Method of regenerating a fixed bed catalyst

Claim 1

IN THE REMOVAL OF CARBONACEOUS DEPOSITS FROM SOLID CONTACT MATERIAL DISPOSED IN A FIXED BED, BY COMBUSTION WITH AN OXYGEN-CONTAINING GAS, WHEREIN SAID GAS IS INTRODUCED AT ONE END OF THE BED AT A TEMPERATURE SUFFICIENT TO AT LEAST INITIATE COMBUSTION AND IS REMOVED IN A SPENT CONDITION FROM THE OTHER END OF THE BED, AND WHEREIN A ZONE CONTAINING RESIDUAL UNCOMBUSTED CARBONACEOUS DEPOSIT REMAINS IN SAID BED NEAR SAID OTHER END AT THE TIME WHEN OXYGEN APPEARS IN THE EFFLUENT, THE METHOD OF EFFECTING SUBSTANTIALLY UNIFORM REMOVAL OF CARBON THROUGHOUT THE BED OF CONTACT MATERIAL WHICH COMPRISES INTRODUCING A STREAM OF OXYGEN-CONTAINING GAS INTO ONE END OF THE BED AND PASSING SAID GAS LONGITUDINALLY THERETHROUGH UNDER COMBUSTION CONDITIONS UNTIL FREE OXYGEN BEGINS TO APPEAR IN THE EFFLUENT, AND THEREAFTER INTRODUCING AN ADDITIONAL STREAM OF OXYGEN-CONTAINING GAS UNDER COMBUSTION CONDITIONS DIRECTLY INTO SAID ZONE OF UNCOMBUSTED CARBON, AND CONTINUING THE FLOW OF BOTH STREAMS UNTIL UNIFORM REACTIVATION IS SUBSTANTIALLY COMPLETE.