| abstract |
A two-stage hydrodesulfurization process for a 65 to 80 percent desulfurization of a high metal content residuum, such as those obtained from Venezuela, in which the contact solids activity in both stages is maintained at an equilibrium level by constant replacement of the contact solids in both stages. The first stage contains a porous alumina solids contact material activated with at least one promoter oxide selected from Fe2O3, TiO2 and SiO2, which has as its primary purpose the removal of vanadium and nickel from the feed material. However, the treatment of the feed in the first stage was found to improve the second stage performance by a factor greater than the amount of metals removed. The second stage contains a highly active desulfurization catalyst of limited porosity. |