Research continuous catalyst regeneration

Tire decline in catalyst activity seen in some continuous photocatalytic systems has prompted researchers to examine methods of restoring activity to used photocatalysts. Because the decline in catalyst activity is often attributed to the accumulation of recalcitrant intermediates or by-products on the catalyst surface, most catalyst regeneration techniques focus on the removal of these presumed species. Two such methods, thermal regeneration and photocatalytic regeneration, have been examined for use in association with the photocatalytic oxidation of aromatic contaminants. 

The use of a fluidized-bed reactor has a number of advantages in the MTO process. The moving bed of catalyst allows the continuous movement of a portion of used catalyst to a separate regeneration vessel for removal of coke deposits by burning with air. Thus, a constant catalyst activity and product composition can be maintained in the MTO reactor. Figure 12.10 demonstrates the stability of a 90 day operation in the fluidized-bed MTO demonstration unit at the Norsk Hydro Research Center in Porsgrunn, Norway. A fluidized-bed reactor also allows for... 

In the fluid-catalyst process, finely divided catalyst powder is continuously circulated from reactor to regenerator and back again without mechanical means. The fluid process was originated by the Standard Oil Development Company, the research organization of the Standard Oil Company of New Jersey, in collaboration with The M. W. Kellogg Company and Standard Oil Company (Indiana). Other companies participating in the development were Anglo-Iranian Oil Company, Ltd., Shell Oil Company, The Texas Company, and Universal Oil Products Company. This process was first announced in 1941 (48). 

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