Renewable diesel synthesis from sesame indicum (bene) seed oil using novel heterogeneous biocatalyst derived from the Chrysophyllum albidium seed coat

Abstract

The synthesis, characterization, optimization and oxidation stability improvement of biodiesel from the seed oil of sesame indicum using a novel nano-heterogeneous bio-catalyst derived from the Chrysophyllum albidium seed coat (CASC) is reported. The heterogeneous catalyst was produced by calcination and activation at 400 °C, 600 °C and 800 °C using acetic acid. The catalyst was characterized using scanning electron monograph (SEM), Fourier transform infrared (FTIR), and x-ray diffraction (XRD). The seed oil was extracted using mechanical press milling and the biodiesel produced were characterized using AOAC 2019 edition and ASTM D-6151, Fourier transform infrared (FTIR) and gas chromatography (GC) methods. The results indicated that calcined Chrysophyllum albidum seed coat contains nano-particles and alkaline elements (75 % graphite). The calcination process improved the size reduction and structural arrangement of the particles. The 600 °C calcination temperature had the highest biodiesel yield of 88 % at 3.0 wt % catalyst concentration, 12:1 M ratio of alcohol to oil and 500 rpm. The reusability of catalyst indicated 71.50 % after fifth (5th) cycle. After 28 days storage duration in the presence of the natural, renewable and eco-friendly antioxidant (1 % turmeric), the oxidation instability of the produced biodiesel was reduced by 50 %. The quality of the biodiesel indicates agreement with standards and literature as well as high potential for effective application in diesel engine.

Keywords

• Heterogeneous catalyst
• Sesame indicum
• Characterization
• Biodiesel
• Reusability
• Oxidation stability