I.FLUID CATALYTIC CRACKING: www.wissenschaftler-avh.in
B.CATALYST/ADDITIVES:
Q-42
I would like to know the optimum FCC catalyst activity normally considered on operating FCCU's nowadays? Is there a target for the fresh catalyst MAT activity? Can we say 75 wt% is a low activity for fresh catalyst and we should request higher activity from Vendor? Or we can accept such value but we consider high catalyst addition rate in order to maintain Ecat activity at acceptable and optimum range (67-70 wt%)? The reason I raised these questions is that I noticed wide fluctuation on E-cat activity on our FCCU which indicated to me that there is something wrong either with the the newly utilized catalyst or the addition rate is not enough for maintaining target activity
A-42
If your fresh catalyst activity is really 75 wt%, then this would be very low. I suspect, however, that this number represents the activity of the fresh catalyst after steam deactivation, and depending on the steaming conditions, this may be a very reasonable number. An equilibrium activity of 67-70 wt% would be optimum for many FCC's. If however, you are trying to operate at extremely high conversions, you might want to target a value of 72 wt%.
There are many possible causes for our high make-up rates. These could include feed contaminants, fresh catalyst quality, or operating conditions in the regenerator. Can you relate the variations in catalyst activity to any changes in unit operation or feed stock? You might also want to check the flow of various steam injections into the unit. Torch oil nozzle purges and atomization steam rates are a frequent culprit in catalyst deactivation problems.
It may also be possible that the variations you see are due to testing inaccuracy. Typically, the activity test is accurate to about plus or minus 2 wt%, but if there are testing problems, this variation could be higher. You might want to consider sending some blind duplicates for testing and see how much variation you get between these samples.
It would also be a good idea to verify that your catalyst sampling procedure gives a representative sample of the equilibrium catalyst.
B.CATALYST/ADDITIVES:
Q-42
I would like to know the optimum FCC catalyst activity normally considered on operating FCCU's nowadays? Is there a target for the fresh catalyst MAT activity? Can we say 75 wt% is a low activity for fresh catalyst and we should request higher activity from Vendor? Or we can accept such value but we consider high catalyst addition rate in order to maintain Ecat activity at acceptable and optimum range (67-70 wt%)? The reason I raised these questions is that I noticed wide fluctuation on E-cat activity on our FCCU which indicated to me that there is something wrong either with the the newly utilized catalyst or the addition rate is not enough for maintaining target activity
A-42
If your fresh catalyst activity is really 75 wt%, then this would be very low. I suspect, however, that this number represents the activity of the fresh catalyst after steam deactivation, and depending on the steaming conditions, this may be a very reasonable number. An equilibrium activity of 67-70 wt% would be optimum for many FCC's. If however, you are trying to operate at extremely high conversions, you might want to target a value of 72 wt%.
There are many possible causes for our high make-up rates. These could include feed contaminants, fresh catalyst quality, or operating conditions in the regenerator. Can you relate the variations in catalyst activity to any changes in unit operation or feed stock? You might also want to check the flow of various steam injections into the unit. Torch oil nozzle purges and atomization steam rates are a frequent culprit in catalyst deactivation problems.
It may also be possible that the variations you see are due to testing inaccuracy. Typically, the activity test is accurate to about plus or minus 2 wt%, but if there are testing problems, this variation could be higher. You might want to consider sending some blind duplicates for testing and see how much variation you get between these samples.
It would also be a good idea to verify that your catalyst sampling procedure gives a representative sample of the equilibrium catalyst.
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