We’re struggling to keep our FCC dust emissions below compliance limit.
Our ESP is undersized and it looks like its performance got worse in the first months of operation after turnaround.
In particular ESP voltage decreased by 20% during the first 3 months of operation. At the same time:
– ESP inlet temperature increased due to rapid fouling of Flue Gas Cooler (now 350-370 DegC vs 250 DegC at start of run).
– SOx decreased by a factor 3 due to injection of SOx reduction additive (since beginning 2010 we have to comply with lower SOx limit)
In order to keep ESP working reasonably well we kept limited CO promoter injection and low excess O2 in the regen. It looks like low NOx (I assume this means some NH3 slip from regenerator) increase ESP voltage.
Please note that the electrical part has been checked and there are no issues.
Do you think ESP voltage can be negatively influenced by increasing ESP temperature? Or is the ESP voltage decrease a consequence of the fouling (assuming catalyst deposits will build up also in the ESP if they build up on the FGC tubes) ?