Fluidizable composition for catalytic cracking.

摘要

A fluidizable catalyst composition for fluid catalytic cracking of hydrocarbon fractions, the composition comprising (a) zeolitic particles of relatively high catalytic activity and comprising Y-faujasite in a matrix containing at least a portion of silica-alumina and (b) additive particles which are relatively inert towards catalytic cracking and comprise vanadium immobilization agent selected from calcium and rare earth oxides and precursors thereof carried by microspheres of a total BET surface area of less than 20 m<2>/g and comprising kaolin which has been calcined through its exotherm, the zeolitic particles (after steam treatment in a fluidized bed reactor at 1450 DEG F for four hours using 90 volume % flowing steam plus 10% air atmosphere) displaying a weight percent conversion of at least 70% when tested using the feedstock of Table III in the microactivity test of ASTM D.3907-80, the reactor being operated at 910 DEG F, the catalyst to oil weight ration being 5, and the weight hourly space velocity being 15h<-><1>. The composition resists degeneration due to vanadium contaminant in the hydrocarbon feed.