Thermal pyrolysis and kinetic parameter determination of mango leaves using common and new proposed parallel kinetic models

Abstract

TG/DTG thermal pyrolysis analysis is performed under nitrogen from 100 to 1000 °C at three different heating rates for three types of most famous Egyptian mango leaves to be used as a biomass fuel. Proximate and ultimate analysis, organic composition, metallic components as well as thermal degradation and their characteristic properties are determined and deeply investigated to recognize the possibility to use them as a source of renewable energy. A maximum volatile released method and three isoconversional kinetic models were used to analyze the dependence of the activation energy (E_α) on the degree of conversion. A double parallel random pore model (DRPM), mixed volumetric random pore model (MVRPM) and a new proposed double parallel volumetric model (DVM) were used to investigate the kinetic parameters of the produced volatile and char. Three zones were chosen based on the organic composition and the temperature range of each mango leaf type. The maximum rate loss and second derivative of conversion of volatile matter (α) with temperature are used in the maximum volatile method at peak temperature for determining the kinetic parameters. The three isoconversional kinetic methods give almost closest values of E_av for all sub-zones and especially for a whole volatile zone of Sukari momtaz. The estimated E_av from the isoconversional methods are more dependable than the maximum volatile release method. Compared with previous multireaction models, the new proposed double parallel model can effectively investigate the pyrolysis kinetics of biomass materials.