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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.

Two-phase flow is widely encountered in several engineering and industrial facilities. The purpose of this study is to investigate the characteristic of slug countercurrent flow pattern in a vertical small diameter pipe. An experimental investigation in this study has been performed toward a transparent tube of 19 mm diameter (outside diameter 22 mm, length 200 mm), water and air as the liquid and gas fluid in the vertical pipe followed by taking a picture of flow pattern in the transparent pipe using the high-speed camera. Two differential pressure sensors were set in transparent tube in order to receive slug countercurrent flow rate associated with the acquisition data as media to record data and then displayed on the screen. The two-phase flow was always preceded by the instability of flow rate and bubbles appearance. It occurred after the steady flow data acquisition rate was turned on for recording the differential pressure. The result showed that the flow pattern characteristic of two-phase flow (air-water) in the vertical pipe caused by the superficial velocity of air.