3 Base Oil Hydroprocessing · (duo\ fdwdo\wlf ghzd[lqj zd[ k\gurfudfnlqj uhsodfhg vroyhqw ghzd[lqj...

$: 3 Base Oil Hydroprocessing · (duo\ fdwdo\wlf ghzd[lqj zd[ k\gurfudfnlqj uhsodfhg vroyhqw ghzd[lqj /rqj fkdlq qrupdo sdudiilqv zd[ eurnhq lqwr vpdoohu prohfxohv ixhov erlolqj udqjh$
III. Base oil manufacturing: hydroprocessing

Amy Claxton, CEOMy Energy Consulting and Training

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


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


Conversion permanently changes and rearranges molecules


Aromatics


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.


• 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


Agenda





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


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)


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


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


• 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

xing

( 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


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


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

xing

(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


1994: Another great year for Chevron


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


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


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


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


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


Where did the Bright Stock go?

• Hint: selective molecule smashing (conversion) isn’t always 100% “selective”



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



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


Where did the wax (long chain linear paraffin go?


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


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





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


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


• 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


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


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


• 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


Hydroprocessing is a “conversion” process .... selective smashing!

Aromatics


Paraffins

Naphthenes Remaining base oil

molecules

Removal via destruction, rearranging

Removeunwanted molecules


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


Thank you


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