High Performance Lubricants From Renewable Sources

High Performance Lubricants from Renewable Sources

Dr A K Gupta, Ex. Scientist , Indian Institute of Petroleum, Dehradun

Current Trends

Due to steep increase in crude oil prices (current price ~$145/bbl) there is a renewed interest in alternatives to mineral oil based lubricants

The global drive towards the use of lubricants having minimum impact on the environment is increasing. This trend is likely to spread to more general adoption of alternative lubricant base stocks.

Recent environment, health and safety pressures are currently bringing about fresh evaluation of natural and synthetic alternatives for specialized application.

Due to high cost, synthetics may not penetrate the market to a large extent.

Therefore the focus is on lubricants and functional fluids derived from renewable natural sources.

Three major natural renewable sources for lubricating oils and functional fluids are:

1. Vegetable oils2. Starch, cellulose and sugars3. Algae oil

Main advantages of vegetable oil based lubricants over mineral oils include:

High biodegradability

Low toxicity

High flash point

High viscosity index

High lubricity

Compatibility with paints and seals

Main disadvantages of vegetable oil based lubricants :

Lower oxidation stability Poor low temperature properties Poor hydrolytic stability Price (Now comparable with mineral oil)

The properties of vegetable oil based lubricants can be tailor made to suit the specifications and performance by two mehods::

1. Through the use of additives

2. Suitable chemical transformation of vegetable oil such as hydrogenation, trans-esterification, epoxidation, condensation and acetylation reactions

In view of these trends, we have developed several lubricating oils and functional fluids from vegetable oils. These include:

1. Lube base oils2 Metal working fluids3 2-stroke Engine oil4 Hydraulic oil5 Insulating oil6 Gear Oil7 Lubricating Greases

All of these products can be prepared using vegetable oils and non-edible oils in particular.such as Rice bran oil, Mahua oil, Neem oil, Castor oil, Leanseed oil, Jatropha Curcas Oil, Salvadora Oil, Karanj Oil, Soyabean oil, rapeseed oil, algae oil and mixtures thereof.

Evaluation of bio-lubricants

The specific properties of the lubricating oils and functional fluids are determined using standard test methods The Bio-lubricating oils are likely to meet the current standard specs.

Base oils from vegetable oils

Vegetable oils can be transformed into lube base stocks by simple chemical transformations. The base oil properties depend upon the type of vegetable oil and chemical transformation applied.

Typical Properties of Vegetable Oil based Lube base stocks

Property Value range

Viscosity at 100°C, cSt 4 to 16

Viscosity Index 110-300

Pour Point, °C 0 to - 30 or below

The lubricity characteristics friction and wear data (HFRR Test) is much better than that of mineral oil base stocks.Volatilities are much lower than the mineral oil base stocks of corresponding viscosity range. Pour point depressants and VI improvers are not generally required. Other advantages include low deposits, low oil consumption, and high degree of environment friendliness. Cost marginally higher than mineral base oils

2-Stroke Engine Oil (2T-Oil)Vegetable oil ester lubricants are suitable for use as 2T-oils.

2T-Oil Performance

Vegetable oil based 2T-oil offers little better performance than conventional Mineral based or synthetic 2T-oils

Typical Product Properties & Specifications2T-Oils

Test - BIS 14234 2T oil Specs Bio 2T-Oil

Miscibility complete complete

K.Viscosity-cst at 100°C, min 6.5 7.62

K.Viscosity Index, min 95 114

Dosage % in fuel - 1

K.Viscosity-cst at 40°C 21.1 53.5

Flash Point, °C, min >70 218

Relative Density 0.88 0.882

Lubricity Index, min 95 170

Copper strip Corrosion, max 100°Cfor 3 hours

<1 <1

Panel Coking test, max 20 mg, Pass Pass

Oxidation, 1% max Pass Pass

Pour Point, °C -54 -24

Test - BIS 14234 2T oil Specs Bio 2T-Oil

Ash Sulphate % 0.12 0.08

TAN, mg KOH, max 0.05 0.055

Water, max 0.03 0.02

Detergency Index, min 95 200

Smoke Index, min 85 244

Piston varnish Index, min 90 200

Biodegradability % - >98

Advantages of Bio 2T-Oil

Likely to give lower emissions as compared to conventional 2T-Oils

Lower dozes ~ 1%

Comparable costs

More biodegradable

Provides better lubricity

Enhances oxidative stability of gasoline

Completely based on renewable sources

Bio-metal Working Fluids

Bio-metal working fluids are chemically modified vegetable oils with added additives.

Advantages of BioMetal Working Fluids

Reduces use of petroleum Offers better use of non-edible oils Produces fewer pollutant waste Product is almost completely biodegradable Provides better lubricity and extends tool life No health hazards due to toxic mist and effluents Helps employment general and rural upliftment

Typical Product Properties & Specifications

Metalworking fluid

Test - BIS 3065 Sol. oil Specs

Bio metalworking fluid

K.Viscosity-cst at 100°C 5.30

K.Viscosity-cst at 40°C, 15/30 26.37

Viscosity Index, min 145

Evaporation loss at 40°C 0.06

Flash Point, °C, min >100 210

Relative Density, 20°C 0.9403

Saponification value 16 min 17.5

Copper strip Corrosion, max 100°C for 3 hours

<1 <1

Iron chips corrosion test Pass Pass

Emulsion stability Pass Pass

Reactive sulfur nil nil

Test - BIS 3065 Sol. oil Specs Bio metalworking fluid


TAN, mg KOH, max 7 0.055

Panel cocker Deposit, mg, max 20 4

Wear Scar Dia, mm 0.683

Weld load, Kgf 140

Friction coefficient, mm 0.065


Test - BIS 3065 Sol. oil Specs Bio metalworking fluid


TAN, mg KOH, max 7 0.055

Panel cocker Deposit, mg, max 20 4

Wear Scar Dia, mm 0.683

Weld load, Kgf 140

Friction coefficient, mm 0.065


Bio-hydraulic Oils

Vegetable oil based Hydraulic oil formulations offer several advantages over the mineral oil based or synthetic hydraulic oils.

Main advantages are:

Almost completely biodegradable Less volatile than petroleum and synthetics Have higher flash point, safe to use Provides improved fire resistance thereby reduces fire hazards


Hydraulic Oils

Test - BIS 3098/1983 Specs-VG22 Bio- Hydraulic Oils

Miscibility Complete 100 %

Viscosity-cst at 40°C, 19.8-24.2 23.7

Viscosity Index, min 90 220

Dosage % - 1

Viscosity-cst at 40°C 21.1 53.5

Flash Point, °C, min 160 175

Emulsion test, max 40-37-3(20) 10-39-1(20)

Copper Corrosion, max100°C for 3 hours

<1 <1

Oxidation, RBOT, minutes, min 149 303


TAN, mg KOH, max reported 0.08

Rust test B, min Pass on 24 hrs Pass

Foaming nil Nil

Seal test-vol/hard, max 4/4 3/3


Bio-insulating Oils

Insulating oils such as Transfer oils can be prepared by chemically modifying the vegetable oils.

The products are tested for typical characteristics as per specifications


Insulating Oils

Test - BIS 12463 Ins oil Specs Bio Insulating Oils

Miscibility complete 100 %

Viscosity-cst at 27°C, max 27 5.8

Density at 29°C, max 0.89 0.881

Interfacial Tension at 27°C min 0.04 Nm 50 Nm


Pour Point, °C max -6 -9

TAN, mg KOH, max 0.03 0.005

Reactive Sulfur nil Nil

Copper strip Corrosion, max100°C for 3 hours

<1 <1

Electrical strength, KV, min 30 39

Oxidation, TAN change, max 0.4 – 0.1 0.3

Oxidation, RBOT, minuts, min 195 221

SKValue - 65

Dissipation Fact, 90/27°C,min 0.002 0.08

Water, max 50 ppm 10 ppm

Specific Resistance at 90°C, min 0.5 – 5 x 1010 0.2 x 1012


Bio-gear Oils

Vegetable oil based Bio-gear Oils are suitable for industrial applications. The products offer better physico-chemical characteristics than synthetics or mineral oil based Gear oils.

Main advantages are:

Over 98% biodegradable High flash point Higher lubricity and viscosity Index Lower pour point Almost non-foaming

Typical Product Properties & SpecificationsGear Oils

Test - BIS 8406 specification Bio-gear Oils

Miscibility - 100 %

Viscosity-cst at 40°C 41.1 – 50.6 56




TAN, mg KOH, max nil nil


<1 <1

Lubricity, fric. Coefficient, - 0.057

Wear scar dia,mm - 0.332

Coking test, max 20 mg, max - Pass

Oxidation, RoBOT, minutes - 200

Rust test, 24 hrs in sea water nil nil

Ash Sulphate %, max 0.1 0.08

Water %, max 0.5 0.3

Foam test, on 3 sequence, max 10-10-10 0-0-0

Air release at 40°C, min., max 10 9


Lubricating Greases

Calcium, magnesium, Lithium and barium greases can be prepared from vegetable oils. Grease prepared from vegetable oils offer improved properties particularly with respect to VI, Flash point, pour point, Drop point, wear scar dia (WSD) and leakage.

Further the Grease is almost completely biodegradable


Li - GreaseTest - BIS 1448 Gear oil Specs Bio Lithium

Grease

Viscosity-cst at 100°C, min 21 45



Pour Point, °C 4 -9

TAN, mg KOH, max Nil nil

RoBOT oxidation, min 200 190


<1 <1

Grease Formulated ¯


<1 <1

Drop point °C, min 180 250

Consistency at 25°C, 60 DS 220-250 230

Friction Coefficient, mm - 0.065

Wear scar dia,mm - 0.232

Free organic acid %, max 0.3 Nil

Free alkalinity %, max 0.2 0.15

Leakage %, max 5 1.3

Rust test, 24 hrs in sea water nil Nil

Deposit , % nil nil

Water washout %, at 80°C max 6 4


Conclusions The base oils, lubricants and functional fluids from vegetable oils offer

better properties compared to synthetics and Mineral based products.

Vegetable oil based lubricants (Bio-lubricants) are ecofriendly and biodegradable

Comparable in cost to mineral oil based lubricants Provides better use of non-edible oils including Jatropha Curcas oil.

Documents

High Performance Lubricants From Renewable Sources