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we have problem in our FCC unit where the temperature of the dilute at regenerator is higher than the temperature of flue gas, and we have abnormal loss in catalyst...can anyone help?
 
Answers
28/12/2010 A: Gareth Richardson, Murphy Oil Corp, Gareth_Richardson@murphyoilcorp.com
if your bed temperature distributions is good it may be worth while checking if you have a flue gas quench gun passing either steam of BFW?
09/03/2010 A: Lefter Rinaldo, Netcodietsmann, dumitrurinaldo@yahoo.com
Abnormal temperature profile in regenerator is due to excess air into regenerator. Concernic catalyst loss, if the parameters of regenerator are in range, failure of the cyclones may be responsible. However, inspection of the regenerator internals is required.
03/07/2009 A: Saugata Palit, Intercat India Ltd, spalit@intercatinc.com
If yours is a full burn unit, there is every possibility of dilute bed temperature to be higher than dense and flue gas temperature. If it is a two stage regen, then the phenomenon may be observed in second stage regen, which is in total burning mode. This is happens due to catalyst and air distribution problems at localized areas of the regen.
As far as the catalyst losses are concerned, that may due to several other reasons. it may be due to improper fluidization, damaged cyclones or excessive catalyst attrition in the system
21/11/2007 A: Ziad S Jawad, Technip Stone & Webster Process Technology, zjawad@technip.com
Is this a full burn unit? It sounds like you have maldistribution in your regenerator dense bed. You may be in full burn in some parts of your bed and partial burn in others. When these gasses mix at the cyclone inlets there is a wide variation of temperatures. The afterburn in some portions of the dilute phase may be affecting cyclone performance. The mixture of all the combustion by products in the flue gas line may be higher or lower than what the limited dilute phase thermocouples predict.
I suggest troubleshooting spent catalyst and combustion distribution in the regenerator. Another useful piece of information is a dilute phase temperature distribution.
16/11/2007 A: Saidulu G, IOCL, saidulug@iocrd.co.in
Check your delta P across your cyclone system (diff between Rg and Fg pressure). If it is lower, you can expect some mechanical problem like weld failure in cyclone system.
16/10/2007 A: SImone Robinson, Tube Tech International Ltd, simone@tubetech.com
Is the regenerator fouled at all? If so I am sure we could help.
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