From organic waste to renewable energy: response surface methodology approach for optimized biodiesel production from palm weevil larvae (Rhynchophorus ferrugineus)

This study aimed to improve the production of biodiesel from white palm larvae (WPL) and to evaluate its potential as a feedstock. The larvae were grown using kitchen and palm waste for 21 days, and the crude oil was then extracted. The extracted oil was analyzed for its physicochemical properties and fatty acid composition. The analysis found that the feedstock oil contained a high quantity of monounsaturated fatty acids, indicating its suitability for biodiesel production. To optimize the production process, response surface methodology (RSM) was employed. A central composite design was used to study four operating conditions: temperature, methanol-to-oil mole ratio, esterification time, and catalyst loading for esterification, as well as transesterification time and catalyst concentration. The best conditions for esterification were a methanol-to-oil ratio of 18:1, a temperature of 70 °C, 120 min of reaction time, and a 4% H₂SO₄ catalyst. For transesterification, the optimal conditions were a methanol-to-oil ratio of 10:1, a temperature of 65 °C, 90 min of reaction time, and a 2% KOH catalyst concentration. The experimental data fit well with models, with significant P-values and high R² values. The biodiesel produced under the optimized conditions met the fuel quality standards set by Brazilian, European, and American standards. In conclusion, this study successfully optimized the biodiesel production process from white palm larvae and confirmed its suitability as a feedstock. The feedstock oil had properties that were suitable for biodiesel production, and the optimized conditions resulted in biodiesel that met fuel-quality standards.