Presented by Darius Morris, Stanford Synchrotron Radiation Lightsource
Fluid catalytic cracking (FCC) is a refining process for converting large and/or heavy molecules of oil feedstock into smaller and lighter hydrocarbons such as gasoline. During the cracking process, metal contaminants from the oil feedstock deactivate and restrict access into the catalyst particle, thus reducing the yield of gasoline byproducts. Full-field transmission X-ray microscopy (TXM) has been used to determine the 3D composition and structure of an equilibrated (spent) FCC particle in a fast, noninvasive manner. Using X-ray absorption mosaic imaging with multiple fields of view (FOV), 3D tomography has been reconstructed and used to visualize macroscopic highways for molecular transport throughout the FCC particle. We have mapped spatial distributions of Ni and Fe using multiple-energy tomography at the respective x-ray absorption K-edges, and correlated this distribution with morphology, porosity, and permeability of the FCC catalyst. The contrasting distributions of Fe and Ni were correlated with spatial heterogeneities in porosity and permeability, facilitating an investigation of contamination within an equilibrated FCC particle.
