20 Questions Identify Probable Causes for High FCC Catalyst Loss

8/13/2019 20 Questions Identify Probable Causes for High FCC Catalyst Loss

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REFINING DEVELOPMENTS SPECIALREPORT

20 questions: Identify probablecauses for high FCC catalyst lossHere is a list to troubleshoot your catalyst problems

P. K. NICCUM, KBR Technology, Houston, Texas

Fluid catalytic cracking unit (FCCU)performance and reliability are theprimary drivers of refinery economics.

Containment of the finely powdered cata-lyst within the circulating FCC unit inven-tory is a critical element of effective FCCoperation. Identifying the probable causesof high catalyst losses from a FCCU remainsone of the more important yet esoteric chal-lenges that can be faced by FCC operatorsand engineers. The answers to 20 key ques-

tions provide a basis to list the more likelycauses of high losses. Armed with this list, arefiner can develop cost-effective mitigationstrategies to relieve, if not solve, the problemonline or be prepared to confirm and correctthe situation during the next unit shutdown.This can prevent chasing unlikely solutions,while the real culprits escape detection.

Workhorse unit of the refinery.FCCU performance and reliability doimpact refinery economics. Containmentand minimizing losses of the finely pow-

dered catalyst within the circulating FCCunit inventory is critical. It is remarkablethat two-stage reactor and regeneratorcyclones, as depicted in Fig. 1, typicallycapture more than 99.997% of the cata-lyst dust entrained with the product andflue gas vapors. Any significant loss in theability to contain the catalyst will haveserious negative economic consequences,such as:

Catalyst contamination of slurry-oilproduct reducing its value in the market.

Severe erosion of slurry-circulation

pumps

Required cleaning of heavy oil tanksdue to catalyst buildup

Loss of compliance with permittedatmospheric particulate emissions

Premature failure of flue gas powerrecovery turbines

Loss of catalyst fluidity causes irregu-lar or unstable catalyst circulation leadingto lower FCC unit throughput and lessdesirable product yields

Several fold increase in fresh catalyst

makeup costs.After a ref inery notices an increase

in FCC catalyst loss rate, it may prema-turely conclude that the high loss ratemust be due to mechanical problemsthat can only be cured by a unit shut-down and repairs. This scenario can thendeepen when no obvious mechanicaldamage is found during the shutdownand it becomes apparent that the rootcause of the losses can only be diagnosedby gathering clues and studying unitoperations while the FCC unit is in ser-

vice. Indeed, the worst thing that can befound during the shutdown and inspec-tion could be finding nothing at all.

There are three categories of questionsthat can be asked when gathering clues todetermine the most likely cause of highFCC catalyst losses:

Questions with answers at your fin-gertips

Questions that should have readilyavailable answers

Questions whose answers requiredata or analysis beyond that considered

routine.

Cut-away view of FCC unit.FIG. 1

Originally appeared in:September 2010, pgs 29-38.Used with permission.


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REFINING DEVELOPMENTSSPECIALREPORT

HYDROCARBON PROCESSING SEPTEMBER 2010

These listed groupings can provide anorder for an investigation, starting withthe questions where answers are most eas-ily available, and working down the listtoward those requiring more time andcosts to answer.

Another complicating factor in FCCcatalyst loss investigations, like many trou-bleshooting exercises, is that some of thesupposed evidence may be corrupt or justplain wrong. It is up to the investigator tolook for what is being indicated by the pre-ponderance of the evidence, and not bedrawn into making premature conclusionsbased on limited data.

First things first: Q1Q7. If theincreased rate of catalyst loss is not severe,the first indication may be the report of

higher than expected fresh catalyst addi-tions needed to maintain the unit catalystinventory. The first order of business isto ascertain which side of the reactor-regenerator system, if not both sides, isresponsible for the increased catalyst loss,as listed in Table 1.

Q1: What is the relative rate of cata-lyst loss in the fractionator bottoms com-

pared to normal?Calculating the catalystloss rate through the reactor cyclones is nor-mally a straightforward multiplication ofthe slurry oil production rate times the con-centration of ash in the slurry oil product.

Q2: What is the relative stack opac-

ity or rate of fines catch compared tonormal?An increase in regenerator stackopacity generally indicates an increase instack catalyst emissions. It is noted thatparticles with diameters greater than a fewmicrons generally have an increasinglysmaller impact on opacity while those withdiameters in the range of 0.1 to 1.0 micronshave the larger impact on opacity.1,2Thepresence of third-stage separators, electro-static precipitators and flue gas scrubberscan obscure the impact of increased regen-erator catalyst losses on stack opacity.3

A concept referred to throughout thisarticle is What is normal? Unfortunately,in many cases, this normal data may bedifficult to obtain as the incentive to docu-ment problems often gets more prioritythan collecting data concerning what thingslook like when all is well.

It is also noteworthy if either the reactoror regenerator loss rate has decreased while

losses from the other vessel have increased.With a constant rate of fines input (freshcatalyst) and fines generation by attrition,anything that reduces the fines losses fromone vessel will increase the fines concentra-tion in the unit and result in a corresponding

increase in fines flowrate from the other ves-sel. For instance, commissioning a catalystslurry oil filter with recycle back to the riserwill increase the loss rate from a regenerator.

The equilibrium catalyst data sheetprovides a long-term accounting of manyimportant equilibrium catalyst propertiesthat are useful in diagnosing catalyst lossissues. Chief among these is the particlesize data.4

Q3: What is the relative amount ofequilibrium catalyst in the 040 micronrange?An equilibrium catalyst data sheet

provides a long-term accounting of manyimportant equilibrium catalyst propertiesthat are useful in diagnosing catalyst lossissues. Chief among these is the particlesize data.4The relative amount of fines inthe catalyst inventory is often indicatedby the percentage of the catalyst particleshaving a diameter less than 40 microns.This parameter provides an indication ofwhether or not the increased loss rate is dueto cyclone malfunction versus an increasein fines generation due to increased attri-tion or a higher loading of fines with the

fresh catalyst.Q4: What is the average equilibrium

catalyst APS compared to normal? Thechange in average particle size (APS) ofthe equilibrium catalyst generally movesopposite the fraction of fines in the cata-lyst. However, APS can also increase overtime due to decreasing equilibrium catalystwithdrawals that traps the largest particleswithin the circulating catalyst inventory.

Q5: How does the volumetric flowrateof reactor product vapors through thecyclones compare to normal? The volu-

metric rate of vapor flowing through thereactor cyclones can be estimated based onthe reactor operating temperature and pres-sure together with the hydrocarbon productrate, reactor and stripper steam rates, andan estimate of the hydrocarbon productmolecular weight. The rates and molecularweights of any hydrocarbon recycle streamsshould also be included in the calculations.

Q6: How does the volumetric flowrateof air or flue gas through the regeneratorcompare to normal? The regenerator airrate together with the regenerator operat-

ing temperature and pressure provide an

TABLE. 1. Questions with answers at your finertips

1. What is the relative rate of catalyst loss in the fractionator bottoms compared to normal?

2. What is the relative stack opacity or rate of fines catch compared to normal?3. What is the relative amount of equilibrium catalyst in the 040 micron range?

4. What is the average equilibrium catalyst APS compared to normal?

5. How does the volumetric flowrate of reactor product vapors through the cyclones compare to normal?

6. How does the volumetric flowrate of air or flue gas through the regenerator compare to normal?

7. How does the catalyst circulation rate compare to normal?

TABLE 2.Questions needing more investigation to resolve

8. What is the relative rate of catalyst loss from the regenerator compared to normal?

9. How does the fresh catalyst makeup rate compare to normal?

10. Are the losses steady or intermittent?

11. When did you last change the type of fresh FCC catalyst?12. When did the loss increase first occur?

13. How long did it take for the losses to increase from a normal rate?

TABLE 3.More difficult to resolve questions on FCC operations

14. What is the relative angularity of the equilibrium catalyst?

15. What is the relative angularity of lost catalyst?

16. What is the relative APS of the catalyst in the reactor carryover?

17. What is the shape of the differential particle size curve of the catalyst in the reactor carryover?

18. What is the relative APS of the catalysts in the regenerator carryover?

19. What is the shape of the differential particle size curve of the catalysts in the regenerator carryover?

20. How does the cyclone system pressure drop compare to normal?


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tor can be viewed under a microscope.The microscope can reveal whether thesample contains a high concentrationof small, jagged or broken pieces indi-cating an abnormally severe degree ofcatalyst attrition.

Q16: What is the relative APS of thecatalyst in the reactor carryover? Cata-lyst taken from the slurry oil can be sub-jected to the all important particle sizeanalysis. For a given rate of fines inputand fines generation within the unit,

material balance considerations dictatethat the APS of the lost catalyst mustincrease as the loss rate increases. Theimage from the microscope can corrobo-rate the particle size analysis by showingmore than an expected fraction of largerparticles and even very large particles thatwould never escape a properly function-ing cyclone system.

If the APS of the lost catalyst issmaller than normal, and if the loss rateis higher than normal, then that wouldindicate an increased degree of fines input

or increased catalyst attrition.

Moderately increasing APS wouldindicate some loss of cyclone efficiency;if the loss rate is higher than normal or areduction in fines input or attrition if the

loss rate is less than normal. Moderately increasing APS indicates

a reduction in fines input or attrition ifthe loss rate is less than normal.

A large increase in APS indicatesa major cyclone malfunction or seriousdamage.

Q17: What is the shape of the dif-ferential particle size curve of the cata-lyst in the reactor carryover? The particlesize analysis of a loss sample can also bereported as differential particle size dis-tribution, indicating the fraction of par-

ticles falling in narrow size ranges. This isa different presentation than a cumulativeparticle size distribution displaying theweigh percentage of particles having lessthan a given diameter.8The shape of thedifferential particle size distribution curvecan be insightful:

If the curve has only a single broadpeak centered about a higher than normalparticle size, as shown in Fig. 3, this couldindicate a partial loss of cyclone efficiencybut not complete bypassing of solids.

A bimodal curve having a peak near

that considered normal, as well as a sec-ondary peak at a lower than normal par-ticle size as shown in Fig. 4, may indicatea catalyst attrition problem.

Some bypassing of material aroundthe cyclones altogether would occur witha breached plenum chamber or a hole ina secondary cyclone outlet tube, as shownin Fig. 5. This would exhibit itself witha bimodal curve having peaks near thatconsidered normal, as well as a secondarypeak at a higher than normal particle size.

Q18: What is the relative APS of

the catalysts in the regenerator carry-

over? Collecting a representative sampleof catalyst lost from the regenerator is lessstraightforward than the collection of finesfrom slurry oil. Ideally, a dust sample can

be collected from the regenerator effluent,and the results can be analyzed as previ-ously discussed with respect to catalystseparated from slurry oil. If dust collectionequipment exists downstream of the regen-erator, such as a scrubber, ESP or TSS, thefines catch can also be analyzed and usedin the investigation.

Q19: What is the shape of the differ-ential particle size curve of the catalystsin the regenerator carryover? If a dustsample from the regenerator effluent canbe obtained, the results can be analyzed as

previously discussed with respect to cata-lyst separated from slurry oil.

Q20: How does the cyclone systempressure drop compare to normal? SomeFCC units are instrumented with differen-tial pressure measurements across the ves-sel disengaging space and the vapor outlet.This provides an indication of the pres-sure drop through the cyclone system andit will indicate whether there has been asignificant change in the catalyst or vaporloadings of the cyclones.

Once answers to many of the 20 ques-

tions are available, these answers can beanalyzed for fit with the characteristics ofthe problems described below to establishthe more likely causes of the catalyst lossproblem.

Possible FCC catalyst losses. Morecommon causes of high catalyst losses are:

Excessive attrition in a fluid bed.Catalyst attrition in a fluid bed is causedby catalyst particles colliding at highvelocity with other particles or solid sur-faces. The high particle velocities in a

fluid bed are chiefly the result of particle

Attrition

01

2

3

4

5

6

7

8

9

10

0 10 20 30 40 50 60 70 80 90 100

Particle size, microns

Percent,%

Bi-modal distribution indicating an attrition problem.FIG. 4

Hole or crack in outlettube or plenum

0

1

2

3

4

5

6

7

8

9

10

0 10 20 30 40 50 60 70 80 90 100

Particle size, microns

P

ercent,%

Bi-modal distribution indicating cyclone bypass.FIG. 5

What can be done to correcta plugged reactor cyclonedipleg online?

Lower the stripper bed level tounseal the diplegs.

Pressure bump the unit bychanging the vessel operatingpressure rapidly, say 4 psi in15 seconds.

What can be done to correctan attrition problem online?

Locate and correct any missing

orifices or valve openings.


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or flue gas system. Even a 10-mm hole canincrease the catalyst losses several fold. Intime, the passage of high velocity catalystthrough the hole will increase the holesize, and the catalyst losses will intensify.

Holes often start as cracks or tears in

the metal; in time, they grow due to theerosive effects of the catalyst flow. If thecatalyst loss problem is not yet severe, aunit inspection may have difficulty find-ing the cracks, as the cracks may tend toclose as the unit cools.

The impact of a hole in the outlettube or plenum of a reactor with risercyclones will be less than with an inertialriser termination device because there willbe little catalyst in the dilute phase thatcan be sucked into the hole.

Holes in a second-stage cyclone. Holes

in a secondary cyclone (or a single stagecyclone), including holes in the cyclonedipleg, will have serious consequences oncatalyst containment. The rate of perfor-mance deterioration will be controlled byhow quickly the hole enlarges due to ero-sion. Holes in the dipleg allow the vaporflow into and up the dipleg. This canrestrict the ability of catalyst to flow downthe dipleg. If the hole is in the cyclone body,then the incoming vapor jet can disrupt thedesired vapor profile in the cyclone, damag-ing the collection efficiency.

Holes in first-stage cyclone. Holesin primary cyclones are not as commondue to the lower velocities in primarycyclones. The catalyst loss impact froma hole in a primary cyclone will be muchless severe compared to a hole in a sec-ondary cyclone, because the secondarycyclone will catch almost all the catalystlost from the primary cyclone. In fact,it may be difficult to even notice theincreased catalyst loss associated with ahole in a primary cyclone.

Stuck open or missing flapper in

first-stage cyclone. Most first stagecyclones are submerged in a fluid bedand do not have or need check valvesbecause the catalyst traffic is sufficientlyhigh enough that gas does not force itselfup the dipleg. Sometimes check valves,as shown in Fig. 7, are included to limitlosses during startup when the diplegs arenot submerged. In these cases, a stuck-open flapper will be of little consequenceduring normal operations.

In some cases, due to the unit geom-etry or technical preference, the primary

cyclones can be designed to discharge

above the bed. In these cases, assumingthe cyclone is not a positive pressure risercyclone, a properly functioning valve isrequired. The consequences of a valve thatis stuck open would be a major loss ofcyclone efficiency, increasing the loading

to the secondary cyclones and increasingthe catalyst losses from the unit.

Stuck open or missing flapper in sec-ond-stage cyclone.A flapper that is stuckopen or missing may not affect the cycloneperformance if the dipleg is submerged suf-ficiently in a well-fluidized bed. If the bedfluidization is erratic, then the losses mayincrease due to unsteady catalyst flow downthe dipleg or due to gas bypassing up thedipleg. If the secondary cyclone dipleg isnot submerged into the fluid bed, a stuckopen or missing flapper turns the dipleg

into a vacuum tube sucking vapors into thecyclone; destroying the cyclone efficiency.A detached dipleg would have similar con-sequences.

Reactor cyclone overload.A reactorcyclone system can become overloadedif the catalyst or vapor traffic exceeds thedesign hydraulic capability of the cyclonesystem. The cyclone system pressure dropincreases with both catalyst and vaporloading. As the pressure drop increases,the catalyst in the dipleg must backup toa higher elevation, as shown in Fig. 8, to

provide enough static head to force thecatalyst out of the dipleg. When the cata-lyst height in the dipleg reaches the dip-leg top, the swirling vapors in the bottomof the cyclone will reentrain the catalystand drastically reduce cyclone collectionefficiency. This situation is referred toas cyclone flooding. Increasing reactorvapor traffic beyond the cyclone dipleghydraulic limit can occur by operating atan increased feedrate, higher conversion,and reduced operating pressure.

Catalyst loss can be intermittent

when cyclone dipleg hydraulic limitationsare the issue.

When operating near the cyclonedipleg hydraulic limit, even a smallincrease in catalyst circulation or vaporrate can result in increased catalyst losses.

Dipleg sizing is rarely a limitationduring normal operations, but if theregenerator temperature falls to verylow levels while maintaining riser outlettemperature, the catalyst circulation willincrease. At extreme conditions, the reac-tor cyclone dipleg can restrict the flow

of catalyst.

Regenerator cyclone overload. Aregenerator cyclone system can alsobecome overloaded when catalyst andvapor traffic exceed the hydraulic capabil-ity of the cyclone system:

Catalyst loss can be intermittent

when cyclone dipleg hydraulic limitationsare the issue. In some cases, the flue gasstack can appear to be puffing.

Increasing vapor traffic beyond thecyclone dipleg hydraulic limit can occurby operating at increased regenerator airrate, higher temperature and reducedoperating pressure.

Catalyst overload in regeneratorcyclones can occur for the same reasons

What can be done to correct acyclone design issue online?

Nothing, but try to rule out theother possible causes beforeshutting down.

Adjust operating conditionsto minimize losses until designmodifications are possible.

Catalyst bed level

Dipleg catalyst level

First-stage cyclone

Second-stage

cyclone

Cyclone hydraulic balance.FIG. 8

What can be done to correct

a stuck open or detachedcheck valve online?

It may be possible to reducecatalyst losses by raising the bedlevel to seal the dipleg.


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REFINING DEVELOPMENTS SPECIALREPORT


as vapor overload because the catalystentrainment rate to regenerator cyclones,as shown in Fig. 9, is a function of regen-erator superficial vapor velocity.12

Poor efficiencyCyclone design.

The suspicion of a poor efficiency cyclonedesign will typically be raised only afterthe installation of a new set of cyclones.Poor reactor cyclone efficiency due tocoke formation within the cyclone has alsobeen reported.9

Having said this, it would be a charac-teristic of a low efficiency cyclone design toexhibit a rather large average catalyst par-ticle size in the lost catalyst. Also, the dif-ferential particle size analysis curve wouldhave only a single peak as opposed to abi-modal peak associated with a damaged

cyclone. A low concentration of fines in thecirculating inventory would also be char-acteristic of low cyclone system efficiency.

Poor efficiencyRegeneratordesign. It would be a characteristic of alow-efficiency regenerator design to lacksufficient height or diameter to effec-tively disengage the catalyst rising fromthe fluid bed. Such a regenerator wouldexhibit a rather large average catalyst par-ticle size in the lost catalyst while the dif-ferential particle size analysis curve wouldhave only a single peak as opposed to a

bi-modal peak associated with a damagedcyclone. A low concentration of fines inthe inventory would also be characteristicof a low-efficiency regenerator design.The quality of the bed fluidization mayalso affect the catalyst entrainment rateand cyclone operability:

Defluidized sections of the bed mayinhibit flow from the submerged diplegs.

Spouting spent catalyst risers canthrow more catalyst up to the cyclones.

Specially designed baffles placedwithin the bed have been observed to

reduce catalyst entrainment.13

Fresh catalyst too soft. Soft FCC cat-alyst is one that inherently suffers from ahigher than average attrition rate whensubjected to the rigors of circulation inthe FCC unit. The softness of a catalyst is

the opposite of its hardness, a parameterdefined by the catalyst manufacturers asan Attrition Index.5This index is basedon a laboratory simulation of FCC cata-lyst attrition relying on the punishment ofa laboratory sample with a high-velocitygas jet at defined standard conditions.

Catalyst manufacturers offer varyingdegrees of catalyst hardness. Soft catalystis rarely an explanation for a catalyst lossproblem today.

Catalyst that is too soft will mani-fest itself as higher catalyst losses from

both the reactor and regenerator andhigher than normal equilibrium catalystfines content.

Fresh catalystHigh 040 microncontent.A fresh catalyst with a high 040micron content is one that is shipped witha larger than typical fraction of particleshaving diameters less than 40 microns.Catalyst with this character will lose ahigher percentage of their mass from theinventory shortly after being loaded intothe unit.

Fresh catalystHigh addition rate.

FCC unit catalyst losses have a definitecorrelation with the rate of fresh catalystadditions because increasing fresh cata-lyst addition rate increases fines input andbecause the fresh catalyst may have fragileedges that are lost more easily when thecatalyst is first introduced into the unit.

Higher catalyst losses are anexpected, normal result of increasing freshcatalyst addition rate.

Increased reactor fines retention.Whenever changes occur that limit theability of fines to escape from a reactor

system, the fines will find their way out

of the unit via a different avenues, whichare limited to the regenerator cyclones andincreased catalyst withdrawals. Examplesof changes that increase reactor catalystretention are:

Recycle of fines from the fractionatorbottoms back to the FCC reactor via con-

ventional slurry oil recycle system or aslurry-oil filter system.

Installation of new reactor cycloneshaving a higher design efficiency.

Increased regenerator fines retention.If the catalyst fines cannot get out throughthe regenerator, they will be forced to exitthe unit through the reactor. Examples ofchanges that increase regenerator catalystretention are:

Recycle of fines from an electrostaticprecipitator or third-stage separator backto the regenerator.

Installation of new regeneratorcyclones having a higher design efficiency

Feed contaminants and regeneratoroperating conditions that lead to stickycatalyst within the regenerator.

In the presence of high levels of flux-ing agents such as sodium, potassium, cal-cium, chlorides or vanadium that can beintroduced with contaminated feedstock,and especially at high temperatures, thecatalyst can become sticky. These flux-ing agents can form low melting eutecticswith the catalyst at temperatures as low as

930F to 1,200F.5

What can be done to correcta dipleg hydraulic problemonline?

Reduce dipleg submergence

by lowering the catalyst bed level Lower vapor and/or catalystcirculation rates.

Increase operating pressure.

What can be done to correct catalyst-induced

loss problem online?

Sometimes refiners purposely add fresh catalyst with highfines content, low density, lower Attrition Index, or just anincrease in fresh catalyst makeup rate to improve the fluidity

of the catalyst inventory. With that in mind, consider: Ordering fresh catalyst with lower agreed limits on 040

micron particle content. Changing to a catalyst with higher particle density or one

with increased attrition resistance. Reducing the fresh catalyst makeup rate.

Ve= Effective superficial vapor velocity, fps

p= Particle density, lb/ft

3

g= Gas density, lb/ft

3

e = Entrainment, lb cat/ft3vapor

0.05

0.04

0.03

0.02Ve

/p

0.01

1 10 20 3098765e/g

2 43

Catalyst entrainment correlation.FIG. 9


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There will be times that even withthoughtful consideration of the answersto the 20 questions, and even after unitshutdowns and inspections, the cause ofhigh FCC catalyst losses will remain elu-sive. However, FCC product economics,

reliability and environmental concernsmay compel refiners to resort to extraor-dinary tactics for finding the source of thehigh losses.

Extraordinary measures.A numberof more costly and time-consuming optionsin searching for the root cause of high cata-lyst losses include:

Cold-flow modeling Radioactive tracers and gamma ray

scans Cyclone pressure testing

Computational fluid dynamic simula-tions.

The road to the conclusion of an investi-gation into the cause of high catalyst lossesmay prove to be long and arduous. How-ever, if the investigation stays the course,the road will usually lead to success. HP

LITERATURE CITED 1 Ensor D. S., and M. J. Pilat, Calculation of

Smoke Plume Opacity from Particulate Air

Pollutant Properties, 63rd Annual Meeting of

the Air Pollution Control Association, St. Louis,

Missouri, June 1418, 1970. 2McClung, R. G., Effect of FCC Catalyst Fines

Particle Distribution on Stack Opacity, The

Catalyst Report, Engelhard Corp., 1994.3Niccum, P. K., E. Gbordzoe and S. Lang, FCC

Emission Options, NPRA Annual Meeting,

March 2002, San Antonio. 4Montgomery, J. A., More about Davisons

Equilibrium Fluid Cracking Catalyst Analysis

Program, Davison Catalagram, No. 63, Davison

Chemical Division, W. R. Grace & Co., 1981. 5 Linden, D. H., Catalyst Deposition in FCC

Power Recovery Systems, Katalistiks 7th Annual

Fluid Cat Cracking Symposium, Venice, Italy,

May 1213, 1986. 6 Weeks, S. A. and P. Dumbill, Method speeds

FCC catalyst attrition resistance determinations,

Oil & Gas Journal, April 16, 1990, pp. 3840. 7Zhou, F., C. Liu, J. Liu and S. Shu, Use micro-

graphs to diagnose FCC operations, Hydrocarbon

Processing, March 2006. 8 Fletcher, R., Stepwise method determines source

of FCC catalyst losses, OGJ, Aug. 28, 1995.

9McPherson, L. J., Causes of FCC Reactor Coke

Deposits Identified, OGJ, Sept. 10, 1984.10Session II.A-Fluid Catalytic Cracking, Mechanical

Question 6, NPRA Q&A Session on Refining and

Petrochemical Technology, 1994.11Zenz, F. A. and D. F. Othmer, Fluidization and

Fluid-Particle Systems, Reinhold Publishing Co.,

New York, 1960.12Giuricich, N. L. and B. Kalen, Dominant Criteria

in FCC Cyclone Design, Katalistiks 3rd Annual

Fluid Cat Cracking Symposium, May 2627, 1982,

Marriot Hotel, Amsterdam, The Netherlands.13Miller, R. B., Y-Lin Yang, T. E. Johnson,

S. J. McCarthy and K. W. Schatz, REGENMAX

Technology: Staged Combustion in a Single

Regenerator, NPRA Annul Meeting, March

1999, San Antonio.

Phillip Niccumjoined KBRs fluid catalytic cracking

(FCC) team in 1989. He has held various FCC-relatedpositions at KBR including process manager, chief tech-

nology engineer of FCC, and is currently director of FCC

Technology for KBRs Technology business unit. Following

graduation from California State Polytechnic University

with a degree in chemical engineering in 1980, he began

his career in the Central Engineering Department at Tex-

aco USA headquarters, where he provided design and

technical assistance to Texaco FCC units worldwide.

Article copyright 2010 by Gulf Publishing Company. All rights reserved. Printed in U.S.A.

Not to be distributed in electronic or printed form, or posted on a website, without express written permission of copyright holder.

www.kbr.com/fcc

20 Questions Identify Probable Causes for High FCC Catalyst Loss

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