Study Of Hydrotreating Catalyst And Technology For Mixture Of Gas Oil And Light Cycle Oil

The paper used carbon black as pore-expanding agent to prepare supports of gas oilhydrotreating catalyst and investigated the effects of the amount on the pore structure. Theresults showed that the support which was prepared by adding5wt%carbon black had largestspecific surface area, larger pore volume and highly centralized pore distributions,75%ofwhich are in the range of4nm to10nm. These properties meet the requirements for support ofFCC feed pretreating catalyst well.With NiMo as the active components, a series of NiMoP/Al2O3catalysts were preparedby incipient wetness impregnation method and the impacts of calcination temperature onproperties of the catalyst and activity of FCC feed pretreating were examined. With theraising of calcination temperature, the interaction between active component and supportstrengthened, the number of single MoS2slabs in sulfuretted active phase increased while thenumber of multiple MoS2slabs decreased, the length of the slabs got shorter and thedispersion of edge and corner Mo atoms rose. When the calcination temperature exceed350℃, the active components agglomerated and sintered partly as the further raising ofcalcination temperature. It indicates that catalyst calcinated at200℃had higher dispersion ofMo atoms, more available active sites and better HDS and HDN activity of FCC feedhydrotreating.A hydrorefining catalyst for light cycle oil(LCO) was graded with the hydrotreatingcatalyst for gas oil prepared previously and its activity was evaluated by using LCO and FCCfeedstock of Chinese Sinopec Qingdao Refinery as feed. The research results showed that thegrading catalyst had excellent HDN activity for LCO hydrorefining, and the HDS rate was90.6%and HDN rate reached96.7%under the condition of8.0MPa,370℃, LHSV1.5h-1,H2/Oil400:1. The grading catalyst also had good HDS and HDN activity for gas oil hydrotreating, and the HDS rate got to94.4%and HDN rate was up to88.2%under thecondition of10.0MPa,370℃, LHSV1.25h-1, H2/Oil700:1.Using mixture of LCO and FCC feedstock of Chinese Sinopec Qingdao Refinery as feed,the hydrorefining activity was tested. Under the condition of10.0MPa,370℃, LHSV1.25h-1,H2/oil700:1, the properties of hydrotreated LCO meet National Ⅲ Emission Standard forautomobile diesel fuels basically—the density was0.8489g·cm-3, the sulfur content was248μg·g-1, the nitrogen content was10μg·g-1and the cetane number was about38; and theproperties of the hydrotreated gas oil can meet the requirement of FCC feed or hydrocrackingfeed—the density was0.8827g·cm-3, the sulfur content was2450μg·g-1, the nitrogen contentwas120μg·g-1and the carbon residue value was0.05%. It was a suitable operation conditionfor mixed oil hydrotreating.