Regeneration and reactivation of reforming catalysts avoiding iron scale

Abstract

Improvements in a reforming process for the regeneration and reactivation of a bed of a reforming catalyst, notably an iridium-containing catalyst, coked and catalytically deactivated during the on-oil portion of a reforming cycle. The reactor containing the catalyst is contained in a multi-reactor unit, the individual reactors of which are connected in series via suitable piping and valving. The reactor can be alternately manifolded with production facilities during the on-oil portion of the operating cycle during which period the catalyst of said reactor becomes coked, and can be manifolded alone or with other reactors with a ferrous metal regeneration circuit during the catalyst regeneration and reactivation portion of an operating cycle during which period the catalyst is regenerated and reactivated. In the regeneration and reactivation of the coked catalyst the sequence of process steps include (a) an oxidation step and subsequent reduction step, or (b) a reduction step and subsequent oxidation step, to remove coke and redisperse the iridium component of the catalyst of said reactor. Iron scale carryover from the regeneration circuit to the catalyst of said reactor is drastically reduced by by-passing said reactor during the periods of transition from the (a) oxidation step to the reduction step, or (b) from the reduction step to the oxidation step by closing off the manifold connection between the regeneration circuit and the said reactor. Loss of catalyst activity due to iron scale carryover to the catalyst of said reactor is thus suppressed.