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What would be the effect of fluctuation in regeneration gas flow in UOP Cyclemax Regenerator if my flow is having variation by 5-8%?? Will there be any effect on catalyst coke burning? What could be the reason for flow variation?
 
Answers
09/11/2018 A: Patrick Bullen, UOP, patrick.bullen@uop.com
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07/11/2018 A: Peter Marsh, XBP Refining Consultants Ltd, peter.marsh@xbprefining.co.uk
If the regeneration gas flow is truly fluctuating, you will see this on the amps drawn by the blower motor and in corresponding temperature instability in the burn zone. It is more likely that there is a problem with the flow measurement. The regeneration gas flow is measured via differential pressure across the regeneration gas cooler and the pressure taps are nitrogen purged. Check the nitrogen purge is in commission to the upstream (HP) and downstream (LP) pressure connections and that the purge flows to each are correctly set. If you are operating in a cold climate and/or the thermal insulation around the pressure connections has been damaged or removed you may have chloride salt deposition in the pressure taps.
There will be no impact on available coke burn capacity if the problem is simply a consequence of errors in regeneration gas flow measurement. However, if you are seeing a permanent reduction in regeneration gas flow of 5 - 8%, this will cause a loss of coke burn capacity and you will see a shift in the burn profile and differential pressure across the regeneration gas circuit. The most likely cause for this is plugging of the regenerator screens. If the source of the plugging is not identified and eliminated this will eventually require a shutdown of the Cyclemax Regenerator system for inner/outer screen cleaning.
07/11/2018 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Maybe a control valve is sticking, has no positioner and needs one. Is the pressure oscillating, too?