-
Dr.GirishK.ChitnisMr.RonD.McGihonMr.Aneesh
PrasadMr.ChristopherM.Dean
ExxonMobilResearchand
EngineeringCompany(EMRE)
Sulfuric Acid Alkylation Technology
RTM,India2009
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2Overview{{
GrowingImportanceofAlkylationGrowingImportanceofAlkylation
{{ BasicChemistryandProcessFlowBasicChemistryandProcessFlow
{{
CriticalAlkylationUnitDesignConsiderationsCriticalAlkylationUnitDesignConsiderations
Reactor/SettlerDesign ReactorCoolingEfficiency
ReactorProductTreating IsobutaneAvailability
DesignandOperatingExperience
{{ SummarySummary
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3Installed Capacity - History of Alkylation
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1,800,000
1940 1950 1960 1970 1980 1990 2000
TotalSulfuricHF
A radical change from 1990 onA radical change from 1990
onSulfuric Acid Sulfuric Acid AlkylationAlkylation the current
technology of choicethe current technology of choice
b
p
d
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4Comparing cost of technologies in equal basis...
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5Growing Importance of Alkylation
{{ Increased Incentive with Expanded Refining and Increased
Incentive with Expanded Refining and Cracking Capacity and Entry
into Global Market Cracking Capacity and Entry into Global Market
placeplacez FCC and Coker Expansionsz Export Refineries
{{ Reduced Emissions Gasoline Regulations Favor Reduced
Emissions Gasoline Regulations Favor Alkylate BlendstockAlkylate
Blendstockz No Olefinsz No Aromaticsz Low Sulfurz Low RVPz High
Octanez Good Distillation Characteristics
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6Alkylation Chemistry Simplified Primary Alkylation
Reactions
C3= + iC4
C5= + iC4
RONRON MONMON RVPRVP, psi, psi889688
879487
3.82.64.0
C4= + iC4iC7iC8iC9
{ Secondary Reactions Produce Wide Spectrum of Compoundsz
Polymerizationz Hydrogen Transferz Disproportionationz Cracking
{ Esters Produced as Reaction Intermediates May be Present
{ Feed Impurities Form Acid Soluble Compounds
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7Simplified Flow DiagramExxonMobil Stirred, Autorefrigerated
Alkylation ProcessExxonMobil Stirred, Autorefrigerated Alkylation
Process
Compression System
CW
Reactor System
Effluent Wash X 2
CW
STMSTM
CW
CW
Fractionation System
Acid
Refrigeration
Caustic Water
Olefin Feed
Isobutane
Recycle Isobutane
Propane
Butane
Alkylate
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8Overview of Alkylation Process Variables
VariableVariable Typical RangeTypical Range Effect On
ProcessEffect On Process
Isobutane Concentration (Average) High Isobutane Concentration
Preferred
This Range Considered Near Optimum
Low Space Velocity Desired
50 - 70 LV%
Olefin Space Velocity 0.1 - 0.3 V/H/V
Lower Temperature DesiredTemperature (Average) 40 - 50F
Maintain Greater Than 50%Percent Acid-In-Emulsion 50 - 60
LV%
Spent Acid Strength (SAS) 90 - 92 WT% H2SO4
Good Mixing EssentialMixing Moderate - Intense
Feed Point Conditions are ImportantOlefin Injection
ExxonMobil Selects Design Conditions for Economic Balance of
Process Performance Versus Capital and Operating Costs
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9Distinguishing Process Features Reactor Capacity
Olefin FeedPlusIsobutaneRecycle
HydrocarbonAcid
ToDeisobutanizer
KO Drum
Refrigerant
Settler Hydrocarbon Vaporsto RefrigerationCompressor
M M
M M M M M
Refrigerant
Settler
Olefin FeedPlusIsobutaneRecycle
HydrocarbonAcid
Reactor
Recycle Acid
ToDeisobutanizer
Hydrocarbon Vaporsto Refrigeration Compressor
Indirect Refrigeration System
Indirect RefrigerationIndirect Refrigeration SystemSystem
ExxonMobil Autorefrigeration System
ExxonMobil Autorefrigeration ExxonMobil Autorefrigeration
SystemSystem
{ MultipleReactorsz Upto2000BPSDAlkylateEach
{ HighSpaceVelocity{ SignificantEsterFormation
z RequiresExpensiveAcidWashz AcidWashClaimedEffectiveforDIB
Corrosion/FoulingMitigation
{ SingleReactorz Upto9000BPSDAlkylateEach
{ LowSpaceVelocity{ NegligibleEsterFormation
z SimpleRx.ProductTreatingz NoDIBOverheadCorrosionorDIB
ReboilerFouling
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10
Distinguishing Process Features Reactor Cooling Methods
{ DirectiC4Vaporization{ ZeroDegreeTemperature
Approach{ SimpleInternals{ LowPressureReactor{
LowMixingPower
z SufficientforEmulsification
Hydrocarbon Vaporsto Refrigeration Compressor
M M M M M
Refrigerant
Settler
Olefin FeedPlusIsobutaneRecycle
HydrocarbonAcid
Reactor
Recycle Acid
ToDeisobutanizer
Hydrocarbon Vaporsto RefrigerationCompressor
Settler
ReactorRecycle Acid
HydrocarbonAcid
RefrigerantToDeisobutanizer
KO Drum
M
Olefin FeedPlusIsobutaneRecycle
Indirect Refrigeration System
Indirect RefrigerationIndirect Refrigeration SystemSystem
ExxonMobil Autorefrigeration System
ExxonMobil Autorefrigeration ExxonMobil Autorefrigeration
SystemSystem
{ NoiC4Vaporization{ FiniteDeltaTemperatureRequired{
LargeNo.ofTubesforIndirectCooling{ HigherPressureReactor{
HigherMixingPower
z NeededforCirculationandHeatTransfer
ExxonMobil Reactor is Simpler and More Energy Efficient
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11
Distinguishing Process Features Reactor Product Treating
{{ ExxonMobil Treating System Less ComplexExxonMobil Treating
System Less Complexz Simple Settling Drums and Smaller Vessel
Sizesz No Stream Heating Required, Results in Lower Cooling Water
and Smaller DIB Condenser
{{ ExxonMobil Treating System Provides Low Risk of Serious
ConsequeExxonMobil Treating System Provides Low Risk of Serious
Consequence nce in Event of Acid Carryover Upsetin Event of Acid
Carryover Upset
ExxonMobil SystemExxonMobil SystemExxonMobil System Alternative
SystemAlternative SystemAlternative System
CausticWash
CausticWash
WaterWashWaterWash
Acid Wash(ElectrostaticPrecipitator)
Acid Wash(ElectrostaticPrecipitator)
AlkalineWater Wash
AlkalineWater Wash
ReactorProduct
ReactorProduct
85o F
10 wt %NaOH Fresh Acid
Fresh Water
To DIB To DIB
Fresh Waterplus
2 wt % NaOH
120o F
ExxonMobil Treating System is Simpler and Lower Cost
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12
Alkylation Plant Relative Investment Comparison
{{
ExxonMobilAutoExxonMobilAutorefrigerationProcessFeaturesReduceInvestmentrefrigerationProcessFeaturesReduceInvestmentz
FewerReactorandSettlerVesselsz
LessComplexReactorProductTreatingFacilitiesz
SmallerRefrigerationCompressor
ExxonMobilAutorefrigeration
IndirectRefrigeration
Reactor/Settler Base Higher
Reactor Product Treating Base Higher
Refrigeration Base Higher
Deisobutanizer and Debutanizer Base Base
Depropanizer Feed Treating Base Base
Depropanizer Base Base
Relative InvestmentRelative Investment
Equipment SectionEquipment Section
ExxonMobil Autorefrigeration Process Has Lower Plant
Investment
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13
Alkylation Commercial Experience ListCompany Location
NominalAlkylate
KBSD
StartUpYear
ExxonMobil Unit U.S. 30 1956
ExxonMobil Unit U.S. 30 1957
Licensed Unit U.S. 10 1958
ExxonMobil Unit Japan 2 1958
ExxonMobil Unit Aruba 4 1958
Licensed Unit Japan 4 1986
ExxonMobil Unit Japan 8 1988
ExxonMobil Unit Belgium 6 1991
ExxonMobil Unit France 6 1993
Licensed Unit U.S. 7 1994
Licensed Unit Thailand 7 Deferred
Licensed Unit Taiwan 14 2000
ExxonMobil Unit Australia 2 2001
Licensed Unit Russia 9 2005
LicensedUnit India 83KBSD 2009
LicensedUnit India 15KBSD 2012
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14
Independent Evaluation Sulfuric Acid Alkylation Plant
Economics*
{ ExxonMobilPlantInvestment7%LowerThanIndirectRefrigeration
{
ExxonMobilPlantUtilityCosts21%LowerThanIndirectRefrigeration
ExxonMobilExxonMobilAutorefrigerationAutorefrigeration
IndirectIndirectRefrigerationRefrigeration
43.5 47.0
7.1 9.0
Capital Investment (ISBL), M$
Utilities, M$/Yr**
References:Catalyst Consultants, Inc., Refinery Alkylation: An
Environmental, Technical, and Process Assessment, April, 1991,
pages 3.42 and 3.46.*Basis is 10 kBCD alkylate, 1991 basis updated
to 2000 U.S. Gulf Coast location, inside battery limits**Utilities
include power, cooling water, and steam
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15
Designing for Isobutane AvailabilityOption1BypassOlefins{
MinimumInvestment{ ReducedAlkylateMake Alkylation
UnitOlefin Feed Alkylate
Propane
Olefin Sales
n-Butane
Isobutane
Alkylation Unit
Olefin Feed Alkylate
Propane
n-Butane
S
p
l
i
t
t
e
r
Olefin Sales
Isobutane
Option2OlefinSplitter{ AlkylateAboveOption1{
IncreasedEnergyCosts{ IsobutyleneaHigher
PercentageofAlkylationUnitFeed
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16
Designing for Isobutane Availability
Option3EMOGASUnit{ LowerInvestmentandOperating
Costs{ DimerizeOlefinstoBalance
Isobutane{ OperateEMOGASReactorsto
ControlConversion{ GasolineProductionAboveOption2
Unreacted Olefins
Alkylation UnitOlefin Feed
EMOGAS
Alkylate
Propane
Poly Gasoline
n-Butane
Isobutane
Olefin Sales
Alkylation UnitOlefin Feed
Isobutane
n-Butane Isomerization
Alkylate
Propane
n-Butane
Option4
ButaneIsomerization
{ MaximizesAlkylateProduction{ HighestInvestmentCost
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17
SummarySummary
{{
ExxonMobilExxonMobilsProcessisaSignificantImprovementOvertheIndirectsProcessisaSignificantImprovementOvertheIndirectRefrigerationDesignRefrigerationDesign
{{
ExxonMobilExxonMobilsProcessConsumesLessUtilities(10sProcessConsumesLessUtilities(1020%less)20%less)z
LowerPowerUseinAutorefrigeratedSystemisSignificant
{{
ExxonMobilExxonMobilsProcessLeadstoLowerPlantInvestment(7%lower)sProcessLeadstoLowerPlantInvestment(7%lower)z
SmallerRefrigerationCompressorz SingleTrainReactorz
SimpleReactorDesign AmenabletoCompetitiveBiddingBased
onExxonMobilSpecificationsz LessCostlyTreatingFacilities
{{
ExxonMobilExxonMobilsProcessHasHighReliabilitysProcessHasHighReliabilityz
Mixersealsinvaporspace;replaceableduringoperation
{ ExxonMobilhasrecentlylicensed2Alkylation
unitsinIndia.Thefirst83kbsd
unithasstartedupandisoperatingwell.
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18
Thank You!
Sulfuric Acid Alkylation TechnologyOverviewInstalled Capacity -
History of AlkylationComparing cost of technologies in equal
basis...Growing Importance of AlkylationAlkylation Chemistry
SimplifiedSimplified Flow DiagramOverview of Alkylation Process
VariablesDistinguishing Process FeaturesReactor
CapacityDistinguishing Process FeaturesReactor Cooling
MethodsDistinguishing Process FeaturesReactor Product
TreatingAlkylation Plant Relative Investment ComparisonAlkylation
Commercial Experience ListIndependent Evaluation Sulfuric Acid
Alkylation Plant Economics*Designing for Isobutane
AvailabilityDesigning for Isobutane AvailabilitySummarySlide Number
18
