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Agenda
1. Hydroprocessing terminology & overview
2. Base oil hydroprocessing – newer technology that the base oil industry world
3. Example: 95 VI base oil from Arab Light crude
17 February 2020 Base Oil Hydroprocessing 2
Solvent processing was a molecule “separation” process
17 February 2020 Base Oil Hydroprocessing 3
Aromatics
and very long paraffins (wax)
Paraffins
NaphthenesRemaining base oil
molecules to tankage
Removed unwanted molecules via solvent separation
Hydroprocessing is a molecule “conversion” process
• .... selective molecule smashing (conversion)rather than molecule sorting
17 February 2020 Base Oil Hydroprocessing 4
Conversion permanently changes and rearranges molecules
17 February 2020 Base Oil Hydroprocessing 5
Aromatics
and very long paraffins (wax)
Paraffins
Naphthenes Remaining base oil molecules to tankage
Remove undesirable molecules via destruction to
lighter molecules, rearranging
What molecules are we trying to convert? Same as before.
17 February 2020 Base Oil Hydroprocessing 6
• Aromatics – unstable – oxidize more easily; saturate to form
naphthenes, ring opening to form paraffins
• Paraffins – good stability under heat and pressure; isoparaffins have
the highest VI and stability
• Naphthenes – fairly good stability, excellent solubility; saturated cyclo
(ring) compounds created via aromatic saturation
Hydroprocessing means the use of hydrogen and catalysts
Mild Moderate Severe
Hydrotreating
Hydrofinishing Mild hydrocracking
HydroconversionHydrocracking
Hydroisomerization
• Catalyst is selected to perform specific molecular actions
• Ring opening, saturation, cleaving (cracking), branching
500#
Pressure defines hydroprocessing severity
3000#1500#
More hydrogen and pressure required for worse quality feeds
17 February 2020 Base Oil Hydroprocessing 7
Agenda
1. Hydroprocessing terminology & overview
2. Base oil hydroprocessing – newer technology that the base oil industry world
3. Example: 95 VI base oil from Arab Light crude
17 February 2020 Base Oil Hydroprocessing 8
1950s: early lab hydrocracking to remove aromatics and wax
Concept: replace solvent separation with hydrocracking to remove aromatics and wax
Aromatics
CRACKING
Destroys
aromatics to
improve VI &
saturates
Wax
CRACKING
Destroys wax
to improve
pour point
base oilLight
Mid
Heavy
Reduced crude oil
- Early catalyst technology: too much cracking
- Remaining oil was only slightly higher VI and very low yield
17 February 2020 Base Oil Hydroprocessing 9
1960s – 1970s base oil hydrocracking developments
95 VI but poor base oil yields and low value fuel by-products due to over-cracking
VGO / lube fraction Low value fuel products
95 VI base oil – still low yield
• Commercialized at Idemitsu Kosan (Chiba) and Sun Oil (Puerto Rico) using Gulf Oil Technology (acquired by Chevron in 1985)
17 February 2020 Base Oil Hydroprocessing 10
1980s: Improved lube hydrocracking catalysts, more selectivity
Higher base oil yields, higher value fuel by-products
higher value fuel byproducts
95 VI base oil
VGO / lube fraction
• Economically viable for many crude slates
17 February 2020 Base Oil Hydroprocessing 11
Today’s lube hydrocracking replaces solvent extraction
• Feed molecules reshaped, cracked, rings saturated with hydrogen (aromatics saturation)
Light
Mid
Heavy
Crude Oil
Va
cuum
D
istil
latio
n
Mul
ti st
age
H
ydro
crac
kin
g
gas & fuel products
hydrogen
95 VI+, high pour lube hydrocrackate
17 February 2020 Base Oil Hydroprocessing 12
• Waxy, long chain normal paraffins mostly unaffected (dewaxing step still needed)
Early catalytic dewaxing (wax hydrocracking) replaced solvent dewaxing
• Long chain normal paraffins (wax) broken into smaller molecules (fuels boiling range)
• Improves pour point by cracking wax out of the lube boiling range; low lube yields
fuel products
Cat
alyt
ic d
ewa
( w
ax
hyd
rocr
ack
ing)
gas
Hyd
rocr
ack
ing
Va
cuu
m
Dis
tilla
tion
gas
95 VI, low pour lube hydrocrackate
hydrogen
First Generation: Catalytic dewaxing (CDW): hydrocracked the long wax chains
17 February 2020 Base Oil Hydroprocessing 13
1984: A great year for Chevron
Commercialization of multi-stage lube and wax hydrocracking, Richmond CA USA
Lube
Hydrocracking
Improve saturates &
viscosity index
Improve pour point
95 VI base oilsCatalytic
Dewaxing (Wax Hydro-
cracking)
Isolate lube molecules
Light
Mid
Heavy
Crude Oil
Dis
tilla
tion
hydrogen
Useful on crudes that are less paraffinic (ANS) - but yield is proportional to crude paraffin content
17 February 2020 Base Oil Hydroprocessing 14
Today’s hydrodewaxing to replace solvent dewaxing
• Hydroisomerization catalyst rearranges (isomerizes) linear paraffins to branched iso-paraffins
• Iso-paraffins have lower pour and higher VI than straight chain paraffins
Current Generation: Hydro-dewaxing (HDW): hydro-isomerizes wax
fuel products
Hyd
rod
ewa
(h
ydro
isom
eriz
atio
n)
gas &
Hyd
rocr
ack
ing
Va
cuu
m
Dis
tilla
tiongas
hydrogen
95 VI+, low pour lube base oil
17 February 2020 Base Oil Hydroprocessing 15
1994: Another great year for Chevron
17 February 2020 Base Oil Hydroprocessing 16
Commercialization of multi-stage lube hydrocracking and wax hydrodewaxing (HDW) using wax isomerization, Richmond CA USA
Lube
Hydrocracking
Improve saturates &
viscosity index
Improve pour point
95 VI base oilsCatalytic
Dewaxing (Wax Hydro-
isomerization)
Isolate lube molecules
Light
Mid
Heavy
Crude Oil
Dis
tilla
tion
hydrogen
Chevron’s proprietary hydrodewaxing process is called ISODEWAXING (“IDW”)
Put it together: HCU + HDW
• Lube hydrocracking + hydrodewaxing: higher lube base oil yields & quality
Lube Hydrocracking Unit Lube Hydrodewaxing Unit
VacuumGas Oil
Vacuum stripping or distillation
IntermediateTankage
VacuumStripper
Wide cut base oil
Recycle H2Makeup H2
Gu
ard
Rea
cto
r Lu
be
Hyd
rocr
ack
er To Fuels
Iso
me
riza
tion
D
ewa
xer
Hyd
rotr
ea
ter
Makeup H2
To Fuels
Recycle H2
17 February 2020 Base Oil Hydroprocessing 17
Lube hydroprocessing – one more step needed
• Products from hydrocracking and hydrodewaxing must be re-fractionated on the back end
Final distillation step required to correct viscosities – set to mimic solvent neutral viscosities (100N, 150N, 500N) used for decades by blenders
17 February 2020 Base Oil Hydroprocessing 18
1) Hydrocracking 2) Hydrodewaxing
VacuumGas Oil
VacuumStripper
Recycle H2Makeup H2
Gua
rdR
eact
or Lube
Hyd
rocr
acke
r To Fuels
Isom
eriz
atio
n D
ewax
er
Hyd
rotr
eate
r
Makeup H2
Recycle H2
3) Re-fractionation and blending
Light
Mid
Heavy
Wide cut base oil
Dis
tilla
tion
95 VI base oils
Put the four refinery processing steps together
1. Crude is fractionated via atmos and vacuum distillation into light and heavy VGO streams or “fractions”
2. Hydrocracking removes unwanted aromatics
3. Hydrodewaxing removes unwanted wax
4. Re-fractionation and blending to adjust viscosity
Hydro cracking
improves VI &
saturates
Light
Heavy
Hydro
dewaxing
improves pour
point
base oil
Reduced crude oil
Re-fractionation
and blending
Adjust viscosity
17 February 2020 Base Oil Hydroprocessing 19
Base oil properties – where controlled
Property Process where controlled
Viscosity Crude distillation and back-end re-distillation after hydrocracking / hydrodewaxing
VI Hydrocracking+ VI increases as aromatics are removed
Saturates Hydrocracking + Sats increase as aromatics are removed
Pour Point Hydrodewaxing+ Pour point decreases as wax is removed
Light
Mid
Heavy
Dis
tilla
tion
Aromatics
Wax
17 February 2020 Base Oil Hydroprocessing 20
Differences in hydroprocessed vs. solvent processed base oils
• Water white; color highly valued in some applications
• Very low aromatics; better oxidative stability under heat and pressure
• No sulfur; sulfur must be re-added as an anti-oxidant in engine oil formulations
• Excellent soot handling in heavy duty engine oil applications
• Improved finished lubricant formulation flexibility
• Less soluble – a negative for some applications
S100N S600N S150N
Solvent processed
500N220N100N
Hydroprocessed
Photos courtesy of Dr. H.E. Henderson, KEPC Consulting
17 February 2020 Base Oil Hydroprocessing 21
Where did the Bright Stock go?
• Hint: selective molecule smashing (conversion) isn’t always 100% “selective”
17 February 2020 Base Oil Hydroprocessing 22
Where did the Bright Stock go?
Viscosity reduction occurs across hydrocracking – by definition, intentionally
Mu
lti s
tag
e H
ydro
crac
kin
g
Hydrocracker Fuels from hydrocracker:lower viscosity
Feed :higher viscosity
Lubes from hydrocracker :lower viscosity
17 February 2020 Base Oil Hydroprocessing 23
Where did the Bright Stock go?
High viscosity, big molecules are converted (“cracked”) out of the lube boiling range into lighter viscosity, smaller molecules in the fuels boiling range
Final lube products from about 70N to ~ 500N viscosity
No heavier viscosity … no Bright Stock
17 February 2020 Base Oil Hydroprocessing 24
Where did the wax (long chain linear paraffin go?
17 February 2020 Base Oil Hydroprocessing 25
Hint: we did it on purpose
Where did the wax (linear paraffin) go?
• Branched (iso) paraffins are liquid at room temp; short chain paraffins are fuels boiling range
• Either way, no more paraffin wax available from base oil hydroprocessing
17 February 2020 Base Oil Hydroprocessing 26
Long chain paraffins (wax) are solid at room temperature; must be removed to improve pour point
Base oil from hydrodewaxing:
No long chain linear paraffins
Hyd
rod
ew
axin
gFeed to dewaxer:has long chain linear paraffins, aka “wax”
Agenda
1. Hydroprocessing terminology & overview
2. Base oil hydroprocessing – newer technology that the base oil industry world
3. Example: 95 VI base oil from Arab Light crude
17 February 2020 Base Oil Hydroprocessing 27
Let’s make hydroprocessed base oils
VGO streams are often processed in lube hydrocrackers based on “light” versus “heavy” VGO blocks using intermediate storage tanks
Re-distillation & blending
Va
cuum
Dis
tilla
tion
Reduced Crude
Light and Heavy VGO tankage
Light and Heavy VGO
blocks
Light
Mid
Heavy
Hydrocracking Hydrodewaxing
Finished tankage
Wide cut base oil Light
Mid
Heavy
Dis
tilla
tion
17 February 2020 Base Oil Hydroprocessing 28
Example: let’s make hydroprocessed base oils
How much base oil from refinery running 100 kBD Arab light crude?
• Arab Light has a 75% - 76% yield across catalytic hydrocracking, and 85 – 86% yield across catalytic dewaxing
Hydro-
Dewaxing
Lube
HydrocrackingBase Oils
Light
Heavy
32 kBD Reduced Crude Oil
Dis
tilla
tion
Light
Mid
Heavy
Dis
tilla
tion
• Assume minimal losses from final distillation and blending
17 February 2020 Base Oil Hydroprocessing 29
• Arab Light crude has ~ 32% VGO, of which about half is VGO boiling range for base oils
Example: let’s make hydroprocessed base oils
• ~ 10.4% base oil yield on Arab Light crude via hydroprocessing
10,440 b/d95 VI base
oil Hydro-
Dewaxing
Lube
Hydrocracking
Light
Heavy
33 kBD Reduced Crude Oil
Dis
tilla
tion
Light
Mid
Heavy
Dis
tilla
tion
17 February 2020 Base Oil Hydroprocessing 30
87%
HDW Yield
75%
HCU Yield
32,000 10,440
kBD base oil
16,000
HCU feed, b/d
Arab Light
Crude
100,000
Crude feed, b/d
Reduced crude, b/d
Compare solvent vs hydroprocessing base oil yields
• ~ 9.8 base oil yield on Arab light via solvent processing
• ~ 10.4% base oil yield on Arab Light via hydroprocessing
610 b/d x 365 days/yr x ~ $25/B margin over VGO = ~ $5M / year base oil profit
10,440 b/d – 9,830 b/d = 610 b/d more base oil via hydroprocessing
17 February 2020 Base Oil Hydroprocessing 31
87%
HDW Yield
75%
HCU Yield
32,000 10,440
kBD base oil
16,000
HCU feed, b/d
Arab Light
Crude
100,000
Crude feed, b/d
Reduced crude, b/d
83%
Dewaxing Yield
74%
Extraction Yield
32,000 9,830
kBD base oil
16,000
Extraction feed, b/d
Arab Light
Crude
100,000
Crude feed, b/d
Reduced crude, b/d
Objectives / agenda: separation versus conversion processes
17 February 2020 Base Oil Hydroprocessing 32
• SEPARATION: physical separation of crude molecules into
different streams via heating, fractionating, cooling, dissolving
Versus
• CONVERSION: chemical modification of crude molecules using
catalysts to change the molecules
• Undesirable molecules are physically modified using catalyst
and hydrogen
• Molecular “re-arranging” versus molecular ”sorting”
Objectives / Agenda
• Lube hydroprocessing: the technology that changed the base oil industry
I replaced solvent extraction with hydrocracking
And I replaced solvent dewaxing
with hydrodewaxing
1) Lube hydrocracking
(HCU)
Improve saturates and viscosity index
Improve pour point and viscosity index
base oil to tankage
2) Hydrodewaxing
(HDW)
hydrogen
3) Re-distillation
and blending
Re-establish viscosity grades
17 February 2020 Base Oil Hydroprocessing 33
Hydroprocessing is a “conversion” process .... selective smashing!
Aromatics
and very long paraffins (wax)
Paraffins
Naphthenes Remaining base oil
molecules
Removal via destruction, rearranging
Removeunwanted molecules
17 February 2020 Base Oil Hydroprocessing 34
Today’s lube hydroprocessing
• More synergistic with fuels refining processes
• Higher yield at equivalent VI and same feedstock
Hydrocracking
improves VI &
saturates
Light
Heavy
Hydro
dewaxing
improves pour
point
95 VI base
oil
Reduced crude oil
Re-
fractionation
and blending
reset viscosity
No more heavy viscosity base oil (i.e. Bright Stock), no more paraffin wax
17 February 2020 Base Oil Hydroprocessing 35