Synthesis and characterisation of a novel silica—CaO/TPA catalyst for biodiesel production

The current study describes the synthesis of a novel bifunctional heterogeneous catalyst that demonstrates exceptional performance and sustainability for the valorization of waste cooking oil into biofuel. The acid-base catalyst was described by using different analytical techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Brunauer-Emmet-Teller Analysis (BET), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-Ray Spectroscopy (EDX). The composition of biofuel was determined by using Gas Chromatography- Mass Spectrometry (GC-MS) and FTIR. The novel catalyst comprised a synergistic combination of silicon dioxide, calcium oxide, and tungstophosphoric acid, exhibiting a remarkably high surface area of 155.89 m²/g due to its meticulously engineered porous structure. SEM micrographs unveiled a porous network structure composed of spherical particles, further substantiating the catalyst’s potential for efficient biodiesel synthesis. Under optimal conditions, the catalyst demonstrated a 93.6% conversion of waste cooking oil to a diverse biodiesel product rich in saturated, monounsaturated, and polyunsaturated fatty acid methyl esters, which was validated by rigorous characterization. Notably, this catalytic approach not only enhances a waste feedstock but also employs a reusable, cost-effective catalyst, rendering it an environmentally benign and economically viable process.