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I want to know the effect of excess air on dilute phase temperature. Regenrator (Full combustion) is operating at 2% excess oxygen. If excess oxygen is increased to 5% for some reason, what is the effect on dilute phase temperature with same cat/oil ratio and cat circulation rate.
 
Answers
17/09/2020 A: Indrajit Karmakar, IOCL, indrajit_karmakar@yahoo.co.in
In full burn mode, there will be not much CO left above the dense phase for burning, so the temperature rise may be minimal. Excess O2 may marginally reduce the dilute bed temperature if excessive. If it is done for a constant catalyst circulation condition where the dense bed catalyst temperature seems to be unchanged. Excess O2 will increase flue gas flow through the DDSV/orifice chamber, increasing the back pressure to the regenerators.
05/08/2013 A: Prabhat Choudhary , IOCL, prabhatchoudhary26@gmail.com
Temp will rise and will depend upon partial or full burn. This is the case of After burning which is very common in RFCC unit.
18/07/2013 A: Bob Kalaria, KBR, bhavdip.kalaria@kbr.com
If you increase the excess O2, the additional amount of O2 will escape the regenerator bed. In the dilute phase, it may combine with escaped CO to form CO2. This may increase the dilute phase temperature slightly.
Since the regenerator is already operating in full combustion mode, only limited amount of CO will be left in the dilute phase hence the temperature increase will be minimal.