No abstract

A series of aluminum borate with various boria content were prepared. These materials were used as the supports of Co-Mo catalysts. They were characterized with respect to surface area, pore volume, and pore size distribution. The temperature programmed reduction method was used to monitor molybdenum oxide-support interaction. The results showed that the addition of boria concentration (2, 4, and 6 wt%) decreases the reducibility of the catalyst, reduction peak increase with increasing B 2 O 3 content. Hydrodesulfurization of atmospheric gas oil was carried out over these presulfided catalysts in a bench-scale cata-test unit at 320-360 ı C and LHSV from 1 to 3 h 1 . Hydrogen pressure and H 2 /HC feed ratio were kept constant at 4 MPa and 300 l/l, respectively. All Co-Mo-/AB catalysts are much more active than the conventional Co-Mo/Al 2 O 3 catalyst on hydrodesulfurization reactions. The dispersion of the active sulfide phase of Co-Mo/Al 2 O 3 catalyst is increased by the incorporation of adequate boria content. An optimum B 2 O 3 content, which gives the highest activity, was found in the vicinity of 4 wt%.

The deactivation of commercial NiMo/SiO 2 À Al 2 O 3 hydrocracking catalysts under fast deactivation procedures were investigated. Two blends of atmospheric fuel oil with other heavy oils in different ratios (0-100 %) were utilized as feedstock. The protocol was used to investigate the effect of blend chemical composition on coke and metal deposition. The produced oils and spent catalysts were characterized by several techniques. The results showed that utilizing blend 1 has resulted in a higher coke formation during hydrocracking than blend 2. Furthermore, the catalyst textural properties were declined if compared to the case of blend 2 utilization. The activity was illustrated in the basis of heterocompounds, asphaltene and wax content. The time on stream investigations (4-20 h) revealed the increase in coke formation and dramatic decrease in catalyst's textures along first 4 hours then leveled off. Regeneration catalyst at 450 °C for 12 h the catalyst properties were recovered.