Research Article
Sustainable Biodiesel Synthesis from Waste Cooking Oil Using Eggshell and Coffee Husk Catalyst
@INPROCEEDINGS{10.4108/eai.6-11-2025.2364458, author={Vebria Ardina and Vany Mei Lia and Rahmi Rahmi and Lenny Marlinda}, title={Sustainable Biodiesel Synthesis from Waste Cooking Oil Using Eggshell and Coffee Husk Catalyst}, proceedings={Proceedings of the 4th Sriwijaya International Conference on Basic and Applied Sciences, SICBAS 2025, 6 November 2025, Palembang, Indonesia}, publisher={EAI}, proceedings_a={SICBAS}, year={2026}, month={8}, keywords={Biodiesel waste cooking oil CaO--K₂O catalyst eggshell coffee husk}, doi={10.4108/eai.6-11-2025.2364458} }- Vebria Ardina
Vany Mei Lia
Rahmi Rahmi
Lenny Marlinda
Year: 2026
Sustainable Biodiesel Synthesis from Waste Cooking Oil Using Eggshell and Coffee Husk Catalyst
SICBAS
EAI
DOI: 10.4108/eai.6-11-2025.2364458
Abstract
The production of biodiesel from renewable waste materials offers a sustainable alternative to fossil fuels. This study utilized waste cooking oil (WCO) as a feedstock and developed a heterogeneous CaO–K₂O composite catalyst derived from eggshells and coffee husks. The catalyst was synthesized through calcination at 900 °C for 3 hours and characterized using X-ray Diffraction (XRD). Transesterification was conducted at 65 °C with a methanol-to-oil molar ratio of 9:1, a 60 minute reaction time and catalyst loadings ranging from 0.5–3 wt%. XRD analysis confirmed the successful formation of active CaO phases and the in-corporation of potassium species. The highest FAME yield of 71.7% was obtained at 0.5% catalyst loading. The produced biodiesel exhibited a density of 0.91-0.92 g/mL and a heat-ing value of 5.016 kcal/kg. These results indicate that eggshell and coffee husk composites are potential low-cost catalysts for biodiesel production.
