New Catalysts from Spent Catalysts - Spent Hydroprocessing Catalysts - page 242

Figure 9.8: Activity comparison between reprocessed and reference (commercial) catalyst: (a)
hydrodesulfurization (HDS) activity; (b) hydrodevanadization (HDV) activity [From ref. 522 .
Reprinted with permission].
sample were mixed with boehmite and extruded. The surface area and pore volume of the
reprocessed catalysts shown in Fig. 9.9 [524] indicate a beneficial effect of hydrothermal
treatment. For example, for the reprocessed catalyst containing 40% of spent catalyst, surface
area and pore volume increased from 70 to 144 m 2 /g and from 0.27 to 0.39 mL/g, respectively.
The HDS and HDM activities determined under identical conditions as above [9,524,525]
shown in Fig. 9.10 [524] confirmed that the additional enhancement in the catalyst activity
reprocessed catalysts can be achieved by a hydrothermal treatment of spent catalyst.
Figure 9.9: Effect of hydrothermal treatment and content of spent catalyst on surface area and
pore volume of reprocessed catalyst [From ref. 524 . Reprinted with permission].