Pretreatment of palm kernel shell by torrefaction for co-gasification

This study describes the effect of pretreatment on palm kernel shell (PKS) by torrefaction for the possibility of co-gasification. PKS samples were torrefied at temperature of 210, 250 and 290°C for 60 min of holding time with nitrogen flow rate of 0.5 L/min and 1.0 L/min, respectively. The torrefied PKS were analysed for elemental composition, calorific value and chemical structure changes. The results showed that, carbon content of torrefied PKS samples were closed to that of coal properties with comparable calorific values were obtained. It was also found that the effect of nitrogen flow rate was insignificant on the conversion, mass and energy yield of torrefied PKS. Moreover, with the increase of torrefaction temperature, the oxygen content, O/C ratio and functional groups of oxygenated components of torrefied PKS were reduced. However, the conversion of raw biomass was found to increase with increasing torrefaction temperature. The torrefied PKS demonstrated a good quality feedstock at torrefaction temperature between 250°C to 300°C. Thus, it can be concluded that the change in physical and chemical properties of torrefied PKS revealed the potential of applying PKS and coal in co-gasification for high quality syngas production.