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CatalagramA Refining Technologies Publication
Issue No. 109 / 2011 / www.grace.com
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Investing in Innovation
It's a fact that many companies slash research and development during difficult
economic times. But, in keeping with our value of putting our customers first,
Grace Davison has held R&D expenditures and increased capital budgets to
support investment in new technologies.
So why invest in innovation? One of our core principles emphasizes building
strong customer relationships by meeting current needs while anticipating future
challenges. And investment in research pays for Grace Davison and our refin-
ing customers on a daily basis with optimized operations.
What does investment in innovation look like?
Anticipating future challenges-Zeolite performance underlies FCC technology. Accessibility and activity are key.
That's why we're excited to join with Rive Technology on the revolutionary "Molecular Highway" technology to deliver
FCC catalysts that extend the possibility of catalyst performance in ways we can only anticipate. You are invited to
get a first glimpse at this process inside. We look forward to working with you and Rive to develop the catalysts that
not only meet, but exceed your future challenges. Let us know how you think this innovation will help you.
Meeting current customer needs-We don't need to restate the current rare-earth situation. You already know all
about it, but what you don't know is that Grace Davison's Research scientists never lost focus on the importance of
low and zero rare-earth catalysts and additives. We continue to examine the role of rare-earth in catalyst perform-
ance and how to not only use less rare earth but to maximize its efficiency and minimize, or even eliminate, its use.
Our world-class Technical Service engineers support you so that you realize the maximum value from our commit-
ment to the future of refining. Weve included an update on equilibrium catalyst trends from the last decade to help
you benchmark your operation and catalyst performance. And Grace Davison and ART Tech Service engineers
have collaborated on an article inside detailing the optimization of FCC feed hydrotreater and FCC unit performance
to drive the combined operation for maximum product value.
Grace Davison restates our pledge to invest in innovation to make you, our customers, successful.
We welcome your comments.
Sincerely,
Rosann K. Schiller
Senior Marketing Manager
Grace Davison Refining Technologies
A MESSAGE FROM THE EDITOR...
GRACE DAVISON CATALAGRAM 1
Rosann K. SchillerEditor
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IN THIS ISSUE
Catalagram 109ISSUE No. 109 / 2011
Managing Editor:
Joanne Deady
Technical Editor:
Rosann Schiller
Contributors:
Colin Baillie
Eric Griesinger
Sudhakar Jale
Ruizhong Hu
David Hunt
Dennis Kowalczyk
Charles Olsen
Rosann Schiller
Uday Singh
Kelly Stafford
Olivia Topete
Kristen WagnerBrian Watkins
Guest Contributors:
Javier Garcia-Martinez
Allen Hansen
Barry Speronello
Please address your comments to:betsy.mettee@grace.com
Grace Davison RefiningTechnologies7500 Grace Drive
Columbia, MD 21044410.531.4000
www.e-catalysts.comwww.grace.com
2011 W. R. Grace & Co.-Conn.
Catalagram
A Refining Technologies Publication
Issue No. 109 / 2011 / www.grace.com
Jointly Developed FCC Catalysts with NovelMesoporous Zeolite Deliver Higher Yields and
Economic Value to RefinersBy Barry Speronello, Javier Garcia-Martinez, Allen Hansen,Rive Technology and Ruizhong Hu, Grace Davison Refining
Technologies
The Development of Rare-Earth FreeFCC CatalystsBy Colin Baillie and Rosann K. Schiller, Grace DavisonRefining Technologies
A New Generation of Super DESOX AdditiveBy Eric Griesinger, Marketing Manager, Grace DavisonRefining Technologies
ResidUltraTM: Low RE Catalyst Technology for Resid
Processing ApplicationsBy Sudhakar Jale and Ruizhong Hu, Grace Davison RefiningTechnologies
Worldwide FCC Equilibrium Catalyst Trends
By Olivia A. Topete, Grace Davison Refining Technologies
GDNOXTM 1 Additive - Grace Davisons Next
Generation NOx Reduction Additive
By Eric Griesinger, Grace Davison Refining Technologies
Improving FCC Economics with Light Olefins
AdditivesBy Kristen Wagner, Grace Davison Refining Technologies
Higher Profits from Higher SulfurBy Kristen Wagner, Grace Davison Refining Technologies
Grace Davisons EZTM Loader Additive Injection
SystemBy Kelly Stafford, Grace Davison Refining Technologies
Balancing the Need for Low Sulfur FCC Productsand Increasing FCC LCO Yields by Applying
Advanced Technology for Cat Feed HydrotreatingBy Brian Watkins and Charles Olsen, Advanced RefiningTechnologies and David Hunt, Grace Davison RefiningTechnologies
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GRACE DAVISON CATALAGRAM 3
Jointly Developed FCC Catalystswith Novel Mesoporous ZeoliteDeliver Higher Yields and Economic
Value to Refiners
Background
Rive Technology and Grace Davison are commercializing advanced fluid catalytic cracking (FCC) catalysttechnology that dramatically increases the yield of transportation fuels per barrel of crude oil. Rives
Molecular Highway technology makes traditional zeolite catalysts more capable of cracking large hydro-carbon molecules, and allows valuable primary cracked products, like gasoline and diesel molecules, tomore readily escape the catalyst before they are overcracked to less valuable light gases and coke. Thisnew catalyst is a drop-in replacement for current catalysts and will enable refiners to increase throughputand profitability without capital investment. In this paper we explain Rive zeolite technology, describe itsincorporation into a Grace proprietary catalyst matrix formulation, and discuss preparations for a first refin-ery trial later this spring.
Barry Speronello, Ph.D., Research Fellow, Rive Technology, Inc.
Javier Garcia-Martinez, Ph.D., Co-Founder, Rive Technology, Inc.
Allen Hansen, Process Modeling Engineer, Rive Technology, Inc.
Ruizhong Hu, Ph.D., Manager of Research and Tech Support,Grace Davison Refining Technologies
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4 ISSUE No. 109 / 2011
Rives Molecular Highway Technology
Since the introduction of zeolite-based catalyticcracking in the 1960s, zeolite Y has been theactive ingredient of choice. Its relatively stable atthe high temperatures within the FCC unit (up toabout 1400F) and very efficient at catalyzing thecracking of smaller FCC feed molecules that canenter through its micropores, (with pore mouths ofabout 0.7 nm.). However, as illustrated in Figure1, many feed molecules are too large to enter Yzeolite micropores and must first pre-crack lessselectively either thermally or outside of the zeolitebefore entering the zeolite crystals. Similarly, larg-er gasoline and LCO product molecules are a tightfit within zeolite pores and can take a relativelylong time to leave the zeolite crystal. During thatrelatively long stay within the micropores, suchvaluable products can be recracked (overcracked)
to less valuable gases and coke.
Rive zeolite technology was invented at MIT inthe early 2000s by Garcia-Martinez and Ying. Itimproves on zeolite Y by creating a network ofintermediate sized (2 - 6 nm.) mesoporous molec-ular highways throughout the crystals of zeolite Y.These molecular highways admit and pre-crack
Gasoline & diesel molecules have
difficulty exiting zeolite micropores and
are prone to overcracking to coke and
gases before escapingLarge feed molecules
cant enter micropores
Figure 1Small Pores in Conventional Y Zeolite Are Not Optimal for Cracking
even the largest feed molecules, while also chan-neling product gasoline and diesel molecules safe-ly out of the zeolite.
Mesopores in Rive zeolite can be clearly seen intransmission electron microscope (TEM) images,such as those shown in Figure 2. Figure 2a is aTEM image of a conventional Y zeolite crystalshowing its rows of lattice reflection lines resultingfrom the regular atomic structure within the crystal(a few are highlighted in red for clarity). Figure 2bof a mesoporous Rivezeolite crystal similarlyshows the crystal lattice lines, but in addition onecan see the larger, lighter colored spots corre-sponding to the mesopores in the Rive zeolite (afew of which are circled in red).
The size and volume of mesopores created in Yzeolite can be controlled over a fairly wide range
with Rives Molecular Highway technology.Figure 3, below, shows a pore size distribution typ-ical of that used for catalytic cracking. The graphcompares the cumulative pore volumes of bothRive Y zeolite and conventional Y zeolite as afunction of pore diameter, and it shows that bothtypes contain a large volume of micropores at
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GRACE DAVISON CATALAGRAM 7
API
CCR
Sulfur
IBP
50%
95%
Kwatson
Ca
19.60
0.29%
2.39%
577F
831F
1000F
11.63
25.75
Table ICPERI Feedstock Properties
shows ACE testing results for a preferred formula-tion after steaming for 4 hrs at 1450F and 100%steam.
Table I lists the feed properties. While the feedused for this study had a relatively low CCR and90% boiling point, its low API gravity and high Cashow that it is relatively aromatic and difficult to
crack.
Figure 5a is a plot of gasoline yield vs. conversioncomparing a catalyst containing Rive zeolite (inRed) to a catalyst containing conventional zeolite.The zeolites were processed to have the samesteamed crystal unit cell size and the catalystshad the same zeolite contents and matrix formula-tions.
Figure 5a shows that the benefits of Rive zeo-lite mesoporosity translate well from pure zeolite
powders to catalysts. In this case the uplift wasabout 3 percentage points (about 6% relative)compared to the catalyst made using convention-al zeolite.
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8 ISSUE No. 109 / 2011
55
50
45
40
35
3050 55 60 7065 75 80 85
Conversion, wt. %
12
8
6
4
2
050 55 60 7065 75 80 85
Conversion, wt. %
10
22
18
16
14
12
1050 55 60 7065 75 80 85
Conversion, wt. %
20
Conventional Zeolite
RiveTM Zeolite
Figure 5a
Figure 5b Figure 5c
Coke,wt.%
LCO,wt.%
Gasoline,wt.%
Figure 5Comparisons of Gasoline, Coke, and LCO Yields of Silica Sol Matrix FCC CatalystsContaining RiveTM and Conventional Zeolites When Cracking Aromatic Gasoil in anACE Unit
Similarly, Figure 5b compares the coke yields ofthe two catalysts and shows that that the catalysthaving Rive zeolite made about 1 percentagepoint (15% relative) less coke than the catalyst
containing conventional zeolite.
LCO yields (Figure 5c) were similar for the twocatalysts, though, so the advantage in bottomscracking seen with the pure powders was dimin-
ished when mesoporous zeolite was formulatedinto a silica sol matrix and used to crack this rela-tively challenging feedstock.
The first commercial catalyst formulations con-taining Rive mesoporous zeolite were devel-oped based on ACE testing using paraffinicvacuum gasoil. Controls for these tests were alu-mina-matrix commercial catalysts A (moderate
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GRACE DAVISON CATALAGRAM 9
50 55 60 7065 75
53
69
77
85
45
61
6
5
4
3
2
1
0
28
25
22
19
16
13
10
55
51
47
43
39
35
80 85 50 55 60 7065 75 80 85
50 55 60 7065 75 80 850 3 6 129
Cat/Oil Ratio
Conversion, wt. %
Conversion, wt. %
Conversion, wt. %
Ecat A Steamed Cat A
Conversion,wt.%
Coke,wt.%
LCO,wt.%
Ga
soline,wt.%
Figure 6Selectivities of Lab Deactivated and Equilibrium FCC Catalysts Were Identical
rare earth) and B (high rare earth). Both equilibri-um catalyst and lab deactivated fresh catalystswere used in the comparisons.
Figure 6 contains graphs of conversion vs. cat/oilratio, and selectivities vs. conversion for the equi-librium and lab deactivated versions of commer-cial catalyst A. It shows that the deactivation
conditions used for this test (8 hrs/1450F/100%steam) were somewhat less severe than thatexperienced in the FCCU, but the selectivitymatches were excellent.
Figure 7, below, is a comparison of a steamedGRX catalyst formulation containing a moderaterare earth mesoporous Rive zeolite with labsteamed commercial catalyst A. The two cata-lysts were substantially equal in activity, yieldingsimilar conversions at equal cat/oil ratios. Therewas also little difference in gasoline selectivitybetween the two. There was, however, a signifi-
cant benefit in bottoms upgrading and coke selec-tivity for the GRX catalyst containingmesoporous Rive zeolite, and those benefitsare particularly evident in the graph of bottoms
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10 ISSUE No. 109 / 2011
53
69
77
85
45
61
0 3 6 129
Cat/Oil Ratio
Catalyst A GRX Catalyst
55
51
47
43
39
35
50 55 60 7065 75 80 85
Conversion, wt. %
Conversion, wt. %
50 55 60 7065 75
5
4
3
2
1
0
80 85
Coke, wt. %
5
15
20
25
0
10
0 2 3 54 61
Conversion,wt.%
Coke,wt.%
Bottoms,wt.%
Ga
soline,wt.%
Figure 7Alumina Matrix Catalyst Formulation Containing Mesoporous Rive Zeolite Matchedthe Activity and Had Improved Selectivity vs. a Commercial Alumina Matrix CatalystContaining Conventional Zeolite (at Equal, Moderate, ReO)
another in all tests. The degree of benefit hasvaried depending upon the overall formulation,and the feedstock used for the test, but direction-ally performance benefits in bottoms upgrading,gasoline yield, coke selectivity and/or olefinicityhave consistently been demonstrated.
Catalyst formulation work is continuing with the
objective of achieving the level of selectivityimprovement seen with pure zeolite powders. Asof today, comparing the catalytic results achievedwith pure powdered zeolites with those from for-mulated catalysts, we estimate that these excel-lent first improvements have the potential todouble when the full potential of the technology isrealized.
yield vs. coke. At constant 3% coke, the GRXcatalyst produced 1/3 lower bottoms relative tothe catalyst containing conventional zeolite (5%vs. nearly 8%).
Figure 8 below shows a similar comparison forGRX and conventional zeolite-containing alumi-na matrix catalysts at higher rare earth content.
Again catalyst activities were equal, but at higherrare earth level there was a significant gasolineyield advantage for the GRX catalyst withmesoporous Rive zeolite, along with improvedbottoms cracking and coke selectivity.
Overall, Rive mesoporous zeolites in differentcatalyst formulations tested to-date have consis-tently showed selectivity benefits in one form or
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GRACE DAVISON CATALAGRAM 11
53
69
77
85
45
61
25
22
19
16
13
10
55
50
45
40
35
50 55 60 7065 75 80 85
50 55 60 7065 75 80 850 3 6 129
Cat/Oil Ratio
Conversion, wt. %
Conversion, wt. %
50 55 60 7065 75
6
5
4
3
2
1
0
80 85
Conversion, wt. %
Conversion,wt.%
Coke,wt.%
LCO,wt.%
Gasoline,wt.%
Catalyst A GRX Catalyst
Figure 8Alumina Matrix Catalyst Formulation Containing Mesoporous Rive Zeolite Matchedthe Activity and Had Improved Selectivity vs. a Commercial Alumina Matrix CatalystContaining Conventional Zeolite (at Equal, High, ReO)
Economic Value Creating $0.79 per Barrel inthe Refinery
Because of the complex inter-relationshipbetween different units in a refinery and with eco-
nomic factors like crude pricing and the valuespread between feed and cracked products, it ischallenging to relate catalyst performance torefinery value. Rive Technology has used indus-try-standard AspenTech PIMS and KBCProfimatics modeling tools to bridge the gapbetween lab test results and economic value tothe refiner.
The analytical process is shown in Figure 9, below.ACE testing data measured at either CPERI orGrace Davison is processed using eitherProfimatics FCC-SIMTM process simulation soft-ware, or a proprietary kinetic model developed by
Rive Technology to produce catalyst performancefactors that, in turn, are converted to Profimaticscatalyst factors. Shift vectors generated withProfimatics are then input to a PIMS model of astandard reference refinery and the operation isoptimized. Sensitivity analyses have been run onvariables such as crude or product pricing, thevalue spread between feedstocks and products,and different operating limits.
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12 ISSUE No. 109 / 2011
ACE Data
CPERI / Grace
Obtain comparative
catalytic results
Profimatics or
RIVE Kinetic
Tool
Use comparative results
to set up Profimaticscatalyst factors
Profimatics
Predict FCC
shift vectors
PIMS
Estimate RIVE economics
and impacts on refinery
operations
Key inputs:
Riser TFeed T
Feed Quality
Figure 9Process Flow for Refinery Value
To ensure that crude costs and refinery productpricing data are input into the PIMS model in aconsistent manner, correlations were developedbased on historic data. We found that the historiccost of each crude and the price for each refineryproduct could be predicted well using linear func-tions of the prevailing 3-2-1 Crack Spread andthe cost of West Texas Intermediate crude (WTI).Therefore, for any projected WTI cost and crackspread, the price of each crude and each productcould be setup systematically in the model.
The hypothetical reference refinery for thisprocess has a 150,000 bpd crude capacity with a42,000 bpd FCC unit. It has both sour and sweetcrude stills. Refinery constraints are listed below:
1. Sweet crude is at rate limit (sour crude rateis usually not a limit, but can be set ifdesired)
2. Naphtha hydrotreater is feed limited (i.e.reformer naphtha feed treater)
3. FCC is coke limited4. Hydrocracker is at rate limit
5. Coker is at rate limit6. Product blending specs
Catalyst factors and shift vectors for the exampleanalysis are based on the GRX/Commercial cata-lyst comparison summarized in Figure 7. Crudeprice is set at $75/bbl of West Texas Intermediate(WTI) based on the 2 year average spot price
March 2009 thru February 2011. The crackspread is assumed to be $10/bbl; which is consis-tent with long range projections from the EnergyInformation Administration (EIA). Later we willshow the impact of changes in crude price andcrack spread on the economics.
Table II show the PIMS estimates for 2 operatingcases. In Case 1 crude rates were allowed tofloat within the unit constraints of the referencerefinery. In Case 2 crude rates were constrained
to the levels optimized for the base catalyst case.
Case 1 shows that increased economic valueresults from the following factors:
1. The combination of improved coke selectivityand reduced gas selectivity for the GRX catalystwith Rive mesoporous zeolite allows both thequality of the feed to the FCC unit to be reducedand reactor top temperature to be increased 17Fwhile keeping within the FCCU coke limit.
a. Coker Distillate is rerouted from the FCC to
the distillate hydrotreater, which augmentsand improves diesel blending stock andmakes the FCCU feed heavier.
b. Sweet crude train is limited, but to make updiverted FCCU feed and to provide moreblend stock for higher quality productscoming from the FCCU, more sour crude isrun. Naphtha cut point is decreased to
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GRACE DAVISON CATALAGRAM 13
Refinery Throughput
Refinery Profitability
Refinery Products:
LPG
Gasoline
DistillatesFuel Oil
FCC Riser Temperature
FCC Rate
FCC Yields:
Conversion
Gas
C3+ C4 Olefins
C3+ C4 Non-Olefins
Gasoline
Distillate
Bottoms
Coke(constant max coke rate constraint)
Parameter
+5.3 vol.%
+0.79 $/bbl crude
+0.3 vol.% of crude
+1.0 vol.% of crude
+3.8 vol.% of crude+0.3 vol.% of crude
+17F
-1.8 vol.% of crude
+3.8 wt.%
+0.6 wt.%
+1.2 wt.%
+1.6 wt.%
+0.2 wt.%
-2.2 wt.%
-1.6 wt.%
+0.2 wt.%
Case 1:
Optimized
Crude Rates
Case 2:Crude Rates
Constrained to
Base Case
NA
+0.47 $/bbl crude
+0.2 vol.% of crude
+0.3 vol.% of crude
+2.7 vol.% of crude-2.6 vol.% of crude
+11F
-2.0 vol.% of crude
+4.4 wt.%
+0.6 wt.%
+1.2 wt.%
+1.7 wt.%
+0.8 wt.%
-2.4 wt.%
-2.0 wt.%
+0.1 wt.%
Table IIIncremental Value of Improved Catalytic Selectivity from GRX FCC CatalystAll data shown are relative to base case (not shown)
stay within the reformer naphtha pretreaterfeed limit, thereby swinging more materialto kero (jet).
c. FCCU feed rate decreases 1.8%, and feedquality is reduced.
d. Increased riser top temperature results inincreased FCCU conversion and alsoincreases the octane and olefin content of
the cracked products. Negative value bottoms fall 15%.
2. Feed to the alkylation unit increases as aresult of greater olefins from the FCCU and
together with the increased octane from theFCCU, total octane barrels is sustained.3. Added jet from crude allows more FCChydrotreated heavy naphtha to be blendedinto diesel instead of jet.4. Hydrocracker is at its maximum feedrate,but the unit is able to shift yields to morenaphtha and less distillate due to increased
diesel from both FCC hydrotreated heavynaphtha and coker distillate.5. Reformer pretreater is limited, but 2.1%
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RiveTM
ZeoliteUplift,
$/bblCrude
1050
0.9
0.8
0.7
0.6
0.5
0.4
1.2
1.1
1.0
2015
WTI = $63
WTI = $75
WTI = $87
Crack Spread, $/bbl
Figure 10Improved Profitability from FCC Catalyst Containing Rive MesoporousZeolite as a Function of Crude Cost and Crack Spread
more reformate is produced due to moreHydrocracker naphtha production (whichdoes not need to go through the constrainedpretreater).
The net result of these changes, shown in TableII, is a 5.3% increase in refinery throughput with1.0% coming in gasoline and 3.8% in distillates.
The net value of these improvements is $0.79/bbl($118,000/day, or $43,000,000/yr).
Case 2 in Table II focuses on the value to theFCCU alone by constraining the refinery feed rateto base case levels. Consequently the spillovervalue to other units is diminished, but there is stillan increase in overall distillate and gasoline yieldsof 3.0% of the crude rate, and the FCCU experi-ences a 2 wt% drop in bottoms yield. Increasedgasoline octane and olefins yields also help sus-tain octane-barrels.
The values in Table II are based upon a crudeprice of $75/bbl and a crack spread of $10/bbl.Figure 10, below, shows the impact of changes tothese values on the increased profitability of Case1. It plots the value uplift in $/bbl of crude vs.
crack spread ($5/bbl to $15/bbl), and it displaysthree lines representing WTI crude prices of$63/bbl, $75/bbl, and $87/bbl. This range repre-sents the 10% and 90% points in the distributionof monthly running average WTI prices sinceMarch 2009 (see reference viii).
The graph shows that value uplift due to the
improved selectivity of GRX catalyst containingmesoporous Rive zeolite increases nearly lin-early with crack spread and roughly the same withincreases in crude price. It is highly profitable inall combinations within the explored range. Evenunder the least favorable condition of $63/bblcrude price and $5/bbl crack spread, the uplift isworth $0.52/bbl crude (ca. $28,000,000/yr). At themost favorable conditions the value uplift is$1.04/bbl crude, or ca. $57,000,000/yr. While it isnot shown, sensitivity analysis also indicates thatthe value uplift due to improved FCC catalyst
selectivity is approximately linear with refinerysize.
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GRACE DAVISON CATALAGRAM 15
Commercialization
Manufacturing of the first FCC catalyst from thisjoint program between Grace Davison and RiveTechnology is now moving from the pilot scale tofull commercial production. Thousands of poundsof Rive Y zeolite have been produced at thepilot plant of Graces Curtis Bay, MD manufactur-
ing facility, and, as you can see from Figure 11,below, its performance matches that of smallerscale materials made in Rive's Princeton NJ labo-ratory. Figure 11 compares two catalysts madeusing the same formulation and rare earth level,but one catalyst contained Rive zeolite that wasprocessed in the laboratory and the other con-tained Rive zeolite that was produced in thepilot plant.
Figure 11 shows that catalyst made with pilot plantRive zeolite was more active and had equalselectivity compared to catalyst made using lab-produced Rive zeolite. Continuous calcinationat the tech center allowed for more uniform stabi-lization of the zeolite which, in turn, produced amore crystalline and more hydrothermally stableproduct. At equal zeolite content the pilot plant
catalyst had a steamed zeolite surface area of190 m2/gm compared to 160 m2/gm for the cata-lyst with lab produced zeolite. Consequently, thepilot plant catalyst had about 25% higher activity(i.e., pilot plant zeolite catalyst achieved 75% con-version at 5.5 cat/oil vs. 7 cat/oil for the lab cata-lyst).
Lab Zeolite Pilot Plant Zeolite
65
75
80
85
60
70
2 3 4 65
Cat/Oil Ratio
Co
nversion,wt.%
55
507 8 109
55
50
45
40
35
50 55 60 7065 75 80 85
Conversion, wt. %
G
asoline,wt.%
Conversion, wt. %
50 55 60 7065 75
5
4
3
2
1
0
80 85
Coke,wt.%
13
19
22
25
10
16LCO,wt.%
50 55 60 7065 75 80 85
Conversion, wt. %
28
Figure 11Scale-up of Rive Zeolite Manufacturing Process at the Grace Davison TechnicalCenter Produced Excellent Quality
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16 ISSUE No. 109 / 2011
Otherwise, the two catalysts were identical.Figure 10 shows that there were no differences ineither the gasoline, LCO, or coke selectivities ofthe two catalysts.
Based on these excellent results, plant modifica-tions to accommodate the Rive process are inprogress, and a first refinery trial is scheduled for
later in the spring of 2011.
What's Next?
Along with FCC catalysts based upon Y zeolite,Rive and Grace Davison plan to introduce meso-porous ZSM-5 based catalysts and additives forcracking. Laboratory progress is well along onthese materials, and, if things go as expected, firstresults should be ready for publication by late thisyear or early in 2012.
References
1. barry.speronello@rivetechnology.com
2. Javier Garcia-Martinez is also a Professor of Inorganic
Chemistry at the University of Alicante (Spain):
javier@rivetechnology.com
3. allen.hansen@clinchain.com
4. ruizhong.hu@grace.com
5. Ying, Jackie Y and Garcia-Martinez, Javier, US Patent
7,589,041, Sept. 15, 2009
6. Product of KBC Advanced Technology, Houston, Texas
7. Product of Aspen Technology, Inc., Burlington, Massachusetts
8. Cushing OK WTI average spot price March 9, 2009 thru
February 25, 2011, www.eia.doe.gov
9. Energy Information Administration, Petroleum Analysis &
Projections, U.S. Department of Energy, www.eia.doe.gov
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GRACE DAVISON CATALAGRAM 17
REp RTM
The Development ofRare-Earth Free FCC Catalysts
Colin Baillie
Marketing Manager
Grace Davison
Refining Technologies
Worms, Germany
Rare-earth metals are an impor-tant component of FCC cata-lysts, as well as being a key rawmaterial for many strategic
industries with applications rang-ing from military devices to elec-tronic components. In addition,they are essential constituents innewly evolving green technolo-gies, such as hybrid cars andwind turbines. Rather ironically,rare-earth metals are not so
rare, however they tend to beconcentrated in hard to extractore deposits. As a result, theworlds supply comes from only
a few sources; China aloneaccounts for 95% of the worldsrare-earth metal output. Recentexport quota restrictions on rare-earth metals from China havecaused the price of rare-earthmetals to rapidly rise. Becauseof these new market forces, we
present here our progress in thedevelopment of rare-earth freeFCC catalysts.
Grace Davison has a long histo-ry of providing innovation in thedevelopment of FCC catalysts,including the addition of rare-earth metals to stabilize the zeo-lite Y component of the FCCcatalyst, which was revolutionaryfor catalytic cracking1. Grace
Rosann K. Schiller
Senior Marketing Manager
Grace Davison
Refining Technologies
Columbia, MD USA
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18 ISSUE No. 109 / 2011
also has a successful history ofdeveloping rare-earth free FCCcatalysts as shown in Figure 1.We introduced new catalystsand zeolite components thatenhanced gasoline octane in the1980s and 1990s, delivering
activity and stability without theuse of rare earth. The RE free
zeolites were used in over 85%of our catalysts in North Americaat the time. Later in the 1990sGrace developed Z-21, a rare-earth free stabilized zeolite Y.Based on this new technologythe NEXUS catalyst family wascommercialized in 1997, as arare-earth free catalyst family forlow-metal feed applications.NEXUS catalyst has since beenused in 10 applications2,3.
This article will describe com-mercial experience of the
NEXUS catalyst family, as wellas introduce several new rare-earth free catalyst families.These include REsolution andREBEL catalysts based on theexisting Z-21 zeolite, as well as
REactoR, REplaceR andREduceR catalysts based onthe Z-22 zeolite, which is anewly developed rare-earth freezeolite.
Commercial Experience UsingNEXUS Catalysts
In 2008, a refiner conductedback-to-back catalyst evalua-tions comparing NEXUS cata-lyst to a competitive rare-earthbased FCC catalyst. The feedproperties and operating param-eters for both periods were simi-lar. The Ecat Gas and HydrogenFactors during the back-to-backtesting are shown in Figures 2and 3, respectively. As can beclearly seen, NEXUS catalyst is
more selective at constant nickelequivalents than the competitiveoffering.
The FCC product yields obtainedduring back-to-back testing areshown in Table I. NEXUS cata-lyst provided higher conversion(2.8 wt.%), lower hydrogen yield
(0.04 wt.%), a lower dry gasyield (0.5 wt.%) and a highergasoline yield (5 wt.%). To sum-marise, the refiner consideredthe NEXUS catalyst trial to be acomplete success, realizing abenefit of approximately 1 million/year. The refinery remains onNEXUS catalyst to this day.
New REsolution andREBEL Catalyst FamiliesBased on Z-21 Zeolite
Recently, Grace Davison hasrenewed efforts to develop newrare-earth free catalysts. Thishas involved further formulationdevelopment by combining therare-earth free Z-21 zeolite withnew matrices, resulting in the
new families of REsolutioncatalysts and REBEL cata-lysts.
Rare-earth free REsolutioncatalysts are intended for low-metal feed applications, and rep-resent a further improvement onNEXUS catalyst performance.
1964
Graceinvents
USY
1976
Introduction
of REUSY
1990
Z14GRE free
zeolite
2010
Gracelaunches
Z-22RE free
zeolite
1991
XP-L
RE free
catalystseries
2008-2010
Significant
R&D effort
begins on REreplacement
1997
Grace
develops
NEXUS
catalystbased on
Z-21 RE
free
zeolite
Figure 1Graces Zeolite Innovation History
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GRACE DAVISON CATALAGRAM 19
Within each family ofREsolution catalysts, the abili-ty to independently adjust theactivity and selectivities of zeo-lite and the matrix, as well as theratio of zeolite/matrix activityallow for a tremendous degreeof formulation flexibility. For low-
metal applications REsolutionwill match/improve the perform-ance of standard rare-earthbased catalysts. Table II, showsACE pilot plant testing (CPS-3deactivation, no metals) compar-ing REsolution and NEXUScatalysts. It can be seen thatREsolution provides higherconversion and LPG olefinsyield, as well as similar gasolineyield, bottoms upgrading and
coke. Several trials ofREsolution catalysts are cur-rently taking place in Europe.
Further R&D work has provideda new rare-earth free high matrixcatalyst system for FCC applica-tions. REBEL catalyst, formu-lated with Z-21, demonstratessimilar activity and selectivity asMidas 100 catalyst, and is nowunder development (Table III).
Graces Latest ZeoliteInnovation Rare-Earth FreeZ-22 Zeolite
Most recently, Grace Davisonhas achieved a breakthroughwith a proprietary stabilizationprocess and a unique treatmentstep to boost acidity, resulting inZ-22, a state-of-the-art rare-earth free zeolite. Relative toREUSY, Z-22 provides equiva-
lent activity, higher LPG olefinsand gasoline octane, at constantbottoms and coke make, asshown in Table IV.
Ni Equivilents (Ni+V/4), ppm
3.5
3.0
2.5
2.0
1.5
1.0
0.5
600 700 800 900 1,000 1,100 1,300
0
1,4001,200
Competitor
NEXUSCatalyst
Figure 2Ecat Gas Factor of NEXUS Catalyst vs. Competitor
Ni Equivilents (Ni+V/4), ppm
0.25
0.20
0.15
0.10
0.05
600 700 800 900 1,000 1,100 1,300
0
1,4001,200
Competitor
NEXUSCatalyst
Figure 3Ecat Hydrogen Factor of NEXUS Catalystvs. Competitor
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20 ISSUE No. 109 / 2011
Z-22 zeolite has been success-fully produced in our manufactur-ing plants. Several new catalystfamilies utilizing Z-22 are nowbeing introduced for hydrotreat-ed or low to moderate feed-metal applications, with onecommercial trial currently under-
way in North America.
The introduction of rare-earthfree catalysts that utilize the Z-22 zeolite is also being plannedin Europe. For example,REactoR catalyst utilizes theZ-22 zeolite, but also incorpo-rates the processing technolo-gies used in NADIUS catalyst(a rare-earth based catalyst forlow-metal feed applications).
ACE pilot plant testing (CPS-3deactivation, metals free)demonstrates that both catalystsshow similar selectivities interms of dry gas, coke and bot-toms upgrading, whilstREactoR catalyst provideshigher yields of LPG olefins atthe expense of some gasolineyield (Table V).
REplaceR catalyst is anothernew rare-earth free catalyst fam-
ily that is based on the Z-22 zeo-lite, but this catalyst incorporatesthe processing technologiesused in NaceR catalyst(another rare-earth based cata-lyst for low-metal feed applica-tions). ACE pilot plant testing(CPS-3 deactivation, metalsfree) comparing REplaceRwith NaceR show thatREplaceR provides similarlyhigh activity, slightly higher LPG
olefin yields and similar bottomsupgrading and coke yield.
These ACE pilot plant resultsdemonstrate that for low-metalapplications REactoR andREplaceR catalyst are suitablerare-earth free alternatives to
Cat-to-oil
LPG olefins, wt.%
Gasoline, wt.%
HCO, wt.%
Coke, wt.%
4.9
13.7
49.4
10.0
2.3
4.5
14.2
49.4
9.8
2.2
ACE Yields at Constant Conversion
(CPS-3 deactivation, metals free)
NEXUS
Catalyst
REsolutionTM
Catalyst
Table IIACE Pilot Plant Testing Comparing
REsolutionTM
Catalyst with NEXUS
Catalyst
Cat-to-oil
Dry Gas, wt.%
Propylene, wt.%
Butylenes, wt.%
Gasoline, wt.%
Bottoms, wt.%
Coke, wt.%
5.8
1.8
3.5
5.2
46.6
9.6
4.2
5.5
1.8
3.5
5.4
46.8
9.5
4.3
MIDAS-100
ACE Yields at Constant Conversion
(CPS-3 deactivation, 3000 ppm Ni+V)
REBELTM
Catalyst
Table IIIREBELTM Catalyst Delivers the Same Activity andSelectivity Over Resid Feedstock.
H2
Dry Gas (-H2S)LPG
Gasoline C5-210C
LCO 210-360C
MCB 360+ C
Coke
Conversion
Product Yields
0.03
3.6016.25
50.16
15.62
7.98
4.72
76.39
0.07
4.1218.19
45.20
18.72
7.68
4.56
73.60
Competitor Delta
-0.04
-0.52-1.94
4.96
-3.10
0.30
0.16
2.79
NEXUS-346
Table IFCC Product Yields Comparing NEXUS Catalyst witha Competitors Rare-Earth Based Catalyst
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GRACE DAVISON CATALAGRAM 21
established rare-earth basedcatalysts. Within these catalystfamilies the matrix type as wellas the zeolite/matrix ratio can bevaried. Additional formulationflexibility is possible, enablingfine tuning of the catalyst to suitFCCU-specific requirements
regarding activity and selectivity.REactoR and REplaceRcatalysts are also manufacturedwith the proprietary GraceDavison alumina-sol binder sys-tem, which ensures low particu-late emissions due to itsexcellent attrition resistance.
A Rare-Earth Free Catalyst forResid Feed Applications
Due to the additional demandsplaced on zeolite stability, thedevelopment of rare-earth freecatalysts for the resid feed sec-tor is much more challengingthan for the low-metal feed sec-tor. Rare-earth metals remainthe most effective vanadiumtrap. However, processing tech-nology involving metals resist-ance functionality has now beensuccessfully applied to catalystsystems containing the Z-21 and
Z-22 zeolites, resulting in theREduceR catalyst family.Although not fully equivalent tothe performance of benchmarkpure rare-earth based resid cata-lysts, REduceR catalyst canbe used as a blending compo-nent with a rare-earth basedresid catalyst, thus reducing theoverall rare-earth requirement.ACE pilot plant testing (CPS-3deactivation, 5,000 ppm Ni+V)
comparing a rare-earth basedNEKTOR resid catalyst andthe same catalyst containing30% of REduceR catalyst areshown in Table VII. To sum-marise, REduceR catalyst, arare-earth free resid catalyst canbe blended with a rare-earthbased resid catalyst to provide
Cat-to-oil
Dry Gas, wt.%
Propylene, wt.%
Butylenes, wt.%
Gasoline, wt.%
Bottoms, wt.%
Coke, wt.%
Z-22
6.6
1.5
4.6
11.0
52.0
6.7
2.3
6.8
1.4
4.3
10.4
53.0
6.8
2.2
REUSY
ACE Yields at Constant Conversion
Table IVZ-22 Delivers the Same Equivalent Activity andSelectivity Without Rare Earth
Conversion, wt.%
LPG Olefins, wt.%
Gasoline, wt.%
Bottoms, wt.%
Coke, wt.%
75
14.6
51.0
10.3
1.7
75
15.3
50.3
10.3
1.6
NADIUS
CatalystReactorRTM
Catalyst
CPS-3 Deactivation, Metals Free
Table VACE Testing Comparing NADIUS withReactoRTM Catalyst
Conversion, wt.%
LPG Olefins, wt.%
Gasoline, wt.%
Bottoms, wt.%
Coke, wt.%
75
13.7
50.4
10.0
2.6
75
14.3
50.0
9.9
2.1
NaceRTM
Catalyst
ReplaceRTM
Catalyst
CPS-3 Deactivation, Metals Free
Table VIACE Testing Comparing NaceRTM Catalystwith ReplaceRTM Catalyst
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22 ISSUE No. 109 / 2011
similar performance in the keyareas of activity, bottomsupgrading and coke yield. Graceis continuing R&D work to devel-op a rare-earth free catalyst withthe stability and performance toallow the complete elimination ofrare-earth based grades in resid
applications.
Summary
Grace has a long history of inno-vation in rare earth free cataly-sis. In the 1980s and 1990s, alarge proportion of Graces cus-tomers in North America utilizedRE free zeolite in their catalystformulations to maximize FCCgasoline octane. In 1997,
NEXUS
catalyst, formulatedwith Z-21, a rare-earth free zeo-lite, was introduced for low-metal feeds. In 2008, R&Dactivities were intensified todevelop new rare-earth free cat-alysts. This has resulted in sev-eral new catalyst families for thelow-metal feed sector as well asseveral promising leads for residcracking:
REsolution catalyst:contains rare-earth free Z-21zeolite in combination with anew matrix.
REactoR catalyst: containsthe newly developed rare-earth free Z-22 zeolite withthe application of theprocessing technologiesused in NADIUS catalyst.
REplaceR catalyst:contains the newly
developed rare-earth freeZ-22 zeolite with theapplication of the processingtechnologies used inNaceR.
REduceR catalyst, a rare-
earth free resid catalyst,which can be blended at a30% level into rare-earthbased resid catalysts withoutsignificant performancedeterioration in residapplications.
REBEL catalyst, a highmatrix catalyst formulatedwith Z-21, yields similarperformance as Midas 100catalyst after deactivation
with metals.Grace Davison RefiningTechnologies has respondedquickly to the issues of rare-earth price and availability bydeveloping these new rare-earthfree catalysts, in order to relievethe cost pressure on customerswithout incurring performancepenalties. The developmentsinvolving the new Z-22 zeolitewill require modifications to our
manufacturing plants, which willlimit the short-term availability ofsome rare-earth free catalystfamilies. If you are interested inthese new rare-earth free cata-
lyst families we suggest that you
contact your Grace technicalsales and services representa-tives to find out which catalyst ismost suitable for your operation.
References
1. Wormsbecher, R. et al. The Role of
Rare Earths in Fluid Catalytic Cracking,
Catalagram 108
2. Grace Davison Catalagram, European
Edition 1999
3. Grace Davison Catalagram, European
Edition 2010
4. Maher,P.K. and McDaniel, C.V. "Zeolite
Z-14US and method of preparation thereof.
Patent 3,293,192. 20 December 1966
Cat-to-oil
LPG Olefins, wt.%
Gasoline, wt.%
Bottoms, wt.%
Coke, wt.%
4.5
13.8
51.0
7.2
5.5
5.3
13.9
50.9
7.0
5.3
NEKTORTM
Catalyst70% NEKTOR
TM
30% ReduceRTM
ACE Yields at Constant Conversion
(CPS-3 deactivation, 2500/4500 ppm V/Ni)
Table VIIACE Testing Comparing NEKTORTM Catalyst withNEKTORTM/ReduceRTM Catalysts (70/30)
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GRACE DAVISON CATALAGRAM 23
Grace introduces two new SOxadditives to mitigate the dramat-ic price escalation in rare-earth.
These products build upon theproven effectiveness of SuperDESOX additive. SuperDESOX OCI additive is the firstgeneration of low RE SOx addi-tive from Grace. Super DESOX
OCI additive has proven in com-mercial scale trial to be as effec-tive as the Super DESOX
additive, resulting in on par pick-up factor efficiency.
Additionally, Grace has sincedeveloped Super DESOX MCDadditive, a second generation ofSOx additive with even lowerrare earth. Lab testing suggeststhat it is possible to attain a suit-able and cost effective balance
between SOX transfer abilityand additions. Super DESOX
MCD additive will be in multiplecommercial trials in the secondquarter of 2011.
Finally, Grace is activelyresearching rare earth free SOxadditive, Super DESOX CeROadditive. We will keep youapprised of our progress towardscommercialization.
A New Generation ofSuper DESOX Additive
Super DESOX additives have similar pick up factors
PickUpFactor +5
+10
Base
-5
-10
Super DESOXAdditive Super DESOXOCI Additive
Figure 2Super DESOX OCI Additive - Commercial Data
Flue
GasSOx,ppm
0
5
15
20
10
Time Scale (120 Days)
Time Scale (120 Days)
PercentofTotalAdditions
20
30
10
Super DESOX OCI Additive
maintained flue gas
SOx emissions
below 25 ppm
Super DESOXAdditive
Super DESOXOCI Additive
Figure 1Super DESOX OCI Additive - Commercial Data
Eric GriesingerMarketing Manager, Grace Davison Refining Technologies, Columbia, MD
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ResidUltraTM: Low RE CatalystTechnology for ResidProcessing Applications
Sudhakar Jale, Ph.D.
Senior Marketing
ManagerGrace Davison
Refining Technologies
Columbia, MD
Rare earth oxide is one of thekey components of FCC cata-lysts improving the stability offaujasite zeolite, scavengingfeedstock metals and enhanc-ing the selectivity towardsdesired products. The pricesof rare-earth compounds con-tinue to skyrocket due toChinas restricted exportquota system and pending
24 ISSUE No. 109 / 2011
environmental regulations,causing a rise in catalystprices by more than 50%. Thecatalyst market accounts forabout 20% of global rareearth supply in 2010. Eventhough this share is expectedto drop to about 15% due tothe growth in other markets,particularly magnets, thedemand for rare-earth by vol-ume will increase by about
Ruizhong Hu, Ph.D.
Manager of Research
and Tech SupportGrace Davison
Refining Technologies
Columbia, MD
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70 72 74 7876 80 70 72 74 7876 80 82
45
47
49
51
0
0.1
0.2
0.3
Conversion % Conversion %
ResidUltraTM Catalyst ResidUltraTM Catalyst
IMPACT
CatalystHydrogen,wt.%
Gasoline,wt.%
IMPACT
Catalyst
Figure 2ResidUltraTM Catalyst Makes Slightly Less Hydrogen and Similar Gasoline Content
Conversion %
70 72 74 7876 80 70 72 74 7876 80
4
6
8
10
4
6
8
10
IMPACT Catalyst
Conversion %
ResidUltraTM Catalyst ResidUltraTM Catalyst
CattoOilR
atio
Coke,wt.%
IMPACT Catalyst
Figure 1ResidUltraTM Catalyst Has Slightly Higher C/O Ratio and Improved Coke Selectivity
26 ISSUE No. 109 / 2011
Summary
The ACE results clearlydemonstrate thatResidUltra has equivalent
or better performance thanIMPACT catalyst when test-ed over resid feed. The 40%reduction in RE content is anexcellent economic incentivefor refiners processing residto switch to this novel catalysttechnology.
References
1. Chegwidden, J. and Kingsnorth, D.J.,
Rare Earths: Facing the Uncertainties of
Supply 6th International Rare Earths
Conference, Hong Kong, November 2010.
2. Purnell, S., IMPACT: A Breakthrough
Technology for Resid Processing
Catalagram #93, 2003.
3. Cheng, W.-C., Nee, J.R.D. and
Neuberger, D., Maximizing Refinery
Profitability with Next Generation Alumina-sol
FCC Catalyst Technologies IMPACT, LIBRA,
POLARIS, and PINNACLE, NPRA Annual
Meeting, AM05-068, San Francisco, 2005.
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GRACE DAVISON CATALAGRAM 27
Worldwide FCC EquilibriumCatalyst TrendsAssessing the First Decade
of the 21st Century
Olivia A. Topete
Technical Sales
RepresentativeGrace Davison
Refining Technologies
Houston, TX
The Analytical ServicesCenter (ASC) Tech Servicegroup at Grace Davisonreceives equilibrium fluidcracking catalyst (Ecat) sam-ples from refineries spanningthe globe. On average,Grace receives over 200 Ecatsamples each week from theworlds FCCUs. The result-ing information is of criticalimportance for the FCC unit
engineer, who is responsiblefor continuous optimizationand troubleshooting of his/heroperation.
The subsequent discussionhighlights the trends observedin Ecat properties over thelast ten years. The datareflected is not exclusive toGrace Davison products.Samples containing competi-
tive catalyst, additives, andproducts are also included.
As the refining industry as awhole is challenged by thesupply constraints of rareearth, it is interesting to seethe trends in properties overthe last ten years. Ecat con-taminant levels maintain theirupward trend as the world
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moves to more and moreresid processing. Rare-earthremains the most effectivemeans to maintain activityand selectivity in severe oper-ations. However, we areworking diligently to reducethe rare-earth content of the
catalyst, and maintain per-formance. At the same time,refiners need to consider theeconomic tradeoffs associat-ed with rare-earth reductionsand assess what processchanges can be made in theunit operation to offset anyresultant performance differ-ences.
Vanadium
Figure 1 illustrates the trendin vanadium over the firstdecade of the 21st century.With the exception of 2000 to2001, the Asia Pacific marketunfailingly maintains the high-est levels of contaminantvanadium. Interestingly, whileall other markets have experi-enced an increase in averagevanadium levels in the latterpart of the decade, the Asia
Pacific market average hasexperienced a sudden drop ofalmost 20% from 2009 to2010. In its entirety, the aver-aged FCC world contaminantlevel has been consistent in aband centered around 2,000wppm. The North Americanmarket continues to demon-strate the lowest levels ofvanadium in the world (1,626ppm).
Nickel
Falling for the first time below3500 wppm, the Asia Pacificmarket reliably maintains thetop ranking spot for averagenickel level in Ecat. Asshown in Figure 2, there is a
201020082006200420022000
3250
3000
2750
2500
2250
2000
1750
1500
Year
V,ppm
Asia Pacific
Europe
Latin America
North America
World Wide
Figure 1Average Vanadium by Region for 2000 to 2010
201020082006200420022000
4500
4000
3500
3000
2500
2000
1500
1000
Year
NI,ppm
Asia PacificEurope
Latin America
North AmericaWorld Wide
Figure 2Average Nickel by Region for 2000 to 2010
28 ISSUE No. 109 / 2011
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tremendous differentialbetween Asia Pacific and therest of the world. The gapnever closes to less than1,600 wppm. The growth inresid processing in Asia willcontinue this trend in years tocome. As with vanadium, the
Asia Pacific market hasdemonstrated a decreaseover the past few years whileall other markets have showna small increase. Similar tovanadium, the North
American market maintainsthe lowest average nickel lev-els (1,363 ppm).
Iron
The movement in averageiron level on industry Ecat,shown in Figure 3, can bestbe explained as diverse. TheNorth American market hasconsistently maintained thehighest average levels of ironoverall increasing from 0.52wt.% to 0.6 wt.%. Beginningin 2002, the European aver-age iron level began a steadydescent from 0.52 wt.% to0.46 wt.% and has remained
at this level since 2007. Theworldwide average indicates adownward trend overall forthe last three years.
Calcium
In 2004, most of the industryEcat averages faced a steady4 to 5 year climb in calcium.
Asia Pacific led the packwhen average levels rose
from 0.09 wt.% to 0.2 wt.%.Figure 4 shows that duringthe past year, the worldwidetrends have tilted downwardand will likely continue in thatdirection.
201020082006200420022000
0.625
0.600
0.575
0.550
0.525
0.500
0.475
0.450
Year
Fe,
wt.%
Asia Pacific
Europe
Latin America
North America
World Wide
Figure 3Average Iron by Region for 2000 to 2010
201020082006200420022000
0.20
0.15
0.10
0.05
Year
CaO,wt.%
Asia PacificEurope
Latin America
North AmericaWorld Wide
Figure 4Average Calcium by Region for 2000 to 2010
GRACE DAVISON CATALAGRAM 29
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Sodium
With few exceptions, sodium(Figure 5) has been steadilytrending down for over tenyears. Latin America contin-ues to maintain the highestvalues with a median value
over the past three years of0.35 wt.%. North Americadropped to a decade averagelow of 0.26 wt.%.
The average vanadium andnickel levels that characterizethe Asia Pacific market indi-cate that this region continuesto process feeds that arevastly different from the restof the world. As alluded to
earlier, the average Ecatresults from this territory con-tinue to report the highestaverage levels for 80% of theprimary FCC catalyst contam-inants. Up until 2008, mostworldwide contaminant trendswere directionally consistent.The coming years will beexciting as the industry ischallenged to process higheramounts of discounted feed-stocks to maintain profitability.
Activity
Until 2004, most of the indus-try saw a steady climb in Ecatactivity. As indicated byFigure 6, over the next fouryears, activity trends flattenedwith slight periodic increases.In 2009, activity numbersregained momentum to reachdecade highs in all but the
European market. With thehighest numbers amongst allfour regions, North Americaexperienced an average 3.4number increase from 69.9 to73.3 over the last decade.The world wide average
201020082006200420022000
0.425
0.400
0.375
0.350
0.325
0.300
0.275
0.250
Year
Na,wt.%
Asia Pacific
Europe
Latin America
North America
World Wide
Figure 5Average Sodium by Region for 2000 to 2010
201020082006200420022000
74
73
72
71
70
69
68
67
66
Year
MAT,wt.%
Asia PacificEurope
Latin America
North America
World Wide
Figure 6Average MAT Activity by Region for 2000 to 2010
30 ISSUE No. 109 / 2011
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disparity amongst regions. In2005, the difference betweenthe Latin American andEuropean regions averaged0.04 . The European regionalso registered an averageunit cell size decade high forall regions at 24.32 . During
the latter part of the decade,market unit cell size began toconverge to an average 24.31
. The exception, the LatinAmerican region, remainsslightly lower at 24.30 butthe overall regional diver-gence is significantly reducedin comparison to years priorto 2005.
Particle Distribution
(0 to 40 microns)
In November 2009, Gracesroutine Ecat particle size testwas changed to new instru-mentation. The new particlesize properties no longerhave the micro-mesh factorsapplied and the results aredirectly from the equivalentspherical analysis model ofthe measurement data. As aresult, a significant shift in the
2010 data can be seen inFigure 9.
Nonetheless, previous yearsdata tells that while there islittle variance over time withineach region, there is substan-tial offset amid regions. Theworldwide average for 0-40particle size is 6%. Highaverage catalyst age or lowcatalyst additions per volume
of inventory will decrease the0-40 fraction and increaseaverage particle size.
Grace remains committed toproviding Ecat analyses as akey component of our techni-cal service package for cus-
201020082006200420022000
13
12
11
10
9
8
7
6
5
4
Year
0-
40,
wt.%
Asia Pacific
Europe
Latin America
North America
World Wide
Figure 9Average 0-40 wt.% by Region for 2000 to 2010
tomers. The historical resultsfor any unit can provide aninvaluable reference point fortroubleshooting activities orassessment of performance
deltas after major turn-arounds. Ecat results areavailable 24/7 on our cus-tomer website, www.e-cata-lysts.com. Contact your salesrepresentative to gain accessto your units sample resultsas well as a host of othertechnical literature and infor-mation.
32 ISSUE No. 109 / 2011
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GRACE DAVISON CATALAGRAM 33
GDNOXTM 1 Additive - Grace DavisonsNext Generation NOx ReductionAdditive
GDNOXTM 1 additive is the next generation NOx reduction additive for the FCC regenerator unit. Unliketraditional NOx reduction additives, GDNOXTM 1 additive utilizes a new technology platform that builds onthe success of DENOX, while allowing refiners the ability to achieve greater NOx reduction. And, unlikeearlier generation NOx reduction additives, GDNOXTM 1 additive greatly mitigates H2 and/or dry gas penal-ties. GDNOXTM 1 additive is formulated to reduce exposure from inflation in rare earth pricing.
As extensive pilot plant testing shows in Figure 1, refiners have the ability to incrementally improve NOxreduction, by upwards to 80%, with increased GDNOXTM 1 additive dosing rates. To achieve targeted NOxreduction, the recommended dos-ing rate for GDNOXTM 1 additive
typically ranges between 2.5 wt.%and 7.5 wt.% of catalyst inventory.
GDNOXTM 1 additive allows refin-ers to:
Meet local/federal NOxregulations,
Meet EPA constraintswithout the cost of capital,
Process feeds high innitrogen with greater
economic flexibility, Balance refinery wideNOx emissions, and
Maintain FCC throughput
Ask your Grace sales representa-tive for more information.
0
50
100
150
200
250
300
350
0 0.5 1 1.5 2 2.5 3 3.5 4
NO
(ppm)
Time (hr)
Base 2.5% GDNOXTM
1 Additive
5% GDNOXTM
1 Additive 10% GDNOXTM
1 Additive
Figure 1
Pilot Plant Testing: NOx Reduction With MultipleGDNOXTM 1 Additive Additions
292
287
287
GDNOXTM
1 AdditiveAddition Rate% of Inventory
Base LineNOx (ppm)
NOx After
GDNOXTM
1 AdditiveAddition (ppm)
Percentage NOxReduction/%
139
110
62
50
60
80
2.5% GDNOX 1
5.0% GDNOX 1
10.0% GDNOX 1
Eric GriesingerMarketing Manager, Grace Davison Refining Technologies, Columbia, MD
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34 ISSUE No. 109 / 2011
The refining industry is wellversed in the use of ZSM-5 lightolefins additives for the incre-mental production of propylenefor chemical and polymer appli-cations and butylenes for alkyla-tion unit feedstock. However,light olefins additives are alsocapable of providing significantflexibility in operating the FCCunit, providing additional eco-nomic benefits for the refiner.
Grace delivered incrementalprofitability to a refiner who tookan early turnaround on a catalyt-ic reformer. The refinery wasoctane short and there was noopportunity to increase riser tem-perature. Grace recommendedthe use of a light olefins additiveto boost the overall octane fromthe FCC complex. The use ofZSM-5 increases the yield of C3
and C4 olefins to feed the alky-lation unit and any other unitsdesigned to create gasolinerange material from FCC olefins.The effect of ZSM-5 on the con-version of gasoline olefins toLPG olefins can be seen inFigure 1.
The ability of ZSM-5 to increasethe light olefins yield from theFCC is due to the size and
shape of its micropores. Thesmall pores of ZSM-5 allow rapiddiffusion and cracking of lowoctane, linear hydrocarbons fromthe gasoline into LPG rangeolefins, leaving the gasoline rich-er in aromatics and henceoctane value.
Improving FCC Economics withLight Olefins Additives
OlefinsYield,
wt.%
2 3 4 5
Olefins Carbon Number
6 7 8 9
Base
ZSM-5 cracks C5+ gasoline range
hydrocarbon to propylene and butylenes
Base + ZSM-5
Figure 1The Effect of ZSM-5 on Olefins Distribution
As a result of ZSM-5 cracking,the incremental light olefins pro-duction from the FCC results inhigher alkylate yields. Alkylate isa refinery blending stream that ishigh in both motor and researchoctane. At the same time, theyield of FCC gasoline generallydrops at constant riser tempera-ture, but the octane is increased,with general increases rangingfrom 0.3 to 0.7 numbers.
When the total octane propertiesof the FCC gasoline and alkylateare added together, there is anincrease in the octane of the
total gasoline pool from the FCCcomplex. This is a valuable eco-nomic option when the FCC unitis running at reduced feed ratesand there is available capacity inthe alkylation unit. By varyingthe concentration of light olefinadditive in circulating catalystinventory, the refiner can take
advantage of available capacityin the alkylation unit while inde-pendently optimizing the riseroutlet temperature.This optionmay be especially helpful in thefall and winter, when higher LCOyields are generally desirable buta loss in volume gain across theFCC is not.
Grace Davison is the leadingsupplier of high activity, high sta-bility light olefins FCC additives.OlefinsMax, OlefinsUltra, andOlefinsUltra HZ additives arebeing used in over 70 FCC unitsworldwide. They continue to
provide economic value for therefiner by generating incrementalpropylene, additional feed foralkylation and an increase ingasoline octane.
Kristen WagnerMarketing Manager, Grace Davison Refining Technologies, Columbia, MD
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GRACE DAVISON CATALAGRAM 35
Introduction
The use of GSR (Grace SulfurReduction) technology in theFCC unit can reduce the desul-
furization required by the FCCfeed hydrotreater, resulting inlonger hydrotreater catalyst lifeand a lower severity operation.GSR products are used in bothshort term and long term appli-cations to preserve hydrotreatercatalyst life and postponehydrotreater outages.
Proper management of FCCfeed hydrotreater outages is
increasingly important as refin-ers rely heavily on hydrotreatingto meet gasoline sulfur limits,while trying to minimize operat-ing costs. Unfortunately, tightersulfur regulations are forcingrefiners to either expand FCCfeed hydrotreating capacity orincrease severity on their exist-
ing hydrotreaters and hydroc-rackers, resulting in more fre-quent turnarounds and higherexpenses.
Some methods to manage gaso-line pool sulfur limits during ahydrotreater turnaround includepurchasing low sulfur FCC feedor reducing FCC throughput.Both options place a greaterfinancial burden on the refiner.Other approaches have been tofind outlets for higher sulfurgasoline during a turnaround,but with continued global imple-mentation of sulfur regulations,
this option is becoming lessviable.
GSR Technologies
Grace has provided GSR tech-nologies to the industry for over17 years to reduce FCC gaso-line sulfur by up to 35%. These
technologies include D-PriSM
additive, SuRCA catalyst, GSR
5 additive, and NEPTUNETM cat-alyst. Grace GSR products arecurrently being used in all
regions of the world today. Asidefrom reduced hydrotreater sever-ity, other commercial benefits ofusing GSR technologiesinclude, FCC feedstock blendingflexibility and improved gasolineoctane (reduced naphtha posttreater severity).
Commercial Performance:GSR 5 During HydrotreaterTurnaround
Figure 1 is a commercial exam-ple of GSR 5 usage during andafter an FCC feed hydrotreaterturnaround. Coordinated effortswith Grace allowed the refiner tobaseload their inventory andachieve target sulfur reductionlevels within three weeks. The
Higher Profits withHigher SulfurKristen Wagner
Marketing Manager,
Grace Davison Refining Technologies,
Columbia, MD
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GRACE DAVISON CATALAGRAM 37
It has long been understood that optimum additive performance and unit stability in an FCCU are greatlyassisted by continuous and steady injection of FCC additives. The challenge has been further complicatedin recent years as refiners must now comply with multiple environmental regulations and depend upon sta-ble operation and product addition rates to do so. Grace Davisons newest loader, designed specificallyfor additive use, combines functionality and reliability with ease of use. The EZTMAdditive Loaders com-pact design and ability to load two additives simultaneously offers an EZTM solution to meet FCCU objec-tives.
The benefits of an EZTMAdditive Loader system:
Consistent control of additive injections Reliability with low maintenance requirements
Robust range of injection rates Accurate injection weight and record keeping ability Advanced Touch Screen control for user-friendly operation Compact pre-assembled skid mounted design for simple installation Fugitive dust containment (no environmental impact) Injection of two materials independently Direct connection to additive tote bins
More than just a loader:
Every EZTMAdditive Loader is tested prior toshipment in our test facility
Pre-installation training available at ourtest facility Extensive on-site start-up assistance and
operating/maintenance instruction On-line loader operations manual Interactive web-based troubleshooting guide Critical spare parts inventory maintained
Stable additive additions to the FCCU are an impor-tant part of achieving maximum FCCU profitability.As refiners move to meet more stringent product andenvironmental regulations, addition systems willbecome an essential part of the unit control. Grace
Davisons EZTMAdditive Loader system provides acost effective and reliable means of adding additiveson a continuous basis.
Grace Davisons EZTM AdditiveLoader Injection System
Compact footprint - 6 10 L x 4W x 74H
Weight - approximately 2,300 lbs
Capacity - approximately 3 ton/day
Ports - 2 inlet sources connect directly
to additive tote bins
Kelly StaffordTechnical Sales Support Coordinator, Grace Davison Refining Technologies, Columbia, MD
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38 ISSUE No. 109 / 2011
The benefits that hydrotreat-ing fluidized catalytic crackingUnit (FCC) feed has on prod-
uct yields and sulfur contentwere recognized some timeago and described in manyearlier publications2-5. Recentregulatory demands and thedrive towards clean fuelsresulted in a renewed interestin FCC feed hydrotreating tofacilitate compliance and sat-
Balancing the Need for Low SulfurFCC Products and Increasing FCC
LCO Yields by ApplyingAdvanced Technology forCat Feed Hydrotreating
isfy the need for improvedyields. To address theseneeds, Advanced Refining
Technologies LLC (ART)introduced the ApART
Catalyst System for FCC pre-treatment 6. This technologywas developed to provide sig-nificant increases in HDSconversion while at the sametime providing significantupgrading of FCC feedstock
quality and has been de-scribed in detail previously7.In essence, an ApART
Catalyst System is a stagedbed of high activity NiMo andCoMo catalysts where the rel-ative quantities of each cata-lyst can be optimized to meetindividual refiners goals andconstraints. ART has contin-ued to develop a betterunderstanding of the reac-
Brian Watkins
Technical Service Engineer
Advanced
Refining Technologies
Chicago, IL USA
Charles Olsen
Worldwide Technical
Services Manager
Advanced
Refining Technologies
Columbia, MD USA
David Hunt
North America FCC
Technical Manager
Grace Davison
Refining Technologies
Chicago, IL USA
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GRACE DAVISON CATALAGRAM 39
tions and kinetics involved inFCC pretreating, and throughits relationship with GraceDavison RefiningTechnologies, a detailed
understanding of the effectsof hydrotreating on FCC unitperformance. The complexityof combinations of catalystdesign and operating condi-tions for both the FCC feedhydrotreater and the FCC unitcontinues to present a signifi-cant optimization opportunityfor refiners to drive the com-bined operation to maximumproduct value.
It has been shown that boththe hydrotreating catalyst sys-tem and the operating strate-gy for the FCC pretreater arecritical to providing the high-est quality feed for the FCC8.In general, NiMo based cata-lysts produce FCC feed with
DeltaFCCYields,wt.%
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
Low Pretreat Severity:
HDS Mode
High Pretreat Severity:
PNA Mode
FCC Pretreater Catalyst Type
CoMo CoMoNiMo NiMo
Dry Gas Total C3's Total C4's Gasoline LCO Conversi on
Figure 1Impact of Pretreater Catalyst and Operating Severity
lower nitrogen and PolyNuclear Aromatic (PNA) con-tent than CoMo based cata-lysts. This shifts the FCCyields towards higher conver-
sion at the expense of LCOproduction. The operatingmode of the hydrotreater canalso be used to improve theFCC feed. Driving thehydrotreater to remove morenitrogen and PNA's (so-calledPNA mode of operation)results in an FCC feed whichagain shifts the FCC productstoward more gasoline andLPG production. This isshown in Figure 1, whichsummarizes the delta FCCyield at constant coke yieldsfrom an Advanced CatalyticCracking (ACE) pilot plantstudy comparing the effects ofhydrotreating FCC feed overa CoMo and NiMo catalyst.The data clearly show that
using a NiMo catalyst resultsin higher FCC conversionalong with higher gasolineyield compared to a CoMocatalyst for both low and highFCC pretreat severity.(Higher dry gas noted at high-er conversion and constant
reactor temperature is an arti-fact of pilot testing and is notobserved commercially.) Thedata also show the impact ofpretreater operating severity.
At high severity or PNA mode,there is a large increase inFCC conversion and corre-sponding increase in gasolineyield.
Of course, there are also sig-
nificant differences in hydro-gen consumption andpretreater cycle length for thedifferent modes of operation,and these costs need to bebalanced against the benefitsof increased FCC conversion.This is described in moredetail in other work8.
The FCC catalyst formulationis also an important factorthat can be tailored to shift
FCC yields and help maxi-mize profitability. Figure 2summarizes pilot plant datademonstrating the impact onyields of different FCC cata-lysts using a constant FCCfeed that was hydrotreatedover a NiMo catalyst with thepretreater operating in PNAversus HDS modes. Thedata show that significant dif-ferences in FCC conversion
and FCC product yields atconstant coke yield can beaffected by changes in FCCcatalyst technologies.
Much of the work investigat-ing the effects of FCC pre-treating on FCC performancehas emphasized gasoline pro-
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duction due to the prevailingeconomics of the time. Thegovernmental mandate forultra low sulfur diesel (ULSD)and the resulting increase indemand for these cleanerfuels prompted many refinersto increase LCO production
from the FCC unit to maxi-mize the mid-distillate pool.Several papers haveexplored ways to increaseFCC LCO by adjusting FCCcatalyst formulations andmodifying FCC operation9.Understanding the effectsthat this increased LCO pro-duction has on downstreamULSD operation and optionsfor dealing with it have been
explored in detail10
. Giventhe impact FCC pretreatinghas on the FCC performance
just described, the pretreaterclearly has a role to play inmodifying the FCC productslate to meet increasing distil-late demand.
In addition to changing eco-nomics, refiners are also look-ing at more stringentregulations on fuels which
often serve as an outlet forFCC LCO. LCO is blendedinto wide variety of mid-distil-late streams as summarizedin Figure 3. It can be sent toa hydrocracker to make highquality jet and kerosene prod-ucts, and if the refiner has thehydrotreating capacity avail-able, it can be sent to a dieselhydrotreater to produce ULSDor sent to higher sulfur prod-
ucts like fuel oil. A portion ofthe LCO may also be used ascutter stock or blended formarine diesel. Sulfur specifi-cations on many mid-distillatestreams are expected to getmore stringent, and Figure 4
Low Pretreat Severity:
HDS Mode
High Pretreat Severity:
PNA Mode
FCC Catalyst Type
Type 1 Type 3Type 2 Type 4
Dry Gas Total C3's Total C4's Ga so lin e L CO Co nv er si on
DeltaFCCYields,
wt.%
6.0
5.0
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-4.0Type 5 Type 6
Figure 2Impact of FCC Catalysts on Performance
Light Cycle Oil
Fuel Oil
CutterstockMarine
Diesel
Hydrocracker Hydrotreater
Jet
Kero
ULSD
LSD
Figure 3Outlets for FCC LCO
40 ISSUE No. 109 / 2011
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GRACE DAVISON CATALAGRAM 41
summarizes expectations forone such stream, marinediesel.
It is clear that FCC pretreatingplays an important part inreducing the sulfur content ofFCC products like gasoline
and LCO. ART has complet-ed many studies looking intothe effects of hydrotreating onFCC performance and thequality of the FCC products.The work demonstrates thatreducing the sulfur in FCCgasoline and LCO simplyrequires a reduction in thesulfur of the FCC feed byincreasing the severity of thepretreater. Figure 5 shows
the relationship between FCCfeed sulfur and the resultingsulfur of the FCC gasoline.This data was generatedusing a variety of FCC feedsthat had been hydrotreatedover several types of cata-lysts and catalyst systems.
As can be seen in the chart,there is a good correlationbetween FCC feed sulfur andthe corresponding FCC gaso-line sulfur. In this case, the
sulfur content in the FCCgasoline is roughly 100 timesless than the sulfur in thefeed to the FCC.
As might be expected, a simi-lar relationship exists betweenthe sulfur in the FCC LCOand the FCC feed sulfur. Anexample of this relationship isshown in Figure 6. This chartshows that the LCO sulfur is
roughly the same as the FCCfeed sulfur. These rules ofthumb are helpful when tryingto estimate the impact of achange in the FCC pretreaterand its effect on the FCCproduct sulfur levels.
Emission Control Areas (ECA)*
1.5 wt.%1.00 wt.% 0.10 wt.%
Sulfur Limit
4.5 wt.% 3.50 wt.% 0.50 wt.%
Global** For all limits, abatement technology (such as gas exhaust
scrubbing) is allowed as an alternative to using compliant fuel
2010 2012 2015 2018 2020 2025
Figure 4Proposed Sulfur Limits for Marine Diesel1
FCCGasolineSulfur,ppm
100,000
10,000
1,000
100
110 100 1000 10,000 100,000
FCC Feed Sulfur, ppm
Figure 5
Relationship Between FCC Gasoline Sulfurand FCC Feed Sulfur
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GRACE DAVISON CATALAGRAM 43
RatioofGasolineYieldto
LCO
Yield
2.8
2.7
2.6
2.4
2.3
2.2
2.1
0.80
2.0
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Nitroge
norPNA
Content(Prod/Feed)
1.9
1.8
2.5
Increasing Pretreater Severity
PNA
Nitrogen
Figure 8FCC Conversion Affects Gasoline and LCO Yields
Co
nversion,wt.%
73
72
71
LCOYield,
wt.%
70
69
24.0
23.6
23.2
22.8
22.4
LCO Yield
Conversion
Increasing % CoMo in Hydrotreater
Figure 9Pretreat Catalyst System Shifts FCC Yields
and the LCO yield decreases.Can this effect be mitigatedsomewhat by the properchoice of catalyst system inthe pretreater?
Another study was completedwhich investigated the
impacts of the pretreater cata-lyst system on FCC perform-ance. A range of catalystsystems were investigatedranging from 100% NiMo to asystem which was predomi-nantly CoMo catalyst. Figure9 compares the gasoline andLCO yields as a function ofthe catalyst system at con-stant pretreater severity. Thedata indicate that adjusting
the catalyst system doesresult in a shift in the FCCproduct yields. In this exam-ple, increasing the amount ofCoMo catalyst tends to resultin higher LCO yields and cor-respondingly lower gasolineyield. The data also suggeststhat there is an optimum cata-lyst system which can resultin a maximum LCO yield.
As expected, the quality of
the FCC products is alsoimpacted by the catalyst sys-tem. Figure 10 shows theFCC gasoline and LCO prod-uct sulfur observed in thesame study. As mentionedpreviously, there is a goodcorrelation between FCC feedsulfur and the FCC productsulfur.
This same work also looked
at the sulfur speciation for theFCC gasoline and LCO prod-ucts. This is useful informa-tion if the LCO issubsequently fed to ahydrotreater. Figure 11 com-pares the yield of LCO andthe amount of substituteddibenzothiophenes (hard sul-
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fur) remaining in the LCO asa function of the pretreatercatalyst system. The totalsulfur in the LCO decreasesat a significantly faster ratethan the hard sulfur concen-tration, but the amount ofhard sulfur as a fraction of the
total sulfur decreases at aneven faster rate. Decreasingthe total LCO sulfur by 25%lowers the hard sulfur con-centration by over 35%. Italso shows that as LCO sulfurdecreases, the yields of LCOcan shift assuming constantFCC operation. Simply cut-ting the LCO sulfur in halfwith additional pretreaterseverity can decreases the
quantity of LCO by almostone percent in this case.Again, the data suggeststhere may be an optimum cat-alyst system which can pro-vide the right balancebetween LCO yield and LCOsulfur content.
The LCO API gravity was alsoestimated from correlationsusing FCC feed gravity andFCC conversion since not
enough LCO product is pro-duced to measure density.The LCO API gravity gives arough indication of the aro-matic content and can also beuseful for estimating hydrogenconsumption if the LCO isbeing sent to a hydrotreatingor hydrocracking operation.Figure 12 shows some gener-al trends in LCO gravity as afunction of FCC conversion
and FCC feed API. There isa strong correlation betweenLCO API and the FCC severi-ty. As FCC conversionincreases to produce moregasoline, there is a negativeimpact on the LCO API indi-cating the LCO is becomingmore aromatic. By increasing
FCC Feed Sulfur, ppm
LCO
Sulfur,ppm
1,000 1,500 2,000 2,500 3,000 3,500 4,000
100
90
80
70
60
50
40
30
20
10
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
Gasoline
LCO
FCCGasolineSulfur,pp
m
Figure 10FCC Gasoline and LCO Sulfur Trends withFCC Feed Sulfur
Sulfur,wppm
8,000
7,000
6,000
5,000
4,000
3,000
2,000
24.0
1,000
0
23.8
23.5
23.3
23.0
22.8
22.5
22.3
22.0
LCOYield,wt.%
Hard S To tal S L CO Yi el d
Increasing % CoMo in Hydrotreater
Figure 11Impact of Pretreater Catalyst on LCO Yield andSulfur Species
44 ISSUE No. 109 / 2011
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GRACE DAVISON CATALAGRAM 45
pretreater severity, the qualityof the feed to the FCCimproves (API gravity increas-es) and at constant FCC con-version levels on the chart, itis apparent that the LCO APIincreases along with FCCfeed API, indicating that a bet-
ter quality LCO can be pro-duced.
Directionally decreasing theFCC to increase LCO produc-tion can increase the LCO
API by as much as 5 num-bers. This indicates there isan interesting interactionbetween the FCC pretreateroperation and the quality ofthe FCC LCO. Increasing the
severity of the pretreater willincrease the FCC feed APIand decrease the FCC feedsulfur and nitrogen. This canresult in a higher quality LCOin terms of lower sulfur andhigher API (higher cetane),but as alluded to earlier, thisrequires between 200-400SCFB higher hydrogen con-sumption at the pretreater.The higher cost may be justi-fied depending upon the mar-
gin of the finished productthat contains the LCO.
These correlations were alsoused to assess the productquality in terms of aromaticsor API in the study above. Asa general rule when the FCCfeed sulfur is decreased thereis a corresponding decreasein LCO yield and a decreasein LCO API gravity. However,
having to operate the pre-treater at higher temperaturesin order to lower the sulfurand improve the FCC feed
API is not the only solution toimproving product properties.Figure 13 compares severalpretreater catalyst systems,and shows how an optimized
FCC Conversion, wt.%
DeltaFCC
LCO
AP
IGravity
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
55 60 65 70 75 80 85
-8.0
-10.0
Feed API = 21.17
Feed API = 22.89
Feed API = 23.86
Figure 12Impact of Pretreatment on FCC LCO API
LC
O
APIGravity
24.025.5
24.5
25.0
LCO Yield
23.0
22.0
LCOAPI
LCOYield
,wt.%
Increasing % CoMo in Hydrotreater
Figure 13LCO Sulfur and Gravity Comparison
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GRACE DAVISON CATALAGRAM 47
In addition, the operation ofthe FCC changes the LCOyield and quality. This indi-cates that re-optimization ofboth the FCC and pretreateroperation is required toensure high yields of LCOand an overall profitable FCC
yield slate.
Different pretreat catalyst sys-tems can result in higher FCCbottoms yields if the FCC isnot re-optimized as it shiftsfrom maximum conversion tomaximum LCO operations.Figure 16 is an example ofcomparing the LCO yield gen-erated from two different FCCcatalysts processing the same
FCC feedstock. SwitchingFCC catalyst from A to B pro-vides several percent higherLCO yield at the same FCCfeed quality. This provides ameans to offset higher bot-toms yield which may occurfrom changes in the operationof the upstream pretreater tofocus on increasing LCOyields. Hu et.al. showed thatGrace Davisons MIDAS cat-alysts and Olefins Ultra ZSM-
5 technologies are aprofitable approach to mini-mize bottoms yield duringmaximum LCO operation.9
Conclusion
If the refiners objective is tomaximize the distillate pool itis important to understand thekey relationships betweenFCC pretreat and FCCU
operations and their corre-sponding catalyst systems.Both processes must be re-optimized as the refinermoves from gasoline to distil-late production to ensuremaximum profitability. All ofthe combinations presentedshow the need for refiners to
FCC Feed Sulfur, wppm
IncreasingLCOYield,wt.%
19
18
17
16
15
14
13
0 200 400 600 800 1000 1200 1400
FCC A
FCC B
Figure 16Changing FCC Catalyst
follow an integrated approachto managing the catalysts andoperation of the FCC pre-treater and FCC units. BothFCC and hydroprocessing
unit operations can be contin-uously optimized throughoutthe course of the hydrotreaterrun, to significantly increaserefiner revenue.
Results from a variety of ACEstudies using many differentfeeds and a variety of FCCpretreat catalyst systems indi-cate that the amount of sulfurin the FCC products is dictat-ed primarily by the FCC feedsulfur. Furthermore, forhydrotreated FCC feeds, thedistribution of sulfur in FCCproducts is independent ofthe type of FCC pretreat cata-lyst system employed anddepends solely upon theamount of sulfur in the FCC
feed. This work demonstratesthat the ability to make amajor impact on FCC yields isstrongly influenced by thetype of FCC pretreater cata-
lyst system used in conjunc-tion with the appropriate FCCcatalyst. Simply making achange to one operation with-out consideration for the othercan result in unexpectedresults and limited flexibility toproduce the fuels needed fordownstream blending or use.
Both the hydrotreating cata-lyst system and the operatingstrategy for the pretreater arecritical to providing the high-est quality feed for the FCC.Driving the hydrotreater toremove nitrogen and PNA'simproves FCC product valuewhen targeting gasoline pro-duction, but this needs to bebalanced against the
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increased costs of higherhydrogen consumption andshorter cycle length that resultfrom this mode of operation.Use of tailored ApART cata-lyst systems can optimize theFCC in order to produce notonly high quality feeds to the
FCC but also low sulfur prod-ucts resulting in less impacton downstream hydrotreating.This tailoring can also bebeneficial if the FCC prod-ucts are used directly withouthydrotreating, as they can bedriven towards lower sulfurand higher gravity productsallowing the refiner to beable to blend these fuelsdirectly. This creates a fuel
pool that can also have high-er cetane values due to thehigher gravity.
The complex relationshipbetween the FCC pretreaterand the FCCU underscoresthe importance of workingwith a catalyst technologysupplier that has the capabili-ties to understand the inter-play between the
hydrotreating performance ofthe FCC pretreater and theperformance, yield structureand product sulfur distribu-tions of the FCC. ART, andthrough its relationship withGrace Davison RefiningTechnologies, offers just such
capabilities and delivers themthrough tailored ApART cata-lyst systems to meet the refin-ers specific FCC feed slateneeds and FCC pretreat oper-ation constraints.
References
1. IFQA Handbook, 2010 edition, pp 106
2. Wollaston, E. G., Forsythe, W. L., and
Vasalos, I. A., Oil & Gas J., August 2, 1971,pp. 6