Biodiesel Production from Tropical Almond (Terminalia Cattapa) Seed Oil Using a Bi-Functional Catalyst Derived from Almond Shell and Calcined Snail Shell

This study investigated the production of biodiesel from almond seed oil using bio-based heterogeneous catalyst developed from doped snail shell and almond shell. The Almond seed oil was characterized with low acid value of 0.28 mgKOH/g. The catalyst was characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Brunauer, Emmett and Teller (BET) analysis to assess its suitability. Biodiesel production was carried out via a single step transesterification process as planned utilizing the Box-Behnken Design (BBD). The process was modeled and optimized using the response surface methodology (RSM). The bi-functional catalyst had high surface area of 272.440 m2/g. An optimal yield of 98.80% was obtained with a methanol: oil ratio of 6, temperature of 60oC, catalyst loading of 1.50 wt%, and reaction time of 90 minutes. R2 value of 0.9840 was obtained, indication the adequacy of RSM in modeling biodiesel production. Biodiesel produced at the optimum conditions was within the specifications when compared with ASTM D6751 and EN 14214 standards.