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Monitoring fluid cracking catalyst deactivation profile by equilibrium catalyst separation

Conference · · American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States)
OSTI ID:7195192
; ;  [1]; ; ;  [2]
  1. Amoco Oil Co., Naperville, IL (United States)
  2. Amoco Corp., Naperville, IL (United States)

Both the results of cumene cracking investigations on regenerated fractions and of residual coke determinations on precoked fractions indicate that relatively high activity is exhibited by only the lightest/youngest fractions. It follows that a disproportionate share of catalyst activity is associated with the youngest 15% of the catalyst inventory. The deactivation profile exhibited by the majority of this equilibrium catalyst is remarkably similar to that resulting from increasingly severe laboratory steam deactivations. Dealumination is rapid, crystallinity retention is 70% or more, and there is little loss of matrix surface area. The wide range of steaming temperatures necessary to reproduce the equilibrium catalyst deactivation profile indicates that improved aging procedures will involve the blending of catalyst portions steamed at different temperatures. The results of analytical electron microscopy investigations shed new light on the mechanism of high temperature steam destruction of USY zeolite in the FCU. Lattice imaging, together with compositional analyses, demonstrates that the crystalline regions found in a young fraction (B) are much more extensive than those found in an old fraction (F). The intimate mixture of small USY crystallites and collapsed zeolite found within characteristic amorphous regions exhibited by the older fractions (F) indicates that high temperature steam destruction of zeolite in the FCU is accompanied by extensive crystallite fracturing. The result that only the youngest (most active) fractions are density-separated on the basis of activity for coking from isobutene has led to new insight which provides a sound basis for future application of float-sink density separation techniques on equilibrium catalysts containing high proportions of zeolite.

OSTI ID:
7195192
Report Number(s):
CONF-900802--
Journal Information:
American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States), Journal Name: American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States) Vol. 35:4; ISSN 0569-3799; ISSN ACPCA
Country of Publication:
United States
Language:
English