High Quality Diesel by Hydrotreating Gas Oil Over Modified Titania - Supported Nimo Catalysts.

Abstract

In this work, methods for preparing alumina-titania and ceria-titania mixed oxide supports were studied. In one method, alumina or ceria were precipitated on the surface of a commercial titanium oxide,. In the second method, alumina or ceria were impregnated on the surface of titania followed by drying and calcination as with the first method .The metal oxide couples used in this study contains NiO and MoO 3 . In this study,the catalyst content of NiO is3 wt% while MoO 3 is8 wt.% while 89 wt.% is the support material. Surface area and pore volume measurements for the supports and catalysts were determined. Al, Ce, Ni and Mo contents as well as the coke percentage the spent catalyst were determined by chemical analysis. Characterization of the prepared support samples have been studied by DTA and XRD. The HDS activities of the prepared catalyst samples have been studied in comparison with titania and alumina catalysts. Two types of catalytic tests were used.One type of measurement was a screening test using the pulse technique while the second type was focused on studying the effect of important process variables as reaction temperature, hydrogen pressure and liquid hourly space velocity (LHSV) on the extent of HDS of gas oil (GO) feadstock and simultaneous HDS and HDN of GO + Pyridine on the selected screened catalysts by using the continuous flow highpressure fixed bed cata -test unit. The results revealed that these catalysts are much more active than the conventional NiMo/Al 2 O 3 catalysts on HDS and HDN reactions. The results revealed that these catalysts are much more active than the conventional NiMo/Al 2 O 3 catalysts on HDS and HDN reactions.They also demonstrate high aromatic saturation capabilities. The inhibiting effect of pyridine on gas oil HDS was found to be similar for all catalysts, i.e.: was independent on the support composition.In general, diesel fuel quality improved as the temperature and pressure increased or space velocity decreased.