Heavy Metal Analysis in Biocoke Fuel Derived from Empty Fruit Bunch (EFB) Waste

Abstract

This study aims to analyze the effect of carbonization temperature on the concentration of heavy metals in biocoke produced from oil palm empty fruit bunches (EFB). EFB samples were carbonized at three different temperatures, namely 300°C, 400°C, and 500°C, to evaluate the effectiveness of the process in reducing the content of heavy metals such as Pb, Cd, Zn, Cr, Cu, Ni, and Hg. The results showed that increasing the carbonization temperature significantly reduced the concentration of heavy metals in biocoke products. The concentration of Pb decreased by 44% from 2.15 mg/kg at 300°C to 1.20 mg/kg at 500°C. Similarly, Cd decreased by 47% from 0.85 mg/kg to 0.45 mg/kg, while Zn decreased by 37% from 15.20 mg/kg to 9.60 mg/kg. ANOVA statistical analysis strengthens this finding by showing significant F-values ​​for Pb (12.35 with p=0.001), Cd (15.20 with p=0.000), and Zn (10.50 with p=0.003). Based on these findings, applying high carbonization temperature, especially 500°C, is recommended to minimize the content of heavy metals, thus producing a more environmentally friendly biocoke that is safe to use as an alternative fuel. This study provides important insights for developing renewable energy from biomass in Indonesia.