Croda 2007

PRIOLUBE, PERFAD, HYPERMER, EMKAROX AND EMKARATE are trademarks of Croda

High Performance Biodegradable Ester Lubricants

from Sustainable and Non-Sustainable Feedstocks

Andrew P Swallow (Technical Service Manager) John Eastwood (Technical Service Manager)Steven J Randles (Global Applications Director)

Agenda

• European ECO Labels• Renewability• Performance parameters• Natural esters• Oleochemical esters• Petrochemical esters

Existing Eco-labels in Europe

• The European Eco-label has been based largely on the existing eco-labels of individual European countries, specifically:

– Germany (Blue Angel)– Sweden (Swedish Standard)– Nordic Countries (White Swan)– France (NF Environment)– Holland (VAMIL Regulation)– Austria

An Eco-label for Europe

• In December 2004 the European Commission voted in favour of adopting a European Eco-label for Lubricants.

• The document was published in the Official Journal in the summer of 2005.

• A copy of the document is available at:http://europa.eu.int/comm/environment/ecolabel/product/pg_lubricants_en.htm

Renewable Raw Materials

• The lubricant shall have a carbon content derived from renewable raw materials that shall be:– => 50% for hydraulic oils– => 45% for greases– => 70% for chain saw oils, concrete release agents and

other total loss lubricants– => 50% for two-stroke oils

• Additive targets are difficult achieve– Biodegradability, bio-accumulation and toxicity targets are

difficult to achieve while meeting the correct performance

• Few formulations currently meet the criteria– A review of the European Eco-label will take place in 2008– Many of the European Eco-labels will continue in parallel

Lubricant Overview

• Biodegradability tends to decrease with increasing chain length, branching, aromaticity and saturation, and will be influenced by the nature of the structure

% Biodegradability

28 days OECD 301B

% Renewabilitycontent

Vegetable Oil 70 – 100 100

Mineral oil 20 – 40 0

PAO 20 – 60 0

Alkyl Benzene 5 - 20 0

Diesters 40 - 75 0 to 80

Aromatic ester 5 - 60 0

Polyol ester 20 - 90 0 to 85

Complex ester 20 - 90 0 to 85

Polyalkylene Glycol

10 - 70 0

Esters as Lubricant Base fluids

• Three general categories– Natural oils and fats

• Plant and animal derived

– Oleochemical derived esters • Fatty unsaturated esters (e.g. oleates, dimerates)• Fatty saturated esters (e.g. stearates, isostearates)

– Petrochemical esters • Diesters ( e.g. adipates, sebacates, azelates)

Oleochemical Derived Esters

• Broad technology platform enabling the preparation of biodegradable esters with viscosities ranging from approximately 10cSt up to 1000cSt at 40°C

• Not classified as dangerous for the environment, nor are they classified as harmful to aquatic organisms

• Generally do not bio-accumulate in the environment. Typical esters used in the formulation of environmentally acceptable lubricants (EALs) have Log Kow values ranging from 10 to 25

Petrochemical Esters

• Diester advantages are :– Long-life lubricants – High temperature operating conditions– Very low temperature environments– In addition, diesters have a low viscosity. Until recently they

have been the only real option for low viscosity lubricating oils

• Diesters disadvantages are:– Non renewable– Under new Eco-label criteria, petrochemical esters will

become useful only as co-base fluids and the amount that can be used in a formulation will be dictated by the application in which the lubricant will be used based on renewability

The Ester Reaction

Alcohol + Acid Ester + Water

- Catalyst

- Pressure

- Temperature

- Structure

- Acid

- Alcohol

Degree of Hydrolysis

• High levels of water

Degree of Esterification

• Low levels of water

EsterificationHydrolysis

R - O - C - R1

= OH2OR - OH R1 - C - OH= O

Improving Hydrolytic Stability

• Esters are acid catalysed– Higher initial acid value the faster the breakdown– Tightly controlled manufacturing processes

• Careful additive selection– Anti-wear additives (use stable and low acid

value)– Anti-corrosion additives (neutral ones)

• Acid catchers– Epoxides or carbo-imides

Performance Trade-Offs

Degree of branchingor aromaticity

0 100

Biodegradability0

100Hydrolytic Stability

Perf

orm

ance

O – C – C –

= O

H2O

StericHinderance

Polyol Ester

Performance Trade-Offs

Iodine value

Low High

Low Temp Operability0

100Oxidative Stability

Perf

orm

ance

O

O

O

O

O

O

PyrolysisWax formation

Oxidation

Hydrolysis

Natural Triglyceride

Optimizing Pour Point

Ester Pour Point, °C

TMP oleate (unsaturated C18) -51

TMP stearate (saturated C18) +45

TMP isostearate -30

PE branched C9 +30

PE linear C9 +8

PE branched C8 +8

Mixed branched PE -38

Mixed linear and branched PE -48

PE = Pentaerythritol

Low Temp Flow- Molecular weight- Degree of unsaturation- Structural diversity- Degree of branching

“Regular shaped structures” can flocculate and crystallize over time. Pour point is not always a particularly reliable measurement

Low Temperature Fluidity

Viscosity vs Storage time at - 30 °C

02000400060008000

1000012000140001600018000

0 50 100 150 200

Time (h)

Vis

cosit

y (

cS

t)

TMPO

Modified

ISO 46 Ester Comparison

Physical Property Diester + Complex

ester

StandardTMP Oleate

ModifiedTMP

Oleate

Saturated Polyol Ester

Saturated Opt. Ester

Ester A Ester B Ester C Ester D Ester E

Raw material source Petro Oleo Oleo Oleo Oleo

Viscosity at 40°C, cSt 46 48 44 46 45

Viscosity at 100°C, cSt 8.1 9.8 8.7 8 8.8

Viscosity Index 150 196 181 143 180

Viscosity at -30°C, cSt after 72hrs

9,500 5,500 to 16,000

3,800 9,500 4,400

Pour point, °C -42 -51 -54 -42 -45

Iodine value <1 84 72 2 <1

Dry TOST Test hours(+1.5% RC9321)

>>4000 500 540 >>4,000 On test>1,000

Biodegradability28 days OECD 301B, %

61 84 99 85 77

Renewability, % 17 86 85 85 78*Northern Europe would aim for <5,000 cSt at -30°C after 72hrs

Other Viscosities

Oleo.derived

Petro.derived

Oleo.derived

Oleo.derived

Oleo.derived

Oleoderived

Oleoderive

d

Ester F Ester G Ester H Ester I Ester J Ester K Ester L

Viscosity 40°C, cSt 11 26 35 65 138 320 1040

Viscosity 100°C, cSt 3.0 5.3 7.5 13 17.6 35 90

Viscosity Index 136 139 193 208 140 150 167

Pour point, °C -33 -54 -42 -21 -33 -40 -24

Iodine value 1 <1 75 90 3 <1 4

Dry TOST test hours(+2% RC9308)

>4,000 >4,000 500 500 >4,000 >4,000 >4,000

Biodegradability28 days OECD 301B, %

78 74 81 64 70 70 63

Renewability, % 70 0 85 85 85 88 73Commercial high performance renewable esters have been developed for: Chain oils,Greases, Transformer oils, MWFs, 2T, Fuel additives, Marine and Offshore applications

Conclusions

• A wide range of esters commercially available that allow you to achieve optimum balance of– Biodegradability – Renewability– Stability– Low temperature properties– Cost

• Careful selection of additives are required to optimise hydrolytic stability

Contact

Andrew.Swallow@Croda.com+44 1642 435356Wilton CentreRedcar TS10 4RFEngland

Nina.Seryogina@Croda.com+ please add your details here

Disclaimer

• The information in this publication is believed to be accurate and is given in good faith but no representation or warranty as to its completeness or accuracy is made.

• Suggestions for uses or applications are only opinions. Users are responsible for determining the suitability of these products for their own particular purpose.

• No representation or warranty, express or implied, is made with respect to information or products including without limitation warranties of merchantability or fitness for a particular purpose or non-infringement of any third party patent or other intellectual property rights including without limit copyright, trademark and designs.

• Any trademarks identified herein are trademarks of the Croda group of companies