Method for suppressing the dehydrogenation activity of deposited metals on inert solids in heavy oil pretreatment

摘要

Contaminant metals in hydrocarbon oils such as nickel, vanadium and iron deposit on inert sorbents during pretreatment of the oils in a fluidized reactor-regenerator system, and catalyze dehydrogenation reactions contributing to excessive coke and gas make. The dehydrogenation activity of the said contaminant metals is suppressed by depositing minor amounts of a bismuth-containing passivating agent on the inert solids, desirably, at a weight ratio of bismuth to nickel equivalents (nickel+0.2 vanadium+0.1 iron) of about 0.01:1 to about 1:1. The passivating agent can consist of mixtures of compounds of bismuth and antimony, and bismuth and tin, with the weight ratio of bismuth to antimony in the range of about 0.01:1 to about 100:1, and weight ratio of bismuth to tin in the range of about 0.01:1 to about 100:1.