Physicochemical properties evolution of chars from palm kernel shell pyrolysis

To clarify the effect of the pyrolysis operating conditions of the biomass on the physicochemical properties of the char and its combustion reactivity, palm kernel shell was pyrolyzed at different temperatures (400–700 °C). Analyses such as proximate and ultimate analysis, XRD, FTIR, N₂ adsorption, and SEM were used to investigate the physicochemical properties of biochar samples. The results show that an increase in pyrolysis temperature led to a development of pore structure and specific surface area of the produced biochar, which was beneficial for improving the biochar combustion reactivity. Besides, with increase in pyrolysis temperature, the carbon content exhibits a raise trend, but the oxygen and hydrogen contents exhibit the opposite behavior, and the aromaticity and graphitization degree of biochar produced at high temperature also increase. The combustion reactivity of biochar was found to be highly dependent on the pyrolysis temperature, and the aromatic structure and graphitization degree have greater effects on biochar combustion reactivity than those of the specific surface area and pore structure.