Catalytic Synthesis of Biodiesel from <em>Milletia pinnata</em> over Modified forms of Zirconia coated on Honeycomb Monoliths

Abstract

In this article an economical, efficient and eco-friendly method developed for the catalytic synthesis of biodiesel is presented. Honeycomb monoliths were coated with zirconia (ZrO₂) and its modified forms such as Mo (VI)/ZrO₂, Cr (VI)/ZrO₂, Ca (II)/ZrO₂ and Ba (II)/ZrO₂ by using dip and dry method. These catalytic materials were characterized for their physico-chemical properties such as surface acidity, surface basicity, crystalinity, functionality, morphology and elemental analysis. ZrO₂, Mo (VI)/ZrO₂ and Cr (VI)/ZrO₂ coated on honeycombs were used as solid acid catalysts for the esterification of <em>Milletiapinnata</em> oil with methanol to reduce the percentage of free fatty acids. ZrO₂, Ca (II)/ZrO₂ and Ba (II)/ZrO₂ were used as solid base catalysts for the transesterification of esterified <em>Milletiapinnata</em> oil with methanol to synthesize biodiesel. The catalysts were also prepared in their powder forms and their catalytic activities were compared with that of their honeycomb coated forms. The effect of reactivation and reusability of catalytic materials on their catalytic activity is also discussed. It was observed that a two-fold increase in the catalytic activity of honeycomb coated forms was obtained when compared to the powder form of the catalysts.