Identification of Metal Contaminants on FCC Catalyst.

Abstract

FCC Catalyst deactivation is a major source of expense in the refining industry. Of concern is the deposition of contaminant metals onto the catalyst particles, leading to premature deactivation. Samples of used catalyst were collected from a working refinery using the standard sampling ports. These samples were subjected to surface examination by Scanning Electron Microscope, and to X-ray Micro Analysis to determine elementary composition of key metals. Particle mapping was conducted to obtain cross sectional composition of both used and fresh catalyst. It was found that metals preferentially deposit onto the outside of the catalyst particles, presumably causing premature de-activation to occur. Although the particles are found in a high attrition environment, the metal deposits formed a rough outer surface on the particle. Mild attrition of these particles was found to remove this outside layer of material and help to restore the original chemical make up of the particles surface. This work has shown how refineries can investigate metal deposition onto particles surfaces which will help them better manage FCCU catalyst usage.