Abstract: In view of the serious iron poisoning of the catalysts in heavy oil catalytic cracking unit of a domestic refinery due to influence of processing heavy, inferior feedstock and bottom oil, the typical iron poisoning phenomenon in industrial production was analyzed from the property of equilibrium catalyst(E-cats) and products distribution, and the iron content of the E-cats was analyzed. The results showed that a high amount of iron pollution would decrease the bulk density of E-cats, and the correlation between iron content and the specific surface area and pore volume of E-cats was poor. It was found that the iron poisoning of catalyst could increase the yield of slurry and dry gas and decrease the yield of light oil, and that there were many depressions and grooves on the surface of the iron poisoning E-cats. The iron content in the depressions was relatively high, and the iron was mainly concentrated on the outer surface of the catalyst particles. Based on the above research results, some suggestions were provided for the device to process high-iron content feedstock. Among them, the use of a catalyst with better iron resistance can greatly solve the problem of iron poisoning.

Key words: fluid catalytic cracking, Iron contamination, catalyst