Waste-to-Energy Conversion: Integrated Approach for Biodiesel Production From Used Cooking Oil by Citrus Waste Peel-Based Biocatalysts in Support of SDG 3 and 12.

The increasing multiple usage of waste cooking oil and citrus waste residues has created significant major health and environmental concerns. This research drives an approach towards sustainable resource recovery over a renewable feedstock. The orange and lemon peel waste performers catalytically were evaluated after the trans-esterification of used cooking vegetable oil (UCO/UVO). This process is optimized by parameters, like 10% catalyst, 12:1 methanol-to-oil ratio, Reaction temperature 80 °C, and reaction time 24 hours, to achieve maximum biodiesel yield up to 14% increment in the taken reactants. The process used two types of oils palm and soyabean, mostly used by hawkers to cook food and synthesized two types with four varied biodiesels. These were characterized using a standard 3/27 physicochemical analyses to determine biodiesels as a fuel quality. The findings indicate to an extent a promising, low-cost, zero-emission and environmentally friendly alternative (citrus peel-derived bio-based) for biodiesel production from UCO/UVO. This integrated multistep green synthesis bioprocess achieves Sustainable Development Goal 3 and 12 of health well-being along with responsible production. This study represents an integrated waste valorization approach towards circular economy, reducing dependence on conventional catalysts and even fossil fuels, and minimizes environmental pollution.