Co-hydroprocessing gas-oil with residual lipids: effect of residence time and H2/Oil ratio

Co-hydroprocessing of petroleum fractions with residual lipids is a promising technology for hybrid fuels production. The aim of this study is the identification of an effective operating window for co-hydroprocessing of Heavy Atmospheric Gas Oil (HAGO) with Waste Cooking Oil (WCO) within the nominal operating limits of a refinery. In particular, two Liquid Hourly Space Velocities or LHSVs (0.66 and 1 h(-1)) and three hydrogen-to-oil or H-2/Oil ratios (300, 400 and 500 L H-2/L feed) were studied for a HAGO/WCO 90/10 V/V blended feedstock over a commercial hydrotreating NiMo/Al2O3 catalyst. The two parameters were evaluated with respect to the attained diesel content and quality of the produced hybrid fuels. All experiments were performed at a constant pressure of 5.6 MPa and temperature of 350 degrees C. The results have shown that higher LHSV is preferable in terms of the hydrogen consumption affecting the conversion cost. As far as H-2/Oil is concerned, high H-2/Oil ratios are more effective, rendering higher conversion, diesel content and heteroatom removal. (C) 2016 Elsevier Ltd. All rights reserved.