Energy consumption is continuously growing world-wide. Due to tightening environmental regulations and to reduce dependency on fossil fuels the demand for alternative fuels is increasing in the EU. At the same time the use of first generation biofuels is limited because of their inappropriate properties and feedstocks. First generation biofuels are mainly produced from edible feedstocks. So this is important to investigate the utilisation of waste based sources and new methods to produce new, alternative fuel components with better properties. Waste fatty acids can be promising feedstocks for alternative fuel production, since hydrocarbons can be produced from them with oxygen removal reactions. There is little information about the hydrogenation of fatty acid mixtures in the literature; most of the studies are about the conversion of model compounds. Real waste fraction with high fatty acid content (> 90 %) has high oxygen and olefinic double bond content (> 78 %). These are heat and oxidation sensitive compounds. Hydrocarbon fraction with mainly normal-paraffins can be produced with the hydrogenation of these compounds. These paraffins are good blending components of engine fuels with favourable performance properties. The aim of our work was to study the production of high quality diesel fuels with alternative component content from the different mixtures of waste fatty acids and highsulphur, crude oil based light gas oil fractions. The quality improvement of mixtures of unrefined, winter grade gas oil fraction and fatty acids (10, 20 and 30 wt%) was carried out on a commercial, sulphided NiMo/Al2O3 catalyst. Our goal was to achieve the most complete hydrogenation of the unstable fatty acids (saturation and oxygen removal) and to practically remove the sulphur content of the gas oil fraction, furthermore, to saturate the aromatics (especially the polycyclic ones) as much as possible.
ASJC Scopus subject areas
- Chemical Engineering(all)