IE37159B1 - Fluid catalyst regeneration process with substantially complete combustion of carbon monoxide - Google Patents

Abstract

1417980 Catalyst regeneration STANDARD OIL CO 14 Nov 1972 [30 Nov 1971 12 June 1972] 52560/72 Headings B1E and B1F [Also in Division C5] In a cracking process of the kind in which a fluidizable zeolite catalysts deactivated by coke deposits is withdrawn from the cracking zone, stripped of volatiles, regenerated and returned to the cracking zone, the regeneration is carried out in the presence of an excess of oxygen, so that nearly all of the coke is burned to CO 2 . As shown, the regenerator 1 comprises a lower section 6 containing a fluidized bed of catalyst particles and an upper section 15. Spent catalyst enters by lines 2 and 3 and is fluidized by air from line 8 and ring 11. The gas passing to upper section 15 still contains some CO, which is there burned to CO 2 . Catalyst from the bed is raised in the eductor tube 40 by a stream of air, steam or other gas from line 42 into the upper section 15, where it absorbs most of the heat of this combustion and falls back into the bed. Regenerated catalyst is withdrawn by standpipes 34 and 35, and spent gas containing very little CO by line 33. Temperatures can be raised, if necessary, e.g. on startup, by introducing an oil fuel through line 12. The upper zone can be cooled if necessary by steam from pod 49 and ring 53, or by a water spray (not shown). In another embodiment (Fig. 2, not shown), the eductor (40) is omitted and the fluidizing gas is relied on to carry enough of the catalyst into the upper section. Spent catalyst is in this case admitted through the side of the vessel, just below the top of the fluidised bed. The catalyst may comprise a mixture of silica, alumina and zeolite. Suitable times, temperatures and catalyst compositions are described. [GB1417980A]