Catalytic reforming regeneration

Catalytic Reforming Heater stack gas (CO, SO, NO, HCs and PM), fugitive emissions (hydrocarbons) and catalyst regeneration (CO, NO, SO,). 

The process consists of a reactor section, continuous catalyst regeneration unit (CCR), and product recovery section. Stacked radial-flow reactors are used to minimize pressure drop and to facilitate catalyst recirculation to and from the CCR. The reactor feed consists solely of LPG plus the recycle of unconverted feed components no hydrogen is recycled. The liquid product contains about 92 wt% benzene, toluene, and xylenes (BTX) (Figure 6-7), with a balance of Cg aromatics and a low nonaromatic content. Therefore, the product could be used directly for the recovery of benzene by fractional distillation (without the extraction step needed in catalytic reforming). 

Fluid Hydroforming An early catalytic reforming process in which the catalyst was used in a continuously regenerated fluidized bed. Developed by the MW Kellogg Company. 

Ultraforming A catalytic reforming process developed by Standard Oil of Indiana and licensed by Amoco Oil Company. The catalyst contains platinum and rhenium, contained in a swing reactor - one that can be isolated from the rest of the equipment so that the catalyst can be regenerated while the unit is operating. The first unit was commissioned in 1954. 

Regeneration is a critical step in catalytic reformer operation to regain activity, selectivity and stability of deactivated catalyst. Regeneration procedures and capabilities are dependent on the causes of deactivation. The procedures are proprietary in nature and supplied by catalyst vendors or process licensors The catalyst deactivated by coke can be easily regenerated to restore it s activity, Modified methods are adopted when catalyst had suffered from sulfur or water upset. It is important to emphasize that on line catalyst samplers are good tools to know the state of catalyst, causes of deactivation and help in improving operational and regeneration effkiency[ll]. There are no samplers installed in the reformer under discussion... 

It follows that regeneration may consist of either (i) removal of IS sometimes poisons, most often inhibitors or fouling agents, e.g., coke (hydrogenation catalysts, e.g., selective hydrogenation of pyrolysis gasoline) or (ii) redispersion of the active species (platinum catalysts) or (iii) both (hydrodesulfurization or catalytic reforming catalysts). 

Fig. 18.17. Catalytic reforming—Axens. Includes moving-bed reactors (1,2,3) and regenerator (4). (Source Hydrocarbon Processing, 2004 Refining Process Handbook. CD-ROM. September 2004 copyright Gulf Publishing Co., all rights reserved.)...

Because hydrogen is used in the reforming reaction, materials must be selected according to API 941, except that C-V Mo should not be used (i.e., the minimum alloy for hydrogen service should be lCr-M Mo). As mentioned previously, this is because of C- Mo failures in catalytic reformers that some refiners have related to the catalytic reformer process regeneration. When selecting furnace tubes, for example, it is important to select the steel with the hydrogen resistance based on the metal temperature,... 

Regeneration of Catalytic reforming units which includes some catalyst with high levels of residual graphitic carbon levels and high density "collapsed" particles. 

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