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What are generally the end of run characteristics of a catalyst? What are the signs indicating the need for catalyst regeneration?
 
Answers
01/05/2018 A: Krishna Rao Pulugurti, Retired/Consultant, pkrao2012@yahoo.com
Reformate yield would be low even at high catalyst temperatures. Aromatics formation would be less.
01/05/2018 A: Virendra Kapoor, Petroleum Refining Consultants, vkkapoor9@yahoo.com
Depends on process and cat. Important physico -chemical characteristics, products qualities and yields provide guide lines. Selectivity and activities changes, limitations of the furnaces, compressors and.operating parameters also play roles.
Techno-economics dictates the end of cycle length & regeneration beside other logistics.
30/04/2018 A: Steve Mayo, Eurecat US Inc, smayo@eurecat.com
End of run (EOR) is defined as the point in time when the unit/catalyst cannot meet one or more required product properties at typical throughput. Most commonly EOR is set by metallurgical temperature limits of reactor, when reactor temperature can no longer be increased to compensate for loss of catalyst activity. In some cases other product properties (color, density, aromatic content, etc) may constrain operating temperature below unit metallurgical limits. Units with very exothermic reactions may not be safe to operate over a certain temperature.
Catalyst deactivation rate can be determined by normalizing operating data with kinetics for the unit. Deactivation rate is typically linear for most of a given cycle though non-linear behavior may occur at the beginning and sometimes the end of cycle. Projecting future reactor temperature with the deactivation rate provides a reliable indicator of when EOR conditions will be reached and the catalyst will need regeneration or replacement.
30/04/2018 A: Muhammad Akhtar, Orpic, mbadgk@gmail.com
You have not mentioned which unit catalyst you are talking about.
But in general, if you can not take the sample of the catalyst online than following are the parameters that can serve as the basis for decision (especially for catalytic reforming unit)
1) Loss of conversion at 100% load.
2) Reaching to End of Run temperature for maintaining the same conversion rate
3) decreased hydrogen purity
4) Increased cracked product like Fuel gas and LPG generation.
More information can be given based on the specific information required.
30/04/2018 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
For the reforming catalyst to maintain its activity, there needs to be a certain level of water and a certain level of chloride on the catalyst itself.
The catalyst activity declines during a run. When to regenerate can be determined by calculation using a software program available from your process licensor. Many factors are considered in the calculation. Some of them are:
• Value of the products vs the value of the feed
• Rate of decline of the calculated conversion of naphthenes to aromatics
• Operating costs
• All costs associated with a downtime duration
• Whether or not the process unit has surplus capacity that can be used to slowly run feedstock saved during downtime along with regular feed. This is called “catch-up capacity.”
Before computers were available, we would make that optimization calculation by hand.
If you want to know how a catalyst pellet changes, the company who reconditions your catalyst can tell you what they look for in the reconditioning process results.