Pyrolysis of torrefied oil palm wastes for better biochar

Abstract

The objective of this research work is to investigate the effect of torrefaction on the pyrolysis product. Biomass materials such as empty fruit bunch (EFB), mesocarp fibre (MF) and palm shell (PKS) were torrefied and pyrolyzed. The experiment conditions were set to be respectively at 220 o C of temperature, 10 o C/min of heating rate and 30 minutes holding time for torrefaction and at 650 oC of temperature, 20 o C/min heating rate and  2 hours holding time for pyrolysis. Nitrogen flow rate of 2L/min was maintained for both experiments. The torrefied biomass contains high carbon content and low oxygen content than the raw biomass. Also, the biochar derived from torrefied biomass have high fixed carbon content than the biochar derived from untorrefied biomass. The maximum higher heating value (HHV) of about 31.2 MJkg-1 is obtained in the biochar derived from the torrefied shell. Though, all the biomass materials used in this research have exhibited a positive outcome after being torrefied and pyrolyzed. It is clear from scanning electron microscopy (SEM) images that the biochar (b) and (d) derived from torrefied biomass could be better in the application of soil amendment and water retention due to a large number of uniform holes. Therefore, it can be concluded that pyrolysis of torrefied biomass improved the quality of biochar than the biochar obtained from untorrefied biomass.