Temperature effect on co-hydroprocessing of heavy gas oil–waste cooking oil mixtures for hybrid diesel production

The effect of temperature on hydrotreating of heavy gas oil (HGO)–waste cooking oil (WCO) mixtures was studied. Three different types of feedstock were studied, 100% HGO, 90/10 HGO/WCO and 70/30 HGO/WCO. Temperature is the most dominant operating parameter which defines catalyst performance as well as catalyst life. In this analysis, a hydrotreating temperature range of 310–350 °C was explored via a series of three experiments (310 °C, 330 °C and 350 °C). Several parameters were considered for evaluating the effect of temperature including heteroatom removal, conversion, pour point, hydrogen consumption and saturation of double bonds. For all experiments the same commercial hydrotreating catalyst was utilized (NiMo/Al2O3), while the remaining operating parameters were kept constant (pressure = 1200 psig, LHSV = 1.0 h−1, H2/Oil ratio = 505.9 nl/l, liquid feed = 40 ml/h, and gas feed = 21804 ml/h).