Pyrolysis investigation of food wastes by TG-MS-DSC technique

The slow pyrolysis characteristics of four food wastes, namely acorn cups (AC), acorn pericarp (AP), almond shells (AS), and nut shells (NS) were investigated by thermogravimetric (TG) analysis coupled with mass spectrometry (MS) and differential scanning calorimetry (DSC). Thermal degradation of these samples was divided into three stages corresponding to the removal of water, the devolatilization, and the formation of char; the differences in the thermal behavior of the samples are due to the differences in composition. The kinetic parameters of the process were calculated using the method of Coats-Redfern and by applying diffusion and chemical reaction kinetic models. The thermodynamic parameters were calculated for the formation of the active complex of the reagent. The main gaseous products formed during the pyrolysis were CO, CO2, H2O, CH4, and C2H4. The comparison of the pyrolysis characteristics shows that AS was more reactive and that AC require less energy to be converted. The current investigation suggested that within the realm of existing biomass conversion technologies, AC, AS, NS, and AP can be used as feedstock for energy recovery.