This study describes the effect on properties of palm kernel shell (PKS) and Mukah Balingian (MB) coal by thermal pretreatment. The PKS and MB coal were torrefied and preheated, respectively in a fixed-bed reactor at different temperatures. The pretreated samples were analysed for mass and energy yield, proximate, ultimate and functional group analysis. The thermal and kinetic studies of the upgraded materials were conducted using thermogravimetric analyser (TGA). The results showed that the properties of pretreated samples were improved with increasing heating temperature. The oxygen content and O/C ratio of upgraded samples were decreased by increasing the heating temperature. The reduction of oxygenated peak in the functional group analysis indicates that the thermal pretreatment has cleaved the oxygen and hydrogen bonding. The upgraded PKS at torrefaction temperature of 270 degrees C demonstrated that activation energy of 10034 kJ/mol with the highest mean reactivity of 0.86. MB coal at preheated temperature of 250 degrees C showed activation energy of 122.35 kJ/mol with the highest mean reactivity of 0.063. Thus, from the analysis of upgraded samples, the torrefied PM at 270 degrees C and preheated MB coal at 250 degrees C demonstrated a good quality feedstock to be used in thermal conversion such as in co-gasification. (C) 2018 Elsevier Ltd. All rights reserved.