01 09_Gasoline_Upgrading( 2slide 1page)

7/27/2019 01 09_Gasoline_Upgrading( 2slide 1page)

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GasolineUpgrading:CatalyticReforming,Isomerization,&AlkylationChapters10&11


2/62

Light Naphtha

CrudeOil

Desalter

AtmosphericDistillation

VacuumDistillation

GasSeparation &

Stabilizer

SolventDeasphal-

ting

Coking

Visbreaking

FluidizedCatalyticCracking

Hydro-cracking

NaphthaReforming

Isom-erization

Sat GasPlant

Polymer-ization

Alkylation

NaphthaHydro-treating

Treating &Blending

Coke

Fuel Gas

LPG

AviationGasoline

AutomotiveGasoline

Solvents

Jet Fuels

Kerosene

Solvents

Heating Oils

Diesel

ResidualFuel Oils

Lubricant

Greases

Waxes

Asphalts

HeavyNaphtha

Kerosene

Distillate

AGO

LVGO

HVGO

VacuumResiduum

CatDistillates

Gas OilHydro-treating

DAO

Isomerate

Gas

AlkylFeed

Alkylate

PolymerizationNaphtha

Gases

Butanes

LPG

Reformate

Naphtha

Fuel OilBottoms

Distillates

DistillateHydro-treating

CatNaphtha

Cycle Oils

SDABottoms

CokerNaphtha

Heavy

CokerGasOil

Light CokerGas Oil

SulfurPlant

Sulfur

Naphtha

Fuel Oil

SolventDewaxing

Lube Oil

Waxes

2


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PurposeofGasolineFinishingProcesses

Feedstockssameboilingrangeasgasolineorslightlylower

Startwithlowoctanegasolineblendstocks

CatalyticReforming

Convertsnaphthenes to

aromatics

Produceshydrogen

Isomerization

Rearrangesstraightchainsto

branchedisomers

Verylittlechangeinboilingpoints

Increasemolecularsize

Alkylation

Useolefinsproducedinother

processes(primarilyFCCU)

3


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DependencyofOctaneonChemicalStructure

RON MON RON MON

Paraffins Naphthenes

nbutane 94 89.6 cyclopentane 100 84.9

isobutane 102 97.6 cyclohexane 82.5 77.2

npentane 62 62.6 mcyclopentane 91.3 80

ipentane 92 90.3 C7naphthenes 82 77

nhexane 24.8 26 C8naphthenes 55 50

C6monomethyls 76 73.9 C9naphthenes 35 30

2,2dimethylbutane 91.8 93.4

2,3dimethylbutane 105.8 94.3 Aromatics

nheptane 0 0 benzene 102.7 105

C7monomethyls 52 52 toluene 118 103.5

C7dimethyls 93.76 90 C8aromatics 112 105

2,2,3trimethylbutane 112.8 101.32 C9aromatics 110 101

noctane 15 20 C10aromatics 109 98

C8monomethyls 25 32.3 C11aromatics 105 94

C8dimethyls 69 74.5 C12aromatics 102 90

C8trimethyls 105 98.8

nnonane 20 20 Olefins/CyclicOlefinsC9monomethyls 15 22.3 nbutenes 98.7 82.1

C9

dimethyls 50 60 n

pentenes 90 77.2C9trimethyls 100 93 ipentenes 103 82

ndecane 30 30 cyclopentene 93.3 69.7

C10monomethyls 10 10 nhexenes 90 80

C10dimethyls 40 40 ihexenes 100 83

C10trimethyls 95 87 TotalC6cyclicolefins 95 80

nundecane 35 35 totalC7d 90 78

C11monomethyl 5 5 totalC8d 90 77

C11dimethyls 35 35

C11trimethyls 90 82 Oxygenates

ndodecane 40 40 MTBE 115.2 9 7.2

C12monomethyl 5 5 TAME 115 98

C12dimethyls 30 30 EtOH 108 92.9

C12trimethyls 85 80

4

DevelopmentofaDetailedGasolineCompositionBasedOctaneModel

PrasenjeetGhosh,KarltonJ.Hickey,andStephenB.Jaffe

Ind.Eng.Chem.Res. 2006,45,337345

60

40

20

0

20

40

60

80

100

120

140

0 50 100 150 200 250 300 350 400 450 500

BoilingPoint[F]

ResearchOctaneNumber

Aromatics

Naphthenes

Olefins&CyclicOlefins

Isoparaffins

NormalParaffins


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U.S.RefineryImplementation

5

Top 20 Atmospheric Distillation Capacity


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Light Naphtha

CrudeOil

Desalter


VacuumDistillation

GasSeparation &

Stabilizer

SolventDeasphal-

ting

Coking

Visbreaking


Hydro-cracking

NaphthaReforming

Isom-erization

Sat GasPlant

Polymer-ization

Alkylation


Treating &Blending

Coke

Fuel Gas

LPG

AviationGasoline

AutomotiveGasoline

Solvents

Jet Fuels

Kerosene

Solvents

Heating Oils

Diesel

ResidualFuel Oils

Lubricant

Greases

Waxes

Asphalts

HeavyNaphtha

Kerosene

Distillate

AGO

LVGO

HVGO

VacuumResiduum

CatDistillates


DAO

Isomerate

Gas

AlkylFeed

Alkylate


Gases

Butanes

LPG

Reformate

Naphtha

Fuel OilBottoms

Distillates


CatNaphtha

Cycle Oils

SDABottoms

CokerNaphtha

Heavy

CokerGasOil

Light CokerGas Oil

SulfurPlant

Sulfur

Naphtha

Fuel Oil

SolventDewaxing

Lube Oil

Waxes

6


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NaphthaReforming

Almosteveryrefineryintheworldhasareformer

Purposetoenhancearomaticcontentofnaphtha

Feedstockstoaromaticscomplex

Improvetheoctaneratingforgasoline

Manydifferentcommercialcatalyticreformingprocesses Hydroforming

Platforming

Powerforming

Ultraforming

Thermoforcatalyticreforming

Primaryreactions Dehydrogenation naphthenes aromacs

Isomerization normalparaffins branchedisoparaffins

Hydrogenasbyproduct

Ultimatelyusedinhydrotreating

Catalyticreforming2ndtoFCCincommercialimportancetorefiners

Reformatedesirablecomponentforgasoline Highoctanenumber,lowvaporpressure,verylowsulfurlevels,&lowolefinsconcentration

USregulationsonlevelsofbenzene,aromatics,&olefins

Airqualityconcerns

7


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CharacteristicsofPetroleumProducts

8

Reforming:driveoffhydrogenforbettergasolinepropertiesw/ochangingsize


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CatalyticReformingTechnologies

9

Provider Features

Axens(1)

Catalystregeneratedinplaceatendofcycle.Operatesin

pressurerangeof170 350psig.

Axens(2)

AdvancedOctanizingprocess,usescontinuouscatalyst

regenerationallowing

pressures

as

low

as

50

psig.

UOP

CCRPlatformingprocess.Radialflowreactorsarrangedin

verticalstack.


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Feedstocks&Products

Hydrotreatedheavynaphthafeedstock

Lightstraightrunnaphthatendstocracktobutanes&lighter

Gasoilstreamstendtohydrocrack&depositcokeonthereforming

catalyst

Catalystisnoblemetal(e.g.platinum) verysensitivetosulfur&nitrogen

Feedstockshydrotreatedforsulfur&nitrogenremoval

Controlofchloride&wateralsoimportant

Severity

Highseverityusedtomaximizearomatics

SenttoBTXseparationforaromaticfeedstocks

Lowseverityusedforgasolineblendstocks

Producesthemajorityofthehydrogenusedforhydrotreating

10


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ReformingChemistry

Usesasolidcatalysttoconvertnaphthenestothecorrespondingaromatics&isomerizeparaffinicstructurestoisomericforms

Bothreactionsleadtoamarkedincreaseinoctanenumber

Bothreactionsleadtovolumeshrinkage

CorrelationspermittheuseofaPONAanalysisofthefeedforpredictionofyieldandqualityoftheproduct

OriginallyfeedqualitiesmeasuredintermsofWatson"K"Factor aroughindicationof

amountofparaffins

Aromaticslargelyuntouchedbyreactions

11


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ReformingChemistry

12

CH3 CH3

+ 3 H2

Dehydrogenation

+ H2

Dehydrocyclization

CH3

CH3

CH3

CH3

+ H2

Isomerization

CH3CH3

CH2

CH3CH3

HydrocrackingCH2CH3 CH3

+ H2 +


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UseofYieldCharts

Vol% Wt% Density

H2S H2Correction

Hydrogen Fig10.7

C1+C2 Fig10.6

C3 Ratio Fig10.6 Pure

C4sIC4

Fig10.541.5% Ratio Pure

NC4 58.5% Ratio Pure

C5+Gasoline Fig10.4 Ratio

Total 100%

13

Notes:

YaxisofFig10.4isC5+gasolineyield

TypicallyusetheWatsonKFactoroffeedinFig10.4.


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ReformerYieldExample

14

Example

Sulfur Waterdensity@60F= 8.33718 lb/gal

FeedInformation: AveBPT Specific API Watson Content 350.162 lb/bblF Gravity Gravity KFactor wt% H2Mol Wt= 2.02

297.4 0.7724 51.7 11.80 0.100 SulfurMol Wt= 32.064

scfper

mol

= 379.5

TargetRON: 99.0

ProductDistribution:Fraction bbl/day lb/hr lb/day vol% wt% API SpGr lb/bbl mol/hr scf/hr mol/day

Feed 40,000 450,763 10,818,310 51.7 0.7724 270.5

H2S 479 11,500 14 5,335 337

H2 15,228 365,477 7,539 2,860,840 180,929

C1+C2 12,153 291,678 2.70

C3 2,154 15,933 382,386 3.53 147.6 0.5070 177.5

Is obutane(IC4) 1,148 9,425 226,206 2.87 119.9 0.5629 197.1

nbutane(NC4) 1,618 13,784 330,821 4.04 110.8 0.5840 204.5

C5+ 31,831 383,760 9,210,243 79.58 39.7 0.8263 289.4

Total 3 6,7 50 4 50 ,7 63 1 0,8 18 ,3 10

UncorrectedYieldsSulfur 451 10,818 14 337

H2(uncorrected) 15,257 366,158 3.38 7,553 2,866,174 181,266

C4(Total) 6.91

YieldsonOilFeed StandardDensities

ProductYieldsfromReformer


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GasolineYieldvs.ReformateOctane

15

Notes:

YaxisisC5+gasoline

yield

Typicallyusethe

WatsonKFactorof

feedinFig10.4.


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LightEndsProduction

16

Notes:

TypicalC4Split:

iC4=41.5%,nC4=58.5%


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CombinedProductionTrends

17

Combination Yields from Figures 10.4 to 10.7

0

1

2

3

4

5

6

7

8

9

10

89 90 91 92 93 94 95 96 97 98 99 100 101

Reformate RON Clear

%L

ight

EndsYield

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

Vol%Ga

solineYield

Feedstock Watson K Factor is 11.8

Gasoline

Vol% C4s

Wt% C3

Wt% C1+C2

Wt% H2


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BoilingPointRangesforProducts

18

Kaes's Example Naptha Hydrotreating & Reforming Problem

-

500

1,000

1,500

2,000

2,500

0 100 200 300 400 500 600

BPT [F]

Incrementa

lYield[bpd]

84-reformate

77-Ovhd liquids

75-Offgas

1-Sour.naphtha

9,999 bpd Sour Naptha Feed

8,314 bpd Reformate


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EffectsofProcessVariables

Primarycontrolforchangingconditionsorqualitiesisreactortemperature

Normallyabout950Fatreactorinlet

Mayberaisedfordecliningcatalystactivityortocompensateforlowerqualityfeedstock

Higherreactortemperatureincreasesoctaneratingbutreducesyieldandrunlength

Designconsiderationsforimprovementinqualitywillincludepressure,recycleratio,reactorresidencetime,&catalystactivity

Lowreactorpressure increasesyield&octanebutincreasescokemake Increasedhydrogenpartialpressure duetohydrogenrecycle(hydrogentohydrocarbon

ratio)suppressescokeformation,hydrogenyield&octanegain,butpromotes

hydrocracking

Lowspacevelocityfavorsaromaticsformationbutalsopromotescrackingbyoperatingclosertoequilibriumconditions

Higheractivitycatalystscostmorebutincreasesrunlengthsand/oryields

19


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20

Reaction Pressure Temperature

Isomerizationofnaphthenes Indeterminate Indeterminate

Dehydrocyclizationofparaffins

tonaphthenesLowpressure Hightemperature

Dehydrogenationof

naphthenestoaromatics

Lowpressure Hightemperature

Isomerizationofnormal

paraffinstoisoparaffins

Slight

dependenceSlightdependence

Hydrocracking Highpressure Hightemperature


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SpecificCatalyticReformingProcesses

Hydroforming

Earlycyclicprocessusedtoproducetoluenefor

TNTduringWorldWarII

Molybdenumoxideonaluminacatalyst

Rapidcokingofthecatalyst,requiringacyclic

regenerationofreactorsabouteveryfourhours

Timingmechanismusedforlawnsprinklersystems

usedtoswitchfromreformingtoregeneration

service

Reactorsystemincludedoneextra"swing"reactor

o Facilitateperiodicremoval&regenerationof

areactor

UOPSemiRegenerativePlatforming

Lowplatinum

Regenerationonceayear

Madenaphthaoctaneimprovementaccessibleto

allrefiners

UOPContinuousRegenerationofReformingCatalyst

Movingbedprocess

Continuouslyregeneratingaportionofamoving

bedofcatalysttoremovecoke&sustainactivity

Operatingpressuresloweredto50psig

Threereactorsstackedoneontopoftheother

Gravityflowofthecatalystfromtoptobottom

Reactantspassradiallythroughthecatalysttothe

innerconduitandthentothenextbed

Modeofregenerationisproprietary probably

employsairoroxygenburningofthecoke

followedbyreduction&acidification

21


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UOPPlatforming

22

RefiningOverview PetroleumProcesses&Products,

byFreemanSelf,EdEkholm,&KeithBowers,AIChECDROM,2000


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UOPsCCRPlatformingTM Process

23

http://www.uop.com/objects/CCR%20Platforming.pdf


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ReformerInstalledCost

Includes

ISBLfacilitiestoproduce102RON

reformatefromsulfurfreeHSRnaphtha

Productdebutanizer

Allnecessarycontrollers&instrumentation

AllISBLfacilities

Heatexchangetoacceptfeed&release

productsatambienttemperature

Excludes

Coolingwater,steam&powersupply

Feed&productstorage

Initialcatalystcharge

Royalty

Feedfractionationordesulfurization

24

PetroleumRefiningTechnology&Economics,5th ed.

Gary,Handwerk,&Kaiser

CRCPress,2007


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Light Naphtha

CrudeOil

Desalter


VacuumDistillation

GasSeparation &

Stabilizer

SolventDeasphal-

ting

Coking

Visbreaking

Fluidized

CatalyticCracking

Hydro-cracking

NaphthaReforming

Isom-erization

Sat GasPlant

Polymer-ization

Alkylation


Treating &Blending

Coke

Fuel Gas

LPG

AviationGasolineAutomotive

Gasoline

Solvents

Jet Fuels

Kerosene

Solvents

Heating Oils

Diesel

ResidualFuel Oils

Lubricant

Greases

Waxes

Asphalts

HeavyNaphtha

Kerosene

Distillate

AGO

LVGO

HVGO

VacuumResiduum

CatDistillates

Gas Oil

Hydro-treating

DAO

Isomerate

Gas

AlkylFeed

Alkylate


Gases

Butanes

LPG

Reformate

Naphtha

Fuel Oil

Bottoms

Distillates


CatNaphtha

Cycle Oils

SDABottoms

CokerNaphtha

HeavyCoker

GasOil

Light CokerGas Oil

SulfurPlant

Sulfur

Naphtha

Fuel Oil

SolventDewaxing

Lube Oil

Waxes

25


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C4&C5/C6Isomerization

C4isomerization

ConvertnC4 toiC4

iC4 moredesirableasalkylationfeedstock

C5/C6Isomerization

Improvetheoctaneratingofstraightrungasoline

Nparaffinsisomerizedtobranchedisoparaffins

WillalsoconvertanynC4 toiC4

HighRVP(about17psi) limitsitsuseingasolinepool

26


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27

Isomerization:rearrangemoleculesforbettergasolinepropertiesw/ochangingsize


28/62

IsomerizationTechnologies

28

Provider Features

AxensEither

once

through

or

Ipsorb

Isom

with

normal

paraffinrecycletoextinction.

CDTECH ISOMPLUSzeolitebasedcatalyst.

UOP(1)

ParIsomprocessuseshighperformancenonchlorided

aluminacatalysts

UOP(2)

HOT(hydrogenoncethrough)Penexprocess

eliminatesneed

of

recycle

gas

compressor.

Fixed

bed

usinghighactivitychloridepromotedcatalyst.

UOP(3)

HOT(hydrogenoncethrough)Butamerprocess

eliminatesneedofrecyclegascompressor.Twoseries

reactorsprovidehighonstreamefficiency.


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HistoryofIsomerization

AviationgasolineforWorldWarII

Butaneisomerizationwasdevelopedtocreatetheneededisobutanefeedstock

Aluminumchloridecatalyst

Manyoftheseunitswereshutdownafterthewar

TetraEthylLeadPhaseOutin1970s

StraightRunGasoline(SRG)reliedonTELforoctaneimprovement

ResearchOctaneNumber(RON)ofonly70

SRGmostlyparaffinicpentanes&hexaneswithsomeheptanesandoctanes

Isomerizationcouldprovideneededoctaneboost

EquivalentIsoparaffinshavehigherRON

29


30/62

C5/C6IsomerizationProcesses

Vaporphaseprocess

Hydrogenusedtosuppressdehydrogenation&coking

Highyields&highselectivitytohighoctaneisomericforms

Providesmoderate

(but

important)

contribution

tothe

gasoline

pool

Catalysttypes

Chloridealuminacatalyst

Organicchloridedepositedonactivemetalsites

o Hightemperaturetreatmentwithcarbontetrachloride

Chloridessensitivetomoisture dryingoffeed&hydrogenmakeupessential

Acidiczeolitewithnoblemetalcatalyst

Platinumcatalyst

Doesnotrequireactivationbyhydrogenchloride

30


31/62

C5/C6IsomerizationProcesses

Pros

ReformingconditionsnotappropriatefortheparaffiniccomponentsinSRG

Essentiallyzerobenzene,aromatics,&olefins

Verylowsulfurlevels

Cons

Highvaporpressure

Moderateoctanelevels (R+M)/2only85

31


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C5/C6Isomerization Feedstocks &Products

Lightestnaphthafeedstock(SRG)withpentanes,hexanes,&smallamountsof

heptanes

Feedoftendebutanized

Debutanized StraightRun

Sulfur&nitrogenmustberemovedsincecatalystsemployanacidsiteforactivity

Merox

Claytreating

Hydrotreating

CommonforStraightRunGasoline&Naphthatobehydrotreated asone

stream&thenseparated

Products

Isoparaffins &cycloparaffins

Smallamountsoflightgassesfrom

hydrocracking

Unconvertedfeedstock

Increasedseverityincreasesoctanebutalsoincreasesyieldoflightends

Yieldsdependonfeedstock

characteristics&productoctane

Poorqualityfeedsmightyield85%or

lessliquidproduct

Goodfeedsmightyield97%liquid

product

32


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IsomerizationChemistry

Primaryreactionistoconvertnormalparaffinstoisomericparaffins

Olefinsmayisomerizeandshiftthepositionofthedoublebond

1butenecoluldshifttoamixtureofcis2butene&trans2butene

Cycloparaffins(naphthenes)mayisomerize&breaktheringforminganolefin

Cyclobutanetobutene

33


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Lowtemperature,moderatehydrogenpartialpressure,lowspacevelocitypromotelongrunlengths

Isomerizationyieldscontrolledbychemicalequilibrium

Removingisoparaffins fromfeedstockcanshift thereactorequilibrium&

increasethefinalproductoctane

Temperatureprimaryprocesscontrolvariable

Highertemperaturesincreaseprocessingseverity(includinghydrocracking)

Otherprocessvariables Higherpressuresincreasecatalystlifebutincreasesundesirablehydrocracking

reactions

Increasedhydrogenpartialpressurepromoteshydrocrackingbutprolongs

catalystlife

Spacevelocitybalancedagainstcapitalcost,temperature,runlength&yields

Contaminantsreducecatalystlife

34


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ProcessImprovements

Numberofcombinationsoffractionationandisomerization

RemovingisopentanefromfeedincreasestheproductsRONto84

Additionofadepentanizeronproductstreamrecycleofnpentanerecycleincreases

productsRONto86

SeparationusingmolecularsievesincreasestheproductsRONto89

UOPcombinesPenexwithMolex

Separationcarriedoutentirelyinvaporphase norefluxutilitiesbutcyclicoperation

TotalrecyclewithadeisohexanizerincreasestheproductsRONto89

Suitableforblendingintopremiumatnooctanepenalty

35


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IsomerizationOptions

36

http://www.uop.com/processingsolutions/refining/gasoline/#naphthaisomerization

UOPPenexTM HydrocarbonOnceThrough

Limitedbyequilibrium

8084

RONC

Isomerization/DIH Recyclesunconvertedlowoctaneiosemrs

8789RONC

DIP/Isomeriaztion/SuperDIH

9093RONC


37/62

Isomerization InstalledCost

Includes

Dryingoffeed &hydrogenmakeup

Completepreheat,reaction,&H2

circulationfacilities

Productstabilization

Heatexchangetocoolproductsto

ambienttemperature

Allnecessarycontrollers&

instrumentation

Paidroyalty

Excludes

Hydrogensource

Feeddesulfurization


Feed&productstorage

Initialcatalystcharge

37



CRCPress,2007


38/62

Light Naphtha

CrudeOil

Desalter


VacuumDistillation

GasSeparation &

Stabilizer

SolventDeasphal-

ting

Coking

Visbreaking


Hydro-cracking

NaphthaReforming

Isom-erization

Sat GasPlant

Polymer-ization

Alkylation


Treating &Blending

Coke

Fuel Gas

LPG

Aviation

GasolineAutomotive

Gasoline

Solvents

Jet Fuels

Kerosene

Solvents

Heating Oils

Diesel

ResidualFuel Oils

Lubricant

Greases

Waxes

Asphalts

HeavyNaphtha

Kerosene

Distillate

AGO

LVGO

HVGO

VacuumResiduum

Cat

Distillates


DAO

Isomerate

Gas

AlkylFeed

Alkylate


Gases

Butanes

LPG

Reformate

Naphtha

Fuel OilBottoms

Distillates


CatNaphtha

Cycle Oils

SDABottoms

CokerNaphtha

HeavyCoker

GasOil

Light CokerGas Oil

SulfurPlant

Sulfur

Naphtha

Fuel Oil

SolventDewaxing

Lube Oil

Waxes

38


39/62

Alkylation&Polymerization

Processestomakegasolinecomponentsfrommaterialsthataretoolighttootherwisebeingasoline

Alkylation

Formalongerchainhighlybranchedisoparaffinbyreactinganalkylgroup(almostexclusivelyisobutane)withalightolefin(predominatelybutylene)

Produceshighoctanegasoline

Polymerization

Formationofveryshortchains

Productisnearlyallolefinic highresearchoctanebutmoderatemotoroctane

number

39


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40

Alkylation:combinesmallmoleculesforgasolinewithgoodproperties


41/62

AlkylationTechnologies

41

Provider Features

CDTECH(1) CDAlkyllowtemperaturesulfuricacidalkylation.

CDTECH

(2)

CDAlkylPluslowtemperaturesulfuricacidalkylation

coupled

with

olefin

pretreatment

step.

DuPont

UsesSTRATCOEffluentRefrigerationAlkylationprocess

usingsulfuricacid

LummusTechnology

AlkylCleanprocessusingsolidacidcatalyst.

Demonstrationunitonly.

RefiningHydrocarbon

TechnologiesLLC

RHTAlkylationprocessusessulfuricacid.Eductormixing

device.

ExxonMobilResearch&

Engineering Sulfuricacidalkylationusingautorefrigeratedreactor.

UOP(1) ModifiedHFAlkylationtoreduceaerosolformation.

UOP(2)

IndirectAlkylation(InAlk)usessolidcatalyst.Olefins

polymerize&highermolecularweightmaterial

hydrogenated.


42/62

OlefinAlkylation&Polymerization

1920s&1930sothermethodsusedtoimprovegasolineoctane

TetraEthylLeadinStraightRunGasoline

Thermalreformingofnaphtha

Thermalpolymerizationofolefinic lightendstohexenes,heptenes,&octenes

Inlate1930s&early1940s,alkylationofolefinswasdevelopedtoimprovetheoctaneofaviationgasoline

VladimirIpatieffhaddiscoveredaluminumchloridecatalysisin1932

FCCsignificantlyincreasedtheproductionoflightends

HighconcentrationoftheC3,C4,&C5isomers,botholefinic &paraffinic

Ledtodevelopmentofbothcatalyticpolymerization&alkylation

FollowingendoftheKoreanconflict(1953)refinersinvestigateduseoftheircatalyticpolymerizationandalkylationcapacityforproductionofhigheroctanemotorfuels

Chicken&egg increasingoctaneproductioncapacity&higherperformanceenginesinautomobilesledto

theoctaneraceinmid1950s

Bothpolymerization&alkylationwereadapted alkylationbecamethedominantprocess

Bythe1960s,polymerizationunitswerebeingphasedout&newplantsutilizedalkylationtechnology

42


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SulfuricAcidvs.HFAlkylation

SulfuricAcidAlkylation

Developedbyconsortiumofmajorrefiners&contractors

AngloIranianOil,HumbleOil&Refining,Shell

Development,StandardOilDevelopment,&the

TexasCompany

FirstunitatHumbleBaytownRefinery,1938

Manyalkylationplantswerebuiltatthesametime

asthecatalyticcrackingunits

OperatedduringWorldWarIIforaviation

gasolineproduction

Sulfuricacidalkylationrequiredaccesstoacidregenerationonalargescale

Mostlocatedondeepwaterforbargetransport

ofspentacidtoregenerationatacidplants&

returnoffreshacid

Economichandicapforinlandmidwestern

refineries

HFAcidAlkylation

DevelopedbyPhillipsPetroleum&UOP

HFcouldbereadilyregeneratedinalkylation

plantfacilities

Noneedtotransportcatalystinlargequantitiesforregeneration

43


44/62

Feedstocks &Products

Olefinicstreamfromthecatalyticcracker

Butyleneisthepreferredolefinsinceit

producesthehighestoctanenumber&

yields

isobutane&isopentanecanbereactedwiththeolefin

Isopentanenotusuallyusedsinceitisa

goodgasolineblendstock

Highoctanenumber&lowvapor

pressure

Catalyticcrackerfeedcontainssignificantsulfur

Treatingunitoftenprecedesalkylation

unit

Alkylatedesirablecomponentforhighperformanceautomotivefuels

Veryhighoctaneindex(R+M)/2of95

Lowvaporpressure

Vaporpressureisadjustedforfinal

boilingpoint

IBPadjustedforadditionofnormal

butane

Lowsulfur

levels

Essentiallynoolefins,benzeneor

aromatics

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C4Isomerization

UOPsButamerTM processisahighefficiency,costeffectivemeanstomeetisobutane

demandsbyisomerizingnC4toiC4

Equilibriumlimited

LowtemperaturefavorsiC4

Highactivitychloridedaluminacatalystsused

HighselectivitytoiC4byseparating&recyclingnC4toextinction

Oncethroughlowercapitalcost

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NButaneRecycledtoExtinction

OnceThroughNButaneConversion


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ProcessChemistry

Acidcatalyzedalkylationcombinesisoparaffins&olefinstoformalkylate,highlybranchedalkanes

Usuallyonlyisobutaneisused

Isopentaneisagoodgasolineblendstock

FriedelCraftsreaction Lewisacid(HForH2S04)promotes carboniumiononatertiaryisoparaffinthatrapidlyreactswithanydoublebonditencounters(propylene,butylenes,orpentylenes)

Thereactioncarriedoutintheliquidphasewithanacid/reactantemulsion

maintainedatmoderatetemperatures

Propylene,butylene,&pentenesareolefinsused butylenepreferred

Highoctaneisooctanealkylateproduced

Lowerreactantconsumption

Alkylationreactionshavecomplexmechanisms&mayproducemanydifferentvarieties

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ProcessChemistryExamples

Isobutylene&isobutaneform2,2,4trimethylpentane(isooctane)

Propylene&isobutaneform2,2dimethylpentaneasprimaryproductwith2,3dimethylpentane&2,4dimethylpentaneassecondaryproducts

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C CH2

CH3

CH3

+ H+ C

+CH3

CH3

CH3

C+

CH3

CH3

CH3 CH

CH3

CH3

CH3 + H+

C

CH3

CH3

CH3 CH CH3

CH3

CH2+


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OperatingVariables&TheirEffects

Capacityexpressedintermsofalkylateproduct,notfeedcapacity Mostimportantvariables

Typeofolefin

Propylene,butylene,

orpentene

Isobutane concentration isobutane:olefin ratio

Olefininjection&mixing

Reactiontemperature

Catalysttype&strength

Criticalmeasuresforsuccess

Alkylateoctanenumber

Volumeolefin&isobutane consumedpervolumealkylateproduced

Degreeofundesirablesidereactions

Acidconsumption

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TypeofOlefin

Butylenepreferred

Producesthehighestisooctanelevels

ResultingResearchOctaneNumbersof9395(withisobutane)

RONandMONareaboutequalforalkylation

Amountsofbutyleneconsumedperalkylateproducedisthelowest

Sidereactionsarelimited

Propyleneworse

Octanenumbersarelow(8992RON)

Propylene&acidconsumptionarehigh

Penteneresultsaremixed

Sidereactions

frequent

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Isobutaneconcentration

Excessisobutanerequired normalvolumeratioofisobutanetoolefininthefeedis610

Limitedisobutanesolubilityinacidphase

Olefinsneedtobesurroundedbyisobutaneexposedtoacid ifnot,olefinswillpolymerizeinsteadofalkylate

Newerplantshavemultiinjection&vigorousmixingsystems

Effectofisobutaneisexpressedintermsofconcentrationinthereactionzone

Isobutanetoolefinratiosmaintainedat10,000to1

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Isobutane/OlefinInjection&Mixing

Moreimportantinsulfuricacidsystems

Acidviscosityatoperatingtemperatures

Provideoptimalreactionconditionsfortheveryfastreaction

Injectolefinfeedstockinincrementalfashiontoincreaseisobutane/olefinratios

Newerplantsdesignedformultiinjectionlocationsintoanagitatedemulsionto

disperseolefinasrapidlyaspossible

Systemswithsinglepointinjectioncaneasilyhaveanoverloadofolefininthe

emulsion

Leadstolowerquality&higheracidconsumptionfromesterificationreactions

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ReactionConditions

Reactiontemperature

Mostnoticeablevariableinbothreactionsystems

Increasingtemperaturereducesoctane

number

HFsystemsrunat95F

Coolingwatersufficient

Sulfuricacidsystemsrunat45F

Refrigerationmayberequired

Oftenemployautorefrigerationofthe

reactantmasstoprovidecoolantfor

thereactors

Acidstrength

HFacidstrengthisnotanimportantvariableintherangeof80%to95%

Sulfuricacidstrengthissomewhata

functionofthediluent

Waterlowersacidactivity3to5times

asfastashydrocarbondiluents

Acidisconsidered"spent"ataround

88%sulfuricacid

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SulfuricAcidAlkylation

54




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TimeTankReactors

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Autorefrigerated ReactorSulfuricAcidAlkylation(EMRE)


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(EMRE)

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SulfuricAcidAlkylationTechnology

Dr.Girish K.Chitnis,Mr.RonD.McGihon,Mr.Aneesh PrasadandMr.ChristopherM.Dean

GrowingImportanceofAlkylationSeptember2009

http://www.exxonmobil.com/Apps/RefiningTechnologies/Files/Conference_2009_sulfuricalkylation_Sept.pdf

STRATCOContactor ReactorS lf i A id Alk l ti (D P t)


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SulfuricAcidAlkylation(DuPont)

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STRATCOAlkylationTechnologyImprovements

KevinBockwinkel

2007NPRAAnnualMeeting

http://www2.dupont.com/Sustainable_Solutions/en_US/assets/downloads/stratco/STRATCO_AlkylationTechnologyImprovements.pdf

HF Alk l ti S t


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HFAlkylationSystem

Differencestosulfuricacidsystems

Feeddriersessentialtominimizecatalystconsumption

WaterformsanazeotropewithHFleadingtoacidloss

HFstripperrequiredondepropanizeroverheadtocleanuppropaneforLPG

HFregeneratoroperatingonaslipstreamfromacidsettler

Manyacidsolubleorganiccompoundsdecomposebutsomemustberejectedasacidsolubleoil

Spentacidrequiresspecialneutralization

ConvertHFtocalciumfluoride&burnablewaste

Overallacidlossshouldbelessthanonepoundperbarrelofacidproduced

ElaborateHFventing,neutralization&recoverysystem

ConsideredbythepublictobeathreatintermsoflargereleasesofHF

NewdesignsminimizetheinventoryofHFintheunitfarbelowearlierdesigns

Riskisminimized,noteliminated

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UOP/Phillips Alkylation Process


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UOP/PhillipsAlkylationProcess

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http://www.uop.com/processingsolutions/refining/gasoline/#alkylation



CRCPress,2007

Phillips Alkylation Process


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PhillipsAlkylationProcess

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Component Olefin Feed SaturatedButanes Propane YieldMotor-Fuel

Butane YieldMotor-Fuel

Alylate Yield Acid OilsEthane 0.49 0.49

Propylene 21.04

Propane 17.42 0.30 18.77

Isobutane 191.81 13.48 0.34 3.13 0.19Butenes 169.10

n-Butane 63.17 10.11 63.35 9.93

Pentanes 4.90 0.42 3.67 1.65

Alkylate 390.17

Acid Oils 0.55

Total 467.93 24.31 19.60 70.15 401.94 0.55

Stream Totals 492.24 492.24

RVP [psi] 6.0

Specific Gravity 0.70

RON, clear 95.0

MON, clear 93.5

FBP [C] 195

FBP [F] 383

Alkylation Installed Cost


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AlkylationInstalledCost

Includes

Facilitiestoproducealkylate fromfeed

withiC4&C3toC5olefins

Allnecessarycontrollers&

instrumentation

AllISBLfacilities

Feedtreating(molecularsievetoremove

moisturefromfeed)

Excludes


Feed&productstorage

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CRCPress,2007

Gasoline Upgrading Process Comparisons


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GasolineUpgradingProcessComparisons

Pros

Reforming

Highoctane

LowRVP

Byproducthydrogen

Isomerization

BetteroctanethanLSR

Toolightforreforming

Lowaromatics&olefins

Verylowsulfurlevels

Alkylation

Goodoctane

LowRVP

Cons

Reforming

Higharomatics(benzene)

Isomerization

Octanestillrelativelylow

HighRVP

Alkylation

Requireslightends issueifno

FCCU

HFcommunityconcerns

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01 09_Gasoline_Upgrading( 2slide 1page)

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