Garção, Maria Isabella LimaMilani, Eduardo CandidoCamilo, Gabriel LaminoDiaz De Tuesta, Jose L.Gomes, Maria Carolina SérgiRibeiro, António E.Queiroz, AnaBrito, Paulo2025-11-212025-11-212025Garção, Maria Isabella Lima; Milani, Eduardo Candido; Camilo, Gabriel Lamino; Diaz De Tuesta, Jose L.; Gomes, Maria Carolina Sérgi; Ribeiro, António E.; Queiroz, Ana; Brito, Paulo (2025) Cork waste-based adsorbents for glycerol removal from biodiesel: a sustainable alternative to wet washing. ISSN 1759-7269. p. 1-171759-72691759-7277http://hdl.handle.net/10198/35128This work aims to use activated carbon from industrial cork waste as a novel method for glycerol removal from crude biodiesel produced using waste cooking oil, combining two residues to obtain both high-quality biodiesel and highly adsorbent activated carbon. The study first optimizes the biodiesel production conditions, achieving the highest ester yield at 30 degrees C, with a 1:9 oil-to-ethanol molar ratio, 1 wt.% NaOH catalyst, and a reaction time of 1 h. Additionally, activated carbons were prepared and characterized from cork waste, showing significantly higher BET surface areas than the raw material. The most promising cork-based materials were then applied to optimize glycerol removal from crude biodiesel through adsorption. A preliminary study identified milled raw cork and its KOH-activated carbon (SBET = 2057 m2/g) as the most effective. Kinetic and equilibrium studies demonstrated that optimal glycerol removal was achieved after 6 h at 25 degrees C using 2 wt.% of KOH-activated cork-based adsorbent, resulting in 88% glycerol removal and a final glycerol content of 0.017 wt.%. These findings demonstrate that cork waste-derived activated carbon is highly effective for biodiesel purification, successfully meeting the quality specifications required by European Standard EN 14214:2012+A2:2019 and offering an innovative solution for waste valorization and sustainable fuel production.engBiodiesel purificationGlycerol removalAdsorption equilibriumAdsorption kineticsActivated carbonjournal article10.1080/17597269.2025.2517453