Mineral Oils - Nature’s Synthesis
Paraffinic
Cyclic/Aromatic
Low cost
Big mixture
Mineral Oil
Mineral oil refining removes many of the least desirable
components (e.g. aromatics, waxes) and modifies the rest
(e.g. hyrofinishing, hydrodewaxing and/or hydroprocessing)
Base Stock Component Properties
Paraffins Iso-Paraffins Naphthenes Aromatics
VI
very high
high
medium/low
lowest
high
low
lower
lowest
Traction
lowest
low
Volatility
low
low
higher
highest
Solvency
poor
fair
good
excellent
Oxidation
Resistance
good
good
lower
resistance
easily
oxidized
Pour point
medium/high medium/high
Synthetic Base stocks
• Synthesized hydrocarbons
• Synthesized non-hydrocarbons (typically containing
oxygen atoms)
Synthesized hydrocarbons
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•
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Polyalphaolefins
Polybutenes
Alkylated aromatics
Cycloaliphatics
Polyalphaolefins (PAO)
• Chain molecular structures synthesized from ethylene
polymerization
• High VI and high oxidation stability
• Low pour point, low traction and volatility
• Best as engine oil basestock. Most popular PAO is
polydecenes, which is the basestock of Mobil 1
Polymerization of ethylene
PAO Manufacture
R - CH = CH2
Polymerization
Hydrogenation
3
Hydrogenated trimers,
tetramers, etc.
Alpha-olefins
1-Decene
R - CH CH2 - CH H
CH
R x
Polydecene
“Ideal”
Actual
Synthetic Polyalphaolefin (PAO)
Hydrogenated Polydecene
From Crude Oil to Synthetic Lubricants
 Synthetics are usually sourced from crude oil
 Many manufacturing steps result in high cost
Crude Oil
Atmospheric
1-Decene
Distillation
Catalytic
Polymerization
Distillation
Distillation
Synthetic
Lubricants
Sales &
Marketing
Cracker Feed
Alphaolefins
Catalytic
Catalytic
Cracking
Polymerization
Hydrogenation
Blending
Polydecene
Formulation
Light Olefins
Separation
Ethylene
Additives
On sale at Walmart for $5.00
Polybutenes
• Synthezied through controlled polymerization of butenes and
isobutenes
• High dielectrics constant – electrical insulating oils
• Low thermal stability – metal working and compressor lubes
to decompose to gases
• High molecular weight polybutenes or polyisobutenes are
used as VI improvers
Alkylated aromatics
• Synthesized from alkylation of benzenes
• Very low pour point and low viscosity – subzero
temperature applications
Cycloaliphatics
• Synthesized naphthenes, multi-ring-structured molecules
• Develop a glasslike structure under high stresses to yield high
traction
• Used as traction-drive fluids, also used in rolling bearings to
reduce roller skidding
Synthesized non-hydrocarbons
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Organic esters
Polyglycols
Phosphate esters
Silicate esters
Polyphenyl esters
Organic esters
• Dibasic acid esters:
• Polyol esters:
Wide temperature range and good thermal stability
Used as base stocks for essentially all jet engine lubes
Polyglycols
• The largest single class of synthetic lubricant bases
• High VI and low pour point
• Used mainly as brake fluids and hydraulic fluids
Phosphate esters
• High fire resistance
• Used mainly as hydraulic fluids and compressor lubes
• Also used as antiwear additives by its formation of
phosphide films on metal surfaces
Silicate ester
• Extremely high VI > 300
• Used mainly as heat exchanger fluids
Polyphenyl esters
• Most thermally and oxidatively stable
• Used mainly as heat transfer fluids