The potential of silver nanoparticles as heterogeneous catalysts for generation of biodiesel from vegetable oils

Conventionally, biodiesel is synthesized from vegetable oils or waste cooking oils through extraction of oils from vegetables by extrusion/solvent extraction, degumming, and refining of oil followed by transesterification. This results into a significant increase in the cost of final product which in turn limits its chances of competing with petroleum diesel. It is reported herein, the use of silver nanoparticles supported alumina as heterogeneous catalysis for in situ generation of biodiesel from castor seeds powder. Prequel to biodiesel production, oil from the seeds of castor was extracted via soxhlet extraction method and analyzed for their physicochemical properties where 65% oil yield was obtained. The obtained silver nano catalyst was prepared by chemical reduction and was supported by loading same on Alumina. The catalyst was characterized by means of X-ray diffraction and X-ray Fluorescence. Result obtained from XRD analysis revealed absorption at 2θ=45 nm whereas XRF analysis revealed the presence of Ag and Al2O3 suggesting successful incorporation AgNPs onto Alumina. Optimization of various parameters affecting the transesterification process revealed thus; temperature equaling 60 °C, methanol to oil ratio of 6 and reaction time of 45 min. the biodiesel produced was further characterized for its fatty acid methyl ester profile using gas chromatograph coupled with mass spectrophotometer (GC-MS). The results indicated that the presence of methyl octadecanoate, methyl hexadecanoate and linoleic acid methyl ester.