Integrating Waste Valorization and Green Energy: Biodiesel Production Using Microwave-Derived Chitosan Catalyst from Raw Tilapia ( Oreochromis Niloticus ) Scales

This study presents an integrated approach to biodiesel production using waste vegetable oil (WVO) and chitosan derived from raw tilapia (Oreochromis niloticus) scales, synthesized via microwave-assisted methods. The chitosan acted as a heterogeneous catalyst during the transesterification of pre-treated WVO. Key process parameters included esterification and transesterification stages, with acid value and volume changes monitored throughout. Characterization of the resulting biodiesel was conducted in accordance with the Philippine National Standard PNS/DOE QS 002:2015, focusing on total sulfur content, water and sediments, and Fatty Acid Methyl Ester (FAME) content. The final product exhibited compliant sulfur and water levels, though the FAME content remained below specification, attributed to limited glycerol separation time. Despite this, the process achieved a 64% conversion and reduced the acid value from 2.11 to 0.262 mg KOH/g, indicating high potential for further optimization. This research supports sustainable fuel development while promoting circular utilization of agrowaste in developing economies.