The Effect of the Reaction Conditions on the Properties of Products from Co-Hydrotreating of Rapeseed Oil and Petroleum Middle Distillates

Abstract

This study compares the hydrotreating of the mixture of petroleum middle distillates and the same mixture containing 20 wt % of rapeseed oil. We also study the effect of the temperature and the weight hourly space velocity (WHSV) on the co-hydrotreating of gas oil and rapeseed oil mixture. The hydrotreating is performed over a commercial hydrotreating Ni-Mo/Al2O3 catalyst at temperatures of ca. 320, 330, 340, and 350 °C with a WHSV of 0.5, 1.0, 1.5, and 2.0 h−1 under a pressure of 4 MPa and at a constant hydrogen flow of 28 dm3·h−1. The total conversion of the rapeseed oil is achieved under all the tested reaction conditions. The content of the aromatic hydrocarbons in the products reached a minimum at the lowest reaction temperature and WHSV. The content of sulphur in the products did not exceed 10 mg∙kg−1 at the reaction temperature of 350 °C and a WHSV of 1.0 h−1 and WHSV of 0.5 h−1 regardless of the reaction temperature. Our results show that in the hydrotreating of the feedstock containing rapeseed oil, a large amount of hydrogen is consumed for the dearomatisation of the fossil part and the saturation of the double bonds in the rapeseed oil and its hydrodeoxygenation.