Numerical Studies on Fast Pyrolysis of Palm Kernel Shell in a Fluidized Bed Reactor

Numerical studies using Computational Fluid Dynamics (CFD) of thermal decomposition of Palm Kernel Shell (PKS) have been conducted in a fluidized bed reactor under atmospheric pressure of nitrogen as fluidization gas. To investigate the effect of temperature, the fast pyrolysis temperature was varied in a range from 400 °C to 650 °C. Furthermore, the effect of PKS feeding rate was also studied in a range from 300 g/h to 1500 g/h combined with variations of nitrogen superficial velocities. It was found that the increase of temperature results in the greatening of conversion efficiency and non-condensable gas product yield. The maximum 60.5 % liquid/tar product yield was obtained in 500 °C. The increase of PKS feeding rate led to the reduction of conversion efficiency due to the thermal energy shortage for the decomposition process. However, the increase of PKS feeding rate could reduce the non-condensable gas product with the insignificant change in liquid product yield. The rising superficial velocity of nitrogen favoured the shorter residence time resulting in the increasing tar product yield.