low nox fcc promoter optimization at citgo _catalagram 108 excerpt_
TRANSCRIPT
Catalagram®
ARefining Technologies Publication
Issue No. 108 / 2010 / www.grace.com
Celebrating 100 years of operationsat our Curtis Bay Works
®
Dear Refiners,
These are difficult times, highly unpredictable and fullof uncertainties. The last two years, for example, havebeen unlike anything I have ever experienced sincejoining Grace Davison’s RT North American sales forcein 1986. I believe that as 2010 comes to an end and2011 begins, we must, more than ever, critically exam-ine our actions to become better prepared for this com-ing year of uncertainties.
Everyone is conscious of price. Every day the papersand journals are replete with articles and editorials citing the recent governmental rulings and interpreta-tions as they apply to our various businesses.
In addition to all the imposed controls, we at Grace Davison have observed our raw material escalate inthe last two years at a higher rate than we have ever before seen. However, our fluid cracking catalystsremain one of the biggest bargains available to the refiner today. Grace Davison, as the industry leader,has been instrumental in advancing the catalytic side of FCC technology, while at the same time, routinelypassing along to the refiner the fruits of our cost-savings programs. Our AlcyonTM catalyst is a perfectexample of just such a saving.
Prices that are too low cannot produce the return on investment necessary to maintain efficient plants,provide the capital to meet pollution standards, conduct an aggressive research effort, continue the neces-sary and much appreciated services and, most importantly, guarantee the continued supply of consistent,high quality, premium catalysts the refining industry has come to expect from Grace Davison.
Healthy suppliers are a requisite for a healthy industry.
Whatever your FCC catalyst and additives requirements, you can feel confident that we at Grace Davisonwill continue delivering the quality and service we have been known for in our 68 years of serving theworld’s refineries.
Sincerely,
Emery J. UdvariTechnical Sales Leader, North AmericaGrace Davison Refining Technologies
A MESSAGE FROM THE GUEST EDITOR...
GRACE DAVISON CATALAGRAM® 1
Guest Editor Emery Udvari
IN THIS ISSUE
Catalagram 108ISSUE No. 108 / 2010
Managing Editor:Joanne Deady
Technical Editor:Rosann Schiller
Contributors:Colin Baillie
Ann Benoit
Wu-Cheng Cheng
Denise Farmer
Eric Griesinger
David Hunt
Renaud Kieffer
Stuart Kipnis
Maria Luisa Sargenti
Rosann Schiller
Yuying Shu
Emery Udvari
Kristen Wagner
Dieter Wallenstein
Rick Wormsbecher
Guest Contributor:Kent Turner, CITGO
Petroleum Corporation
Please address your comments to:[email protected]
Grace Davison RefiningTechnologies7500 Grace DriveColumbia, MD 21044410.531.4000
www.e-catalysts.comwww.grace.com
© 2010 W. R. Grace & Co.-Conn.
Alcyon™: New Catalyst Design for MaximumActivity and ConversionBy Rosann Schiller, Ann Benoit and Yuying Shu
Reducing Sulfur Oxide Emissions from the FCCUnitBy Renaud Kieffer, Maria Luisa Sargenti and Colin BaillieGrace Davison Refining Technologies Europe
OlefinsUltra® HZ Technology ImprovesPropylene YieldsBy Kristen Wagner and Denise Farmer
The Role of the Rare Earth Elements in FluidCatalytic CrackingBy Rick Wormsbecher, Wu-Cheng Cheng, and DieterWallenstein
Answers to the 2010 NPRA Q&A FCC QuestionsBy Rosann Schiller, David Hunt and Stuart Kipnis
Low NOx FCC Promoter Optimization at CITGOPetroleum Corporation’s Lake Charles RefineryBy Kent Turner, CITGO Petroleum Corp.; David Hunt and EricGriesinger, Grace Davison
From the Editor:
This issue reflects the refining industry's current concern with theprice and availabilitly of rare earth. This crisis is addressed in ourGuest Editorial on the opposite page, as well as in a technical arti-cle. Grace Davison remains committed to providing refiners withtechnology for tailored solutions, a broad product portfolio, strong,market-focused R&D, flexible manufacturing, and the industry-lead-ing tech service you have come to expect from us.
On another note, Yuying Shu, co-author of the AlcyonTM catalystarticle, has been honored by the Daily Record as one of 25Maryland "Innovator of the Year" recipients. Yuying is recognizedalong with the rest of the AlcyonTM catalyst Team: Jeff DelMartin,Ruizhong Hu, Brent Machado, Rosann Schiller, Wilson Suarez andRick Wormsbecher.
Finally, the front cover of this issue features our Curtis Bay plant,which celebrated its 100th anniversary of operation in September2010. While our FCC plant is far newer than that, we join our fel-low employees in marking this milestone.
Sincerely,Joanne DeadyVice-President, Global MarketingGrace Davison Refining Technologies
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GRACE DAVISON CATALAGRAM® 33
Low NOx Promoter Optimization atCITGO Petroleum Corporation’sLake Charles Refinery
Kent Turner
FCC Process Engineer
CITGO Petroleum
Corporation.
Lake Charles, LA
Eric Griesinger
Environmental Additives
Marketing Manager
Grace Davison
Refining Technologies
Columbia, MD
Summary
CITGO has successfullyapplied CP® P, GraceDavison’s third generationLow NOx FCC combustionpromoter, at their LakeCharles refinery. CP® P pro-moter replaced GraceDavison’s first generation lowNOx promoter, XNOX®, andGrace’s second generation
low NOx promoter XNOX® 2,and built on the successfulapplication of these products.
CP® P promoter allowedCITGO to reduce regeneratorexcess O2 levels by ~0.3%and improve CO emissions atsimilar NOx levels. Operatingwith lower excess O2 providedadditional operating flexibilityin terms of feed rate and con-
David Hunt
Technical Manager
Grace Davison
Refining Technologies
Houston, TX
version. CP® P promotersteady state additions were75% lower than the baseXNOX®promoter, resulting insignificant cost savings aswell as improved product per-formance.
Table VI summarizes theresults of the evaluation.
34 ISSUE No. 108 / 2010
CP® P promoter has beensuccessfully used in over tenFCC units to date, in additionto the FCCU’s at CITGO’sLake Charles refinery.Commercial experience con-firms that CP® P promoter hasequal activity as a mediumactivity platinum COCombustion additive likeGrace Davison’s CP® 5 pro-moter. CP® P promoter is cop-per free.
Unlike earlier generations oflow NOx promoters, CP® Ppromoter does not requirestrict adherence to mainte-nance dosing. CP® P promot-er can be used withimmediate reduction in FCCregenerator afterburn and COsimilar to traditional platinum-based promoters, but withoutlingering NOx emissions.Daily dosing of CP® P promot-er, however, is recommendedto achieve consistent CO,afterburn and NOx Control.1
Background
CITGO Petroleum operates a425,000 bpd sour crude refin-ery in Lake Charles, LA withthree similar FCC units (A-Cat, B-Cat and C-Cat). Allthree FCCU’s are KelloggModel II designs constructedin 1944 and have been
revamped to include verticalrisers, modern FCC feed noz-zle and riser termination tech-nologies. The FCC feedstockto each FCCU consists ofsour vacuum and coker gasoils. Each FCCU operates infull combustion mode.
On October 6, 2004, CITGOagreed to a set of environ-mental operation parameterswith the EnvironmentalProtection Agency (EPA).CITGO installed wet gasscrubbers on each FCCU in2005 and 2006 to meet SOxemissions limits of 25 ppm,365 day and 50 ppm, sevenday rolling average limits(25ppm/50ppm). CO limits of100ppm/500ppm and a partic-ulate limit of 1 lb/1000-lb cokewere also established foreach FCCU as part of theagreement.
CITGO’s agreement with theEPA also required that lowNOx promoter and NOxreduction additives be used toestablish long-term NOx lim-its. CITGO stopped Pt formu-lated CO promoter additionsand evaluated several EPAapproved low NOx promotersand NOx reduction additivesin a series of short-term trials.
Grace Davison’s low NOxpromoter, XNOX®, and NOxreduction additive, DENOX®,were identified as the bestperforming products duringthose short-term trials.CITGO then conducted anoptimization evaluation withboth products, followed by ademonstration period with theoptimized addition rates.
During the demonstrationperiod, it was evident thatCITGO was successfullymeeting EPA target NOxemission levels with the appli-cation of XNOX®, DENOX®,and tight control of flue gasexcess O2. As a result,CITGO elected to stop thedemonstration period andaccept EPA standard NOxlimits of 20 ppm/40ppm.
Low NOx PromoterOptimization
The use of combustion pro-moter is critical to meet FCCemission limits at CITGO’sLake Charles Refinery. WithNOx limits established, GraceDavison recommended thatCITGO evaluate new, moreactive, non-platinum promoteradditives available fromGrace Davison.
The FCCU’s at CITGO oper-ate within a narrow rangebetween its NOx and COemissions limits. CITGO typi-cally minimizes flue gasexcess O2 to inhibit NOx for-mation. However, as O2 isreduced, CO eventuallybegins to increase. CITGO iscareful to add just enoughcombustion promoter to meetCO limits, but not excessiveamounts that would risk ele-vated NOx formation. CITGO
Low NOxPromoterXNOX®XNOX® 2CP® P
AdditiveAdditions
Base
50% Base
25% Base
NOx CO (1) O2 Afterburn
Base
~
~
Base
Lower
Lower
Base
Lower
Lower
Base
~
~
Table VILow NOx Promoter Evaluation Data Summary
(1) CITGO could have elected to operate at similar CO levels and lower NOx levels byre-optimization of the promoter additions and excess O2 levels.
GRACE DAVISON CATALAGRAM® 35
has found that twice dailyadditions of CO combustionpromoter are optimal to meetCO, NOx, and regenerationafterburn objectives.
After the conclusion of thetest period, CITGO elected tofurther optimize promoteradditions by testing a secondgeneration low NOx CO pro-moter from Grace Davison,XNOX® 2, followed by GraceDavison’s newest low NOxCO promoter CP® P. CITGOand Grace Davison estab-lished a test plan whichincluded product additionrates, data monitoring, andmilestones.
XNOX®2 CombustionPromoter
XNOX® 2 promoter is moreactive than XNOX® promoterand CITGO immediatelyreduced promoter additionsby half, once they beganusing XNOX® 2promoter.
CITGO noted a fundamentalshift in the relationshipbetween CO and O2 in theFCC flue gas with XNOX® 2promoter. Figure 22 showsthat XNOX® 2 promoter shift-ed the CO vs. O2 curve to amore favorable position. WithXNOX® 2promoter, CITGOwas able to reduce excess O2for the same level of CO. Byoperating at lower excess O2,CITGO was afforded addition-al operating flexibility in termsof rate and conversion withinNOx emission limits and airblower constraints.
Flue gas NOx levels andAfterburn were maintainedwith XNOX® 2 promoter at halfof the promoter additions asshown in Figures 23 and 24.
0.0
CO
,pp
mv
0.5 1.0 1.5 2.0 2.5 3.0
600
400
500
200
300
100
0
XNOX® 2 Promoter CP® P Promoter
O2, vol.%
3.5
Figure 22CO vs. O2 - XNOX
® and XNOX®2 Promoters
WG
SS
tack
CE
MS
NO
x,p
pm
XNOX® Promoter XNOX® 2 Promoter CP® P Promoter
Figure 23NOx Promoters
Reg
ener
ato
rA
fter
bu
rn,˚
F
XNOX® Promoter XNOX® 2 Promoter CP® P Promoter
Figure 24Regenerator Afterburn
36 ISSUE No. 108 / 2010
Data shown in Figures 22, 23and 24 represents data fromone of the three FCC units atthe CITGO Lake CharlesFacility. Similar conclusionswere also made in CITGO’sother two FCCU’s.
CP® P CombustionPromoter
CITGO evaluated CP® P pro-moter after a successful appli-cation of XNOX® 2promoter.CP® P promoter was moreactive than XNOX® 2 promot-er and CITGO reduced addi-tions of CP® P promoter by75% relative to the baseXNOX® promoter additions.
CP® P promoter was able tomaintain the favorable rela-tionship of CO versus O2 thatXNOX® 2 promoter providedas shown in Figure 25. As aresult, CITGO continued tominimize excess O2 without aCO penalty.
NOx production and afterburncontinued to be controlledwith CP® P promoter asshown in Figures 23 and 24.
Acknowledgements
The authors would like tothank CITGO Petroleum man-agement for permission topublish this work.
References
1. E.Griesinger, M. Ziebarth, Udayshankar
Singh., “Development of Next Generation
Low NOx Combustion Promoters Based on
New Mechanistic Insights”, Catalagram®, 107
(2010).
0.0
CO
,pp
mv
0.5 1.0 1.5 2.0 2.5 3.0
200
160
180
120
140
80
100
40
60
0
20
XNOX® 2 Promoter CP® P Promoter
O2, vol.%
Figure 25CO vs. O2 - XNOX
® 2 and CP®P Promoters
[email protected] www.e-catalysts.com
Catalagram®, Grace®, Grace Davison®, GENESIS®, MIDAS®, IMPACT®, CP® P, XNOX®, OlefinsUltra® are registered trademarksin the United States and/or other countries, of W. R. Grace & Co.-Conn.
ENCORE™ and Alcyon™ are trademarks of W. R. Grace & Co.-Conn.
Grace Davison® is a business unit of W. R. Grace & Co.-Conn.
This trademark list has been compiled using available published information as of the publication date of this brochure and may notaccurately reflect current trademark ownership.
© 2010 W. R. Grace & Co.-Conn.
The information presented herein is derived from our testing and experience. It is offered, free of charge, for your consideration,investigation andverification. Since operating conditions vary significantly, and since they are not under our control, we disclaim any and all warranties on the resultswhich might be obtained from the use of our products. You should make no assumption that all safety or environmental protection measures areindicated or that other measures may not be required.