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U.S. Department of Energy
Office of Scientific and Technical Information

Reactivation of iridium-containing catalysts

Patent ·
OSTI ID:6477958
A process wherein a coked, deactivated iridium-containing catalyst can be reactivated in a sequence of burn steps, inclusive of a low temperature primary burn step and a subsequent high temperature burn step. In the low temperature primary burn step the chloride level of the catalyst is raised and the catalyst passivated by contact with a hydrogen chloride containing gas, and coke is then burned from the catalyst by contact with a gas which contains hydrogen chloride at level sufficient to suppress iridium agglomeration at a level of oxygen providing burn temperatures which do not exceed about 425/sup 0/ C., this being sufficient to remove a preponderance of the coke without agglomeration of the iridium component. In a high temperature secondary burn step the catalyst is subjected to chlorination step wherein the catalyst is contacted with a hydrogen chloride containing gas sufficient to redisperse any agglomerated iridium, if any, produced during the low temperature primary burn, and raise the chloride level of the catalyst to a yet higher level for suppression of iridium agglomeration at higher temperature than 425/sup 0/ C., residual coke is then burned from said catalyst by contact with a gas which contains hydrogen chloride at level sufficient to suppress iridium agglomeration at a level of oxygen sufficient to provide temperatures greater than 425/sup 0/ C., sufficient to burn residual coke from the catalyst. The high chloride catalyst can then be stripped with steam, or steam and hydrogen chloride to reduce the level of chloride.
Assignee:
Exxon Research and Engineering Co.
Patent Number(s):
US 4517076
OSTI ID:
6477958
Country of Publication:
United States
Language:
English