kJ/mol (CO 2 ). Based on that, pyrolysis and gasification can be adapted as promising technologies to valorize MSS and utilize them as a new sustainable source for renewable energy.