Abstract:
Biodiesel or fatty acid methyl ester (FAME) is considered one of the most promising alternative fuels. It has a higher cetane number than diesel; however, there are some problems related to oxidative stability and the cold flow properties. These properties depend on the degree of unsaturation in the FAME chains. Therefore, the quality of biodiesel can be improved by partial hydrogenation. The main objectives of this work were to study the effect of metal type; Pd, Pt, and Ni, and also study the effect of sulfur compound on different metal types in the partial hydrogenation of soybean oil based-biodiesel. The catalytic activity of all catalysts dropped after adding additional sulfur. The highest catalytic activity of hydrogenated biodiesel both before and after adding additional sulfur was represented by Pd/SiO₂. However, the highest sulfur tolerance was exhibited by Pt/SiO₂ (37.05 % loss activity). The results indicated that partial hydrogenation reaction was the efficient method to improve the biodiesel properties by increasing the oxidative stability.
