Production and Characterization of Low-ash Empty Fruit Bunches (EFB) Pellets as a Solid Biofuel

Abstract

Fuel quality is among the major issues encountered for commercial production and utilisation of oil palm-based biomass pellets from empty fruit bunches (EFB). In this study, a physical treatment, namely sieving and water washing, was applied to EFB prior to densification using an industrial-scale plant. The physiochemical properties of the produced EFB pellets were compared with those without physical treatment as the control. The results showed that the physical treatment process had significantly enhanced the fuel properties of EFB pellets, particularly in reducing ash content. Both the treatments; sieving alone and a combined sieving and water washing of the feedstock managed to reduce the ash content of EFB pellets to < 4 wt.% and < 2 wt.%, respectively compared to > 5 wt.% of typical commercial EFB pellets. The reduction in ash content improved the calorific value of pellets to > 17.5 MJ kg-1 which signified achieving a milestone for oil palm biomass-based heat and power generation from technical, operational, economic and environmental points of view. The findings also indicated that the combined sieving and water washing treatment method could potentially reduce further the unwanted ash-inducing elementals in EFB pellets, in particular chlorine and potassium. This study demonstrated that the employed physical treatment is an immediate and cost-effective practical commercial approach to improve the fuel properties of EFB pellets.