Frangible catalyst pretreatment method for use in hydrocarbon

Abstract

Activated bauxite particulate material having usual nominal particle size range of 20-50 mesh (U.S. Sieve Series) is treated by fluidization in an upflowing gas so as to attrite the particles and stabilize the particle shape and size, thereby making the catalyst more uniform in shape and resistent to attrition in subsequent ebullated bed reactor operations. The treated activated bauxite catalyst material is then rescreened to provide a narrower differential size range having a particle equivalent diameter ratio range for large to small particles of about 1.4-2.0, and a preferred 20-30 mesh (U.S. Sieve Series) particle size range. The selected pretreated catalyst is then introduced into the ebullated bed reactor of a hydrodemetallization process for hydrocarbon feedstocks containing high metals concentration. Use of such pretreated bauxite catalyst particles results in improved reactor fluidization operations and less catalyst loss by attrition and carryover of fines from the reactor, and achieves improved results of 60-70 W % demetallization and 50-55 V % hydroconversion of the 975.degree. F..sup.30 fraction to lower boiling hydrocarbon products in a single stage operation.