Determination of oxidation characteristics and decomposition kinetics of some Nigerian biomass

The oxidation characteristics and devolatilisation kinetics studies of palm kernel shell (Elaeis guineensis), African bush mango wood and shell (Irvingia wombolu), and African border tree wood (Newbouldia laevis), were carried out by the thermogravimetric method. A thermogravimetric analyser TA Q500 instrument was used at a heating rate of 30 °C.min-1 under oxidative conditions. It was observed that all the samples followed a two-stage structural decomposition between 200 °C and500 °C. The greatest mass loss rate occurred within the oxidation stage (200–375 °C) in all the samples. The ignition temperature of the samples ranged from 275–293 °C while their burnout temperatures ranged from 475–500 °C. During the oxidationstage, African bush mango shell was the most reactive sample, while palm kernel shell was the least. During the char combustion stage (375–500 °C), the reactivity of palm kernel shell was the highest. The average activation energy of the samples for the entire decomposition period are 140, 270, 131 and 231 kJ.mol-1 respectively. The biomass samples considered are thus suitable for combustion purposes for bioenergy production with minimal external energy input.