Straight run gas oil as sulphur compound to preserve the sulphide state of the hydroprocessing catalyst of triglycerides

The hydrogenation of natural triglycerides to produce motor fuels has an increasing importance. Therefore increase the efficiency of the production is important. So a special case of hydrogenation of triglycerides was studied on a sulphided NiMo/Al2O3 catalyst at wide range of process parameters (Pressure = 40 and 80 bar, Temperature = 320-380 °C, Liquid Hourly Space Velocity = 0.75-2.0 h−1, H2/feed ratio = 600 m3/m3). The sulphur content of the feedstock was ensured with mixing a small amount (10%) of high sulphur containing (0.9%) gas oil into the sunflower oil to ensure the sulphided state of the catalyst. In comparison, the hydrogenation of a reference feedstock was examined which sulphur content was set to similar concentration (905 mg/kg) level by using an easily decomposable sulphur compound (dimethyl disulphide). By applying favourable process parameters (Temperature = 360-380 °C, Pressure = 80 bar, Liquid Hourly Space Velocity = 0.75 to 1.0 h−1, H2/feed ratio = 600 m3/m3) the properties of the products being obtained in high yield satisfied the requirements of the EN 590:2013 standard, except Cold Filter Plugging Point and density values for both feedstocks. In case of the catalytic hydrogenation of triglycerides it was concluded to cover the sulphur content of the feedstock with straight run (high sulphur containing) gas oil is a suitable and cost-effective solution to preserve the sulphide state of the catalyst. Diesel fuel can be produced with blending of products of high cetane and low density into other gas oil streams. The hydrogenated vegetable oil products can improve the quality of low-quality gas oil streams to produce better quality diesel fuel with bio-component content.