The prospect of silver (Ag) nanoparticles as mixed nano catalyst

Abstract

Conventional method for the synthesis of biodiesel from vegetable oils entails isolation of oils by extrusion or solvent extraction, degumming, and refining of oil followed by transesterification. This significantly adds to the high cost of biodiesel production from vegetable oils. Herein, we report for the first time, the development of alumina supported silver nano particles as heterogeneous catalysts 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 =45nm 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^o 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 indicate the presence of methyl octadecanoate, methyl hexadecanoate and linoleic acid methyl ester. Biodiesel's fuel properties analysis indicates 5 cSt, 90oC, 0.97, 7.3/100g, 0.012?% and 1.9mgKOH/g for kinematic viscosity, flash point, specific gravity, iodine value, sulphur content and acid value respectively.