Activated Charcoal Modified with Chromium Oxide as Catalyst for Groundnut Oil Transesterification

Abstract

A gradual shift to biofuels development was considered advantageous in reducing the pollution and other challenges associated with fossil fuels. Specifically, biodiesel production is one of those options prioritized in the literature. Herein, we demonstrated how a modified activated charcoal sample and chromium oxide can catalyze the upgrading of groundnut oil into fuel-grade biodiesel at the laboratory scale via trans-esterification with methanol. The charcoal-based catalyst was characterized mainly at mole ratio: 3:1 (methanol: oil) reaction time of 1hr and reaction temperature at 60°C. The yield of biodiesel produced were found 71.50% for activated modified charcoal, 59.30% for chromium oxide and 49.45% for charcoal only, which is a little lower than that obtained by some researchers, and the density was found to be 0.56/cm³ for active modified charcoal, 0.43g/cm³ for chromium oxide and 0.33g/cm³ for charcoal only which is within the ASTM approved limits. The viscocity was found to be 3.39mm²/s, 2.52 mm²/s and 1.85 mm²/s for modified activated charcoal chromium oxide and charcoal respectively at 40°C. The free fatty acid was found to be 0.01%, 0.04% and 0.02% for modified activated charcoal, chromium oxide and charcoal respectively and the values are within the range approved by ASTM. The saponification values obtained were 0.56mgKOH/g, 0.84mgKOH/g and 1.12mgKOH/g for modified activated charcoal, chromium oxide and charcoal respectively. Trans-esterification method is found to be good in producing by biodiesel from groundnut oil as corroborated by several investigations.