Yanti, R.N. , Joni, R. and Yelmiza 2026. Upgrading Oil Palm Empty Fruit Bunch Bio Oil via Catalytic Hydrodeoxygenation Using Nickel Impregnated Activated Carbon and Natural Zeolite Catalysts. Indonesian Journal of Environmental Management and Sustainability. 10, 4 (Oct. 2026), 380-389. DOI:https://doi.org/10.26554/ijems.2026.10.4.380-389.