HYDRODEMETALLISATION OF RESIDUAL OIL WITH CATALYSTS USING FIBRILLAR ALUMINA AS CARRIER MATERIAL

Hydroprocessing catalysts were prepared using fibrillar aluminas as ca rrier materials and sulphides of nickel and molybdenum as active subst ances. The fibrillar aluminas were obtained from fibrillar boehmite sa mples prepared at three different synthesis conditions resulting in di fferent fibril sizes. After extrudation and deposition of metals, cata lysts combining large surface areas with large average pore diameters were obtained. The catalysts were tested for hydrodemetallisation of a n atmospheric residue and the results were compared with those obtaine d for a commercial reference catalyst with a similar loading of nickel and molybdenum. Two of the catalysts prepared using fibrillar alumina as carrier material were more active than the commercial catalyst. Th e third catalyst containing the largest alumina fibrils was inferior t o the other catalysts in all respects. Catalyst deactivation was inves tigated in a long-term hydroprocessing experiment using a heavy vacuum residue containing large amounts of metals as a feed oil, The catalys t prepared using fibrillar alumina used in this test showed a constant level of hydrodemetallisation even after 500 h on stream whereas the reference catalyst was completely deactivated after 350 h.