Patent ID: 6034019
Filing Date: 2000-03-07
Classification: B01J

Abstract:
A process for regenerating a deactivated noble metal-containing supported catalyst which contains iron impurities and coke and wherein iron contamination of the catalyst during regeneration is diminished comprising:(a) heating said deactivated catalyst in an oxygen-containing atmosphere at a flame front temperature in the range of about 375.degree. C. to about 550.degree. C. for a period of time sufficient to remove a substantial portion of said coke from said catalyst to oxidize said noble metal and to convert iron contaminants present in said catalyst into predominantly Fe.sub.2 O.sub.3 ;(b) contacting said oxidized catalyst with an atmosphere free of elemental oxygen and containing a reducing gas at a temperature and for a period of time sufficient to substantially reduce said noble metal oxide and to reduce said Fe.sub.2 O.sub.3 to predominantly iron metal;(c) contacting said reduced catalyst with a gas stream comprising steam under conditions of temperature and for a period of time sufficient to oxidize said iron metal to predominantly Fe.sub.3 O.sub.4 without substantially oxidizing said reduced noble metal; and(d) contacting the catalyst from step (c) at an elevated temperature with a gas stream comprising a halide-providing compound which stream is essentially free of elemental oxygen and elemental halogen and which stream contains from 0.5 to less than 6 vol % added water for a period of time sufficient to provide at least about 1.3 wt % of halide to said catalyst.