Upgrading Oil Palm Empty Fruit Bunch Bio Oil via Catalytic Hydrodeoxygenation Using Nickel Impregnated Activated Carbon and Natural Zeolite Catalysts

Abstract

Biomass is a promising alternative energy feedstock because of its cellulose, hemicellulose, and lignin content and its availability as an agricultural and plantation residue. Pyrolysis can convert biomass into bio-oil, a complex liquid containing oxygenated compounds such as ketones, acids, phenols, alcohols, aldehydes, and hydrocarbons. This study evaluates the upgrading of crude bio oil (CBO) derived from oil palm empty fruit bunches (EFB) using nickel impregnated activated natural zeolite (ZAA/Ni) and nickel-impregnated activated carbon (AA/Ni) catalysts under hydrodeoxygenation (HDO) conditions. The physicochemical properties and available GCMS results were compared descriptively before and after upgrading. After correction of the compound classifications and recalculation from the listed GCMS peaks, the hydrocarbon peak-area totals were 20.59% for CBO, 20.36% for ZAA/Ni, and 26.66% for AA/Ni. The AA/Ni-treated bio oilshowed an increase in higher heating value (HHV) from 39.13 to 40.27 MJ/kg. Because the original chromatograms and independent replicate measurements were unavailable for this revision, the GCMS results are interpreted as semi quantitative, and the numerical differences are not presented as statistically significant. Overall, AA/Ni showed the more favorable combination of oxygen removal and HHV improvement under the tested conditions, although the increased viscosity indicates that further stabilization or fractionation would be required before considering diesel-equivalent applications.