OUT LINE
• Base Oil production • LOBS quality
• Basics of LOBS Manufacturing Technologies
• Details of LOBS Processing schemes
• Observations & Conclusions
LOBS Quality
Present LOBS quality fall under API Group I.
Spindle 150 N 500 N BS
Appearance B&C B&C B&C B&C
VI 98-100 100-101 95-97 95-97
Pour point C -6 -1 -1 -6
Color, ASTM 0.5 <1.0 <2.5 <3.5
Sulphur, wt% 0.8– 0.9 1.0-1.1 1.2-1.3 1.3-1.4
Saturates, wt%
NA @ 67 @ 65 NA
LOBS Quality
American Petroleum Institute (API) LOBS CategoriesAPI Sats Sulfur VI Typical Manufacturing ProcessI <90% >0.03% 80-119 Solvent ProcessingII >90% <0.03% 80-119 HydroprocessingIII >90% <0.03% 120+ Wax IsomerisationIV n.a n.a Polyalphaolefins (PAO)V All other Basestocks
LOBS Quality
• API specs are not regulatory as in case of automotive fuels, but are set by market & customer requirements.
• API specs are very broad.
• What level of API specs the LOBS need to comply with?
• A refiner may meet the bare minimum saturates as per Group II (90%) and yet may not meet market demand for 99% saturates.
LOBS Quality
• The refiner with this situation must address many questions.
• What are the target specs of each product?
• What are the various technology options available?
• Product slate (Grades of LOBS & whether wax is a product or not?)
• Integration of Lube block & Fuel block
• How doest it affect the over all profitability?
Base oil Manufacturing Technology
Crude SourceCrude Source
V.I. Upgrading
V.I. Upgrading FinishingFinishingDewaxingDewaxing Base OilBase Oil
Conventional Solvent Refining Solvent Dewaxing Low pressure Hydrotreating
Modern Hydrocracking CatalyticDewaxing Hydrofinishing
Alternate
Alternate
Hydrocracking
Solvent Refining/ Hydrotreating
Isodewaxing/MSDW
Isodewaxing/MSDW
Hydrofinishing
Hydrofinishing
Base oil Manufacturing Technology
Crude SourceCrude Source
Hydrocracking/Hydrotreating
Hydrocracking/Hydrotreating
Noble Metal HF
Noble Metal HFDewaxingDewaxing Base
OilBase Oil
Hydrocracking/Hydrotreating
• High Yield
• Feed Flexibility
• Satisfy Fuel & Lubes Demand
HCR/HDT boosts V.I. By converting low V.I. components to high V.I. base oils and also by cracking low V.I. components to lower boiling ranges----- Solvent refining simply removes low V.I. Aromatic components
Base oil Manufacturing Technology
Crude SourceCrude Source
Hydrocracking/Hydrotreating
Hydrocracking/Hydrotreating
Noble Metal HF
Noble Metal HFDewaxingDewaxing Base
OilBase Oil
Isodewaxing(IDW, CLG)/Mobil Selective Dewaxing (MSDW, EMRE)
• High V.I. Retention resulting in higher overall Yield for Lube train
• Ability to handle high wax feeds such as Slack wax.
IDW/MSDW reduces pour point primarily by Catalytic Wax Isomerization, giving higher overall product Yield and V.I. Than Solvent Dewaxing or conventional Catalytic Dewaxing.
ISODEWAXING
Isomerization With Minimum Branching Maintains V.I. and Lowers Pour Point
V.I Melting Point, oCN-Paraffin I-Paraffin N-Paraffin I-Paraffin
C20 174 164 36.6 -2.5 39.1
C30 156.5 143 66 8.6 57.4
Example of how isomerization can lower pour point, yet maintain high VIExample of how isomerization can lower pour point, yet maintain high VI
Comparison of Dewaxing ProcessesSolvent Dewaxing Catalytic Dewaxing IDW/MSDW
Wax removal
Product Pour Point
Yields
Dewaxed Product V.I.
By – Products
Operating costs
Physical – Wax Crystallization and filtration
-10 to –15 o C
Base Case
Base Case
Slack wax
Base (100%)
Chemical – wax Cracking with shape selective catalyst
-10 to –50 o C
Same or Lower
Generally 5 –10 Numbers Lower
Gas, Naphtha
50 –60 %
Chemical – wax Isomerization with shape selective catalyst
-10 to –50 o C
Same or Higher
Generally 5 –10 Numbers Higher
Gas, Naphtha, Jet, Diesel
55 – 65%
Product Comparison of Different Dewaxing Processes – Constant Refining Severity
Waxy V.I.
IDW/MSDW
SDW
CDWDewaxed V.I.
Waxy Viscosity
Dewaxed Viscosity
CDW
SDW
IDW/MSDW
Isodewaxing preserves V.I. and viscosity of waxy oil.V
.IV
isco
sity
ISODEWAXING
During the Dewaxing Step, Wax Molecules Are Either Removed, Cracked, or Converted
Wax Molecules
Example: nC20, 174 V.I., Melting Point 37 oC
^^^^^^^^^^^^^^^^^^^^^^^^^
Solvent Dewaxing
Conventional CatalyticDewaxing
Isodewaxing/MSDW
Wax^^^^^^^^^^^ ^ + ^^
C3 C4, C5, C6iC20: 164 V.I., Melting Point –2.5oC
Wax separated from Oil
^^^^^^^^^^
Wax Cracked to Light gases & Naphtha
Wax Isomerized to Lube Oil
Existing Refinery – Over view
• Integrated Lube and Fuel complex which operate in tandem
• Segregated crude/vacuum units which process low sulfur/non lube bearing and lube bearing crudes.
• Fuel Block • Fluid Catalytic Cracking (FCC)• Diesel Hydrodesulphuriser
• Lube Block• Extraction units• Hydrofinishing units• Solvent dewaxing unit
CDU1
CDU2
VDU 1
VDU2
VDU3
SEU
PDA
SDU
FCC
H2
DHDS
LPG
SR Naphtha
H2
High Sulfur Crude
Low Sulfur Crude
VR
DAO
SPINDLE150 N500N
BS
IO-100IO-1600
SIMPLIFIEDSIMPLIFIED REFINERY- EXISTINGREFINERY- EXISTING
DIESEL
GASOLINE
NAPHTHA
FUELS BLOCK
LUBEBLOCK
LUBE REFINERY PROCESS UNITSLUBE REFINERY PROCESS UNITS
IOH
P DU
LOBS
SSEEU U
PPDDAA
ASPHALT
VTB
TOBS
150N
500N
1300N
BS ( ( 3 3 Nos )Nos )
IO-100
VVDDUU
PG
RCO
NM
P
EX
TR
AC
TIO
N
SDU
SDA
VPS
Extracts Spindle SS-I SS-II
DAO
Spindle Raffinate
150 N Raffinate
500 N Raffinate
IO-100
IO- 1600
Spindle
150 N500 N
BS
IO-100
IO -1600
Base Oil Processing Scheme- ExistingBase Oil Processing Scheme- ExistingGroup I Base OilGroup I Base Oil
1) Arab Mix Crude processed in Lube blockNotes
BS Raffinate
VACUUM DISTILLATION UNITVACUUM DISTILLATION UNIT
• DISTILLATION IS SEPARATION OF PRODUCTS BY
DIFFERENCE IN BOILING POINT
• DISTILLATION OF REDUCED CRUDE OIL UNDER
VACUUM
• SEPARATION UNDER VACCUM TO AVOID
DECOMPOSITION OF CRUDE
• MAIN PRODUCTS ARE VACUUM GAS OIL, DISTILLATES
FOR LUBES & VTB.
• COLOR, VISCOSITY, FLASH POINT OF SIDESTREAMS
AND VTB PEN ARE MONITORED.
SOLVENT EXTRACTION UNITSOLVENT EXTRACTION UNIT
• REMOVAL OF AROMATICS FROM DISTILLATE
USING NMP AS SOLVENT BY LIQUID - LIQUID
EXTRACTION PROCESS . ORIGINALY PHENOL
WAS USED AS SOLVENT.
• IMPROVES VISCOSITY INDEX.
• IMPROVES COLOR, THERMAL & OXIDATION
STABILITY.
• REDUCES AROMATIC CONTENT
HYDROFINER UNITHYDROFINER UNIT
• FIXED BED CATALYTIC HYDROGENATION
PROCESS
• HYDROGEN IS USED AS TREAT GAS
• IMPROVES COLOR,COLOUR STABILITY,
OXIDATION STABILITY.
• REDUCES SULPHUR & NITROGEN
CONTENT
PROPANE DEWAXING UNITPROPANE DEWAXING UNIT
• PHYSICAL SEPARATION PROCESS
• WAX IS CRYSTALLISED AT LOW
TEMPERATURES AND REMOVED BY
FILTERING IN ROTARY DRUM FILTERS
• PROPANE IS USED AS SOLVENT AND
AUTOREFRIGERANT.
• IMPROVES THE POUR POINT OF LUBE
OIL BY REMOVING WAX
PROPANE DEASPHALTING UNITPROPANE DEASPHALTING UNIT
• PRODUCES DE ASPHALTED OIL BY REMOVING
ASHPHALT FROM VACUUM TOWER BOTTOMS (VTB)
• ASPHALT REMOVAL CARRIED OUT BY
COUNTERCURRENT LIQUID - LIQUID EXTRACTION
• PROPANE USED AS SOLVENT
• PRODUCES HIGH QUALITY BRIGHT STOCK OR
FEEDSTOCK FOR FCC UNIT AND ASPHALT FROM
VTB.
• DECREASES ASPHALTENE, RESIN, CARBON RESIDUE,
SULPHUR AND NITROGEN CONTENT.
• IMPROVES COLOUR
Existing LOBS Processing scheme
Solvent Extraction Units (SEU) + Hydrofinishers + Solvent Dewaxing unit
Multiple units (SEU & HF) are provided to allow simultaneous processing of different grades.
No wax production is considered. Slack wax is processed in FCC.
DAO from SDA is processed in SEU & SDU to produce BS.
Existing LOBS Processing scheme
Present quality of LOBS (especially Sulfur & saturates ) are far away from Group II specifications.
Existing Hydrofinishers are low pressure (58 bar) and hence are not suitable for meeting Group II specs.
Even with deeper extraction level of aromatics & sulfur can not be of Group II quality
Production of Group II base oils require some form of hydroprocessing route.
Demand PatternDemand Pattern
Setting Demand Pattern
Total make 200,000 TPA 300,000 TPA API category Remarks
Base Oil(‘000 TPA)
Spindle 15 15 Group II Saturates >99%
150 N 25 80 Group II Saturates >99%
500 N 115 160 Group II Saturates >99%
IO-100 5 5 Group I/Present
IO-1600 5 5 Group I/Present
BS 35 35 Group I/Present
Total Group II base oils
155 255
Base oil Upgrading scheme -1Group –II oils 255, 000 TPA
Add a New 150 bar Hydrotreater (HDT) to existing scheme.
Raffinates from existing SEU are processed in a high pressure hydrotreater.
Hydrotreated raffinates are further processed in existing Solvent Dewaxing unit.
HD
T (1
50
b
ar)
35
0,0
00
NM
P
EX
TR
AC
TIO
N
SDU
SDA
VPS
Distillate to fuel Complex
Extracts Spindle SS-I SS-II
DAO
Spindle Raffinate
150 N Raffinate
500 N Raffinate
IO-100
IO- 1600
Spindle 15,000 150 N 80,000
500 N 160,000 BS 35,000
IO-100 5,000 IO -1600 5,000
Base Oil Upgrading Scheme- 1Base Oil Upgrading Scheme- 1Group II Base Oil : 255,000 TPAGroup II Base Oil : 255,000 TPA
1) Arab Mix Crude processed in Lube blockNotes
2) VI of 500N 104
Base oil Upgrading scheme -1Group –II oils 255, 000 TPA
Findings of the scheme.
Advantages:Base oils meet all the bare minimum Group II specs.
Aromatic levels in base oils, especially 500 N will be around 10%. (disadvantage?)
Aromatics in 150 N will be around 5% (disadvantage?)
Base oil Upgrading scheme -1Group –II oils 255, 000 TPA
Findings of the scheme.
Disadvantages:Yield loss (for 500 N) from HDT is significant, for the
same LOBS production, raffinate feed reqmt is more and hence higher HDT unit capacity.
Higher capital cost because of higher HDT capacity
Base oil Upgrading scheme -2Group –II oils 255, 000 TPA
Add a New 150 bar Hydrotreater (HDT) + New Hydroisomerisation (HDW) unit to existing scheme.
Raffinates from existing SEU are processed in a high pressure hydrotreater.
Hydrotreated raffinates are further processed a new Hydroisomerisation unit.
Other Base oils are processed in conventional route.
Base Oil Upgrading Scheme- 2Group-II Base Oils : 255,000 TPA
VPS
HD
T (1
50
b
ar)
28
90
00
NM
PE
XT
RA
CT
ION
HY
DR
O I
SO
M/
HY
F
SDA
SDU
Distillate to fuel Complex
Extracts
SS-I
DAO
Spindle
SS-II
Spindle Raffinate
150 N Raffinate
IO-100
IO- 1600
Spindle 15,000 150 N 80,000
BS BS 35,000
IO-100 5,000
IO- 1600 5000
500 N 160,000 500 N Raffinate
1) Arab Mix Crude processed in Lube blockNotes
2) VI of 500N 104
Base oil Upgrading scheme -2Group –II oils 255, 000 TPA
Add a New 150 bar Hydrotreater (HDT) + New Hydroisomerisation unit to existing scheme.
Hydroisomerisation catalyst is noble metal catalyst and can tolerate low levels of Nitrogen & other contaminants
Hydrotreater prepares the feed for this unit. Hydroisomerisation unit upgrades this feed by
converting wax to high value VI base oils.Hydrofinishing step is included in this scheme.
Base oil Upgrading scheme -2Group –II oils 255, 000 TPA
Findings of the scheme.
Advantages:Base oils meet or exceed all Group II specs. Aromatic levels in base oils < 1 %Yield loss in HDT compensated in HDW unit.Lower raffinate feed reqmt less than scheme-1.Lower raffinate feed reqmt increases the feed to FCC unit.
Base oil Upgrading scheme -2Group –II oils 255, 000 TPA
Findings of the scheme.
Advantages:The pressure levels of HDT & HDW can be kept same to
facilitate integrated operation and both units will have a single recycle loop.
Lower capital cost than scheme-1.Provides flexibility for staged investment. Implement
scheme-1 and at a later stage integrate HDT with HDW.
Base oil Upgrading scheme -2Group –II oils 255, 000 TPA
Findings of the scheme.
Disadvantages:Destroys wax. In this particular case, wax is not a
product.
Base oil Upgrading scheme -3Group –II oils 255, 000 TPA
Add a New 150 bar Hydrotreater (HDT) + New Hydroisomerisation (HDW) unit for slack wax
Raffinates from existing SEU are processed in a high pressure hydrotreater.
Slack wax from SDU is processed in a new Hydroisomerisation unit.
Other Base oils are produced in conventional route.
HD
T (1
50
b
ar)
35
0,0
00
NM
P
EX
TR
AC
TIO
N
SDU
SDA
VPS
Distillate to fuel Complex
Extracts Spindle SS-I SS-II
DAO
Spindle Raffinate
150 N Raffinate
500 N Raffinate
IO-100 IO- 1600
Spindle 15,000 150 N 80,000
500 N 160,000 BS 35,000
IO-100 5,000 IO -1600 5,000
Base Oil Upgrading Scheme- 3Base Oil Upgrading Scheme- 3Group II Base Oil : 255,000 TPAGroup II Base Oil : 255,000 TPA
1) Arab Mix Crude processed in Lube blockNotes
2) VI of 500N 104
HD
W/
HF 150 N 70,000
Slack wax 100,000
Group III
Base oil Upgrading scheme -3Group –II oils 255, 000 TPA
Findings of the scheme.
Advantages:Base oils from SDU meet bare minimum Group II specs. Slack wax processed in HDW produces 150 N of Group III.Maximum utilization of SDU capacityOption for staged investment.
Base oil Upgrading scheme - 3Group –II oils 255, 000 TPA
Findings of the scheme.
Disadvantages:Aromatic levels in 500 N will be around 10%.
Higher capital cost because of high RHT unit capacities & wax Isomerisation unit.
Base oil Upgrading scheme -4Group –II oils 255, 000 TPA
New Hydrocracker + New Hydroisomerisation
All side streams from VDU are routed to Lube hydrocracker (LHCU).
The waxy streams from LHCU processed in HDW.
LHCU also produces hydrocracked VGO (non-lube material) which is routed to FCC.
Base Oil Upgrading Scheme- 4Group II Base Oil : 255,000 TPA
FCCU870,000
Light FeedHeavy Feed
Lube Hydrocrac
kerBlocked
Operation 1340,000
TPA
HD
W2
90
,00
0
TP
A
1) Arab Mix Crude processed Notes
2) VI of 500N > 120
Spindle Oil Waxy 150N
Waxy 500N
<360ºCSpindle150 N500N
Heavy Diesel
Streams
VDU Side Streams Hydrocracker DS VGO
0.005% Sulfur
360ºC & lighter
Base oil Upgrading scheme -4Group –II oils 255, 000 TPA
Findings of the scheme.
Advantages:Flexibility to process higher volumes of high sulfur crudes.
Greatest crude flexibility.Base oils exceed Group II quality.FCC feed quality has significantly improved which results in
high yields of value distillates such as LPG, gasoline.Quality of FCC products w.r.t sulfur significantly improves.
Base oil Upgrading scheme - 4Group –II oils 255, 000 TPA
Findings of the scheme.
Disadvantages:High Hydrogen consumptions and hence additional
hydrogen plant required.Existing Lube processing facilities become
redundant.Highest capital costs.
Utilization of Existing Lube processing facilities
Existing 60 bar Hydrofinishers.
The pressure levels of HDT & HDW are around 150 bar. Existing HF can not be used because the product quality as measured
by aromatics and color would actually degrade by using these HF
Existing Solvent Dewaxing Unit: In scheme-2 only BS & IO’S are processed in SDU. This results in
underutilization of SDU. Reduce the 500 N Group II requirements. Utilize the existing scheme
to produce 500 N, BS & IOs of Group I quality. This will allow the refiner the greatest flexibility to produce Group I as
well as Group II depending on market demand.
Integration of Hydroprocessing and Solvent Extraction
SEUSEU SDWSDW HFHF
HDTHDT Hydro ISOMHydro ISOM HDFHDF
Group IIIGroup III
Group IIGroup II
Group I
Slack Wax/Soft WaxSlack Wax/Soft WaxRaffinate Raffinate
HydroprocessingHydroprocessing can be Integrated with Solvent Extraction plants to can be Integrated with Solvent Extraction plants to improve product Quality/Yield & flexibility to make Group II/III Oilsimprove product Quality/Yield & flexibility to make Group II/III Oils
Base Oil Upgrading Scheme- 5Group-II Base Oils : 155,000 TPA
VPS
HD
T (1
50
b
ar)
17
60
00
NM
PE
XT
RA
CT
ION
HY
DR
O I
SO
M/
HY
F
SDA
SDU
Distillate to fuel ComplexExtracts
SS-I
DAO
Spindle
SS-II
Spindle Raffinate
150 N Raffinate
IO-100
IO- 1600
Spindle 15,000
150 N 25,000
BS Raffinate BS 35,000
IO-100 5,000
IO- 1600 5000
500 N 115,000 500 N Raffinate
1) Arab Mix Crude processed in Lube blockNotes
2) VI of 500N 104
Addl feed to FCC
Observations & Conclusions
If an Extraction unit is present, it is more economical to produce Group II LOBS via raffinate HDT route.
Staged investment is an option for the refiner. In the first phase HDT can be considered and at a later stage Hydro Isom can be added.
Observations & Conclusions Quantity of 500 N affects the over all economics. Since the trend is
to move towards lighter viscosity grades, refiner has to judiciously decide the break up of Group I & Group II.
Consider VI of LOBS (especially 500 N with in Group II). Increasing the VI beyond Group II requirements will reduce the yields, increase the capital investments and hence not economical.
While revamping the FCC unit, consider additional feed in FCC unit, keeping in view the fluctuating demand of LOBS.
Observations & Conclusions Can LOBS quality improvement alone justify investment?
This is a difficult question to answer.
With 255,000 TPA of Group II LOBS, revenues are better but these do not give better IRR because of higher capital costs & impact on Fuel block products.
With 155,000 of Group II LOBS, IRR could be better. Thus each refiner should evaluate the economics based on target LOBS production.
While maximizing LOBS production, consider maximizing value added products such as LPG from FCC etc. to improve over all refinery profitability.