Patent ID: 7915191

Claim:
A method for regenerating a catalyst used in an FCC unit, comprising: providing a spent catalyst into an upper portion of a regenerator; maintaining a calcination phase, a gasification phase, and a combustion phase of fluidized catalyst in said regenerator, wherein said gasification phase resides below said calcination phase and above said combustion phase; introducing an oxygen-containing gas into a bottom portion of said regenerator; combusting carbon on partially regenerated catalyst from said gasification phase with said oxygen-containing gas in said combustion phase to produce fully regenerated catalyst and a combustion flue gas comprising carbon dioxide and unreacted oxygen which travel upwardly into said gasification phase; reacting carbon on stripped catalyst from said calcination phase with carbon dioxide and unreacted oxygen in said combustion flue gas from said combustion phase in said gasification phase to produce said partially regenerated catalyst and a gasification flue gas rich in carbon monoxide which travels upwardly into said calcination phase; calcining said spent catalyst with carbon monoxide in said gasification flue gas from said gasification phase in said calcination phase to produce said stripped catalyst and calcination flue gas; withdrawing said fully regenerated catalyst through a line connected to a lower portion of said regenerator; and discharging said calcination flue gas through a line connected to an upper portion of said regenerator, said calcination flue gas having a heat of combustion of at least 1860 kJ/m 3 .