Abstract: Disclosed are a mixed catalyst comprising catalyst A and catalyst B mixed in a volume ratio ranging from 1:0.1 to 1:10, heavy crude oil ebullated-bed hydrotreating systems comprising at least one ebullated-bed reactor comprising the mixed catalyst, and heavy crude oil ebullated-bed hydrotreating processes comprising: introducing heavy crude oil and hydrogen into at least one ebullated-bed reactor, reacting the heavy crude oil and the hydrogen with the mixed catalyst in the at least one ebullated-bed reactor to produce reaction products; and discharging the reaction products from the top of the at least one ebullated-bed reactor.

Abstract: A catalyst for hydrodemetalization of heavy oil, especially residuum oil, and a process for preparing the same, wherein said catalyst comprises the metal elements of Groups VIII and/or VIB as active components supported on an alumina carrier having large pores. The total pore volume of said carrier is in the range of 0.80˜1.20 ml/g (by mercury porosimetry method), the specific surface area in the range of 110˜200 m2/g, the peak pore diameter in the range of 15˜20 nm, and the bulk density in the range of 0.50˜0.60 g/ml. In the process of the invention, a physical pore-enlarging agent and a chemical pore-enlarging agent are added simultaneously during the mixing of the pseudoboehmite to a plastic mass, then extruding, drying, calcining, the carrier is obtained, then impregnating with active components by spraying onto the carrier, after drying and calcining, the catalyst is obtained.