Partial hydrogenation of poly-unsaturated fatty acid methyl esters for biodiesel upgrading using Pd/activated carbon

Abstract

Biodiesel, which is defined as fatty acid methyl ester (FAME), is derived from renewable biological sources. The advantages of biodiesel over petroleum diesel are the improvement in lubricity, higher flash point, lower toxicity, lower emissions of SOX, CO, NOX, and biodegradability. However, the use of biodiesel is limited by some of its characteristics, which are oxidative stability and cold flow properties. Therefore, partial hydrogenation was used to upgrade the properties of biodiesel, especially the oxidative stability. Pd supported on various types of activated carbon catalysts were prepared by impregnation. The reaction was carried out at 120 ℃, 4 bar, 500 rpm stirring rate, and 1.5 wt.% of catalyst compared to starting oil. The results showed that the Pd/granule activated carbon exhibited higher activity in term of partial hydrogenation than Pd/activated carbon (850pm) and Pd/carbon aerogel, respectively.