Converting waste cooking oil into biodiesel using phosphomolybdic acid/clinoptilolite as an innovative green catalyst via electrolysis procedure; optimization by response surface methodology (RSM)

The present study aims to convert waste cooking oil (WCO) into biodiesel via phosphomolybdic acid (H3PMo12O40, PMA) supported on Clinoptilolite as a novel green acid catalyst through an electrolysis procedure. The prepared catalysts were characterized by XRD, FTIR, FESEM, EDS, Elemental map, and TEM analyses. The effect of four independent variables on biodiesel yield including methanol to oil molar ratio (6:1-14:1), catalyst weight (2-5 wt%), time (3-5 h), and voltage (15-35 V) was optimized and evaluated by the response surface methodology (RSM) employing central composite design (CCD). The maximum value of biodiesel yield was 96% under the optimal conditions, including the methanol to oil molar ratio of 9:1, catalyst weight of 3 wt%, time of 4 h, and voltage of 21 V at room temperature. The catalyst was reused five times with an average yield of similar to 83.4%. The biodiesel production was confirmed by FTIR and H-NMR analyses, with its chemical and physical characterizations being in agreement with the ASTM standard. In conclusion, the fabricated biodiesel from WCO is an economical and environmentally friendly procedure thanks to cheap primary feedstock and catalyst.

Automated summary

This study successfully utilized phosphomolybdic acid supported on Clinoptilolite as a green acid catalyst for converting waste cooking oil into biodiesel. Optimization using response surface methodology led to a maximum yield of 96%, and the biodiesel production was confirmed to meet ASTM standards through FTIR and H-NMR analyses. The reuse of the catalyst for multiple cycles further demonstrated the feasibility and efficiency of the biodiesel production process.