| abstract |
An ebullated bed hydroprocessing system, and also a method for upgrading an existing ebullated bed hydroprocessing system, involves introducing a colloidal or molecular catalyst, or a catalyst precursor capable of forming the colloidal or molecular catalyst, into an ebullated bed reactor. The colloidal or molecular catalyst is formed by intimately mixing a catalyst precursor into a heavy oil feedstock and raising the temperature of the feedstock to above the decomposition temperature of the catalyst precursor to form the colloidal or molecular catalyst in situ. The improved ebullated bed hydroprocessing system includes at least one ebullated bed reactor that employs both a porous supported catalyst and the colloidal or molecular catalyst to catalyze hydroprocessing reactions involving the feedstock and hydrogen. The colloidal or molecular catalyst provides catalyst in what would otherwise constitute catalyst free zones within the ebullated bed hydroprocessing system. Asphaltene or other hydrocarbon molecules too large to diffuse into the pores of the supported catalyst can be upgraded by the colloidal or molecular catalyst. A slurry phase reactor may be positioned upstream from one or more ebullated bed reactors or converted from an existing ebullated bed reactor. |