PILOT SCALE BIOCHAR PRODUCTION FROM PALM KERNEL SHELL (PKS) IN A FIXED BED ALLOTHERMAL REACTOR

Abstract

Oil palm biomass wastes such as oil palm fronds (OPF), empty fruit bunches (EFB) and palm kernel shells (PKS) are amongst the most abundantly available agricultural residues in Malaysia. Of these, an average 0.16 t PKS per tonne crude palm oil (CPO) is commonly used in palm oil mills as boiler fuel to generate steam and electricity, while the remaining unused 0.20 t PKS per tonne CPO are often sold as fuel. In order to diversify and add value to the remaining PKS, it is proposed to convert it into biochar to sequester CO 2 and improve the productivity of low-fertility soil. In this study, PKS was carbonised under allothermal conditions at various temperatures (400C to 600C) and residence times (30 and 60 min) using the biochar experimenters kit (BEK). Biochar yield decreased from 52.1 15.5 wt% at 400C (30 min) to 33.4 1.4 wt% at 600C (60 min), while pH, elemental and fixed carbon content increased with temperature and residence time. The VM/FC (0.25 to 0.60) and O/C (0.12 -0.23) ratios suggest that PKS biochar is an effective carbon sink with a half-life in soil > 100 years.