ABSTRACT
A number of hydrotreating catalysis are used in commercial heavy oil upgrading facilities. One of these, a CoO/M0O3/Al2O3 catalyst has been evaluated in a pilot plant CSTR for Tar-Sands Bitumen upgrading. Following its use in a test of 200 hours duration, the catalyst was removed, de-oiled, regenerated by air-calcination to remove the coke, and then re-tested. Samples of the coked, fresh and regenerated catalyst were each examined using surface analytical techniques. ESCAand SIMS analysis of the coked and regenerated catalyst samples show, as expected, significant contamination of the catalyst with Ni and V. In addition, the SIMS analysis clearly reveals that the edges of the catalyst pellets are rich in Ca,Mg and Fe while the Ni, V and coke are evenly distributed. Regeneration of the catalyst by calcination removes the carbonaceous material but appears not to change the distribution of the metal contaminants. Retesting of the regenerated catalyst shows a performance similar to that of the fresh catalyst. These data serve to support the view that catalyst deactivation during early use is not due to the ‘skin’ of Ca and Mg on the pellets but rather via the poisoning of active sites by carbonaceous species.176
