substitution of group i base oils in industrial lubricants- applications in model ... ·...

Substitution of Group I base oils in industrial lubricants- applications in model hydraulic fluid formulations

Synthetic and Hydraulic Lubricants Norrby, Thomas1; Malm, Linda1; Salomonsson, Patrik1 1 Naphthenics TechDMS, Nynas AB, Nynashamn, Sweden. INTRODUCTION Group I mineral base oil is the workhorse of the industrial lubricants business. However, the world base oil market is currently undergoing rapid change, driven mainly by the technical demand from high performance automotive engine oil applications, impacting all lubricant applications. Some of these highly paraffinic base oils make their way into industrial lubricant formulations, so called over-blending (or non-technical demand). Important chemical and physical differences exist between these base oil types. The viscosity range covered is Gr I is wider, and the solvency offered by Group II and Group III, with rapidly increasing aniline points, and lower aromatic carbon type content, is far smaller than that of Group I base oils. Nynas has created a new range of products with kinematic viscosity and aniline point closely matching those of existing Solvent Neutral Group I base oils. We conducted studies in the new base oil, and on model hydraulic fluids based on these. The results suggest that it is indeed possible to reproduce the key features of Group I base oils, and to formulate hydraulic fluids based on these. CHANGING BASE OIL SLADSCAPE Group I mineral base oil is the workhorse of the industrial lubricants business. Today, 70 % of all Group I base oils are utilized in industrial applications, and 30 % are used in automotive, mainly HDDO and straight grade engine oil applications. The world base oil market is currently undergoing rapid change. Very large projects for the production of Group II and Group III have been completed in recent years in different regions of the world. Some estimates of the base oil market indicate that, by name plate capacity, the world market would be between 6 and 10 million metric tonnes per annum. This base oil glut spills over onto the Group I producers, which in 2015 alone has resulted in the announced closures in Western Europe of ca. 1.5 million metric tonnes, ca 20 % of the total regional base oil production, Table 1.

Company Location Capacity (tpa) Shell Pernis, Netherlands 370000 Total Gonfreville, France 480000 Colas Dunkerque, France 290000 Nynas Hamburg, Germany 165000 Kuwait

Petroleum Rotterdam, Netherlands

250000*

*= 1Q, 2016 Table 1. Announced capacity rationalisation, Western Europe, 2015. Thus, rapid changes in the base oil market, driven mainly by the technical demand from high performance automotive engine oil applications, are impacting all lubricant applications. IMPACT ON INDUSTRIAL LUBRUICANTS Some of these highly paraffinic base oils make their way into industrial lubricant formulations, so called over-blending (or non-technical demand) [1]. However, many important chemical and physical differences exist between these base oil types. The viscosity range covered in Gr I is wider, providing much needed high viscosity to industrial gear oils, greases and engine oils, Table 2. The solvency offered by Group II and Group III, with rapidly increasing aniline points, and lower aromatic carbon type content, is far lower than that of

Group I base oils. Thus, some negative effect on the blending of industrial lubricants based on Group II or Group III base oils with existing Group I based industrial product can be foreseen, and have indeed been reported from the field.

API group Light

neutral

Medium

neutral

Heavy

neutral Group I 38% 13% 33% Group II 55% 25% 20% Group III 80% 20% none

Table 2. Relative base oil yield in different viscosity grades. We propose that the resulting “collateral” damage to the industrial lubricants business could be mitigated by Group I replacement fluids, such as these presented in this study. EXPERIMENTAL WORK Nynas has created a new range (NR) of products with Kinematic Viscosity (KV), Viscosity Index (VI) and Aniline Point (AP) closely matching those of existing Solvent Neutral Group I base oils. We conducted a low temperature study, where the treat rate response of a Pour Point Depressant (PPD) additive was investigated. Four reference elastomer materials (two NBRs, one H-NBR and one CR) have been investigated with respect to mass and hardness changes upon immersion in the new range base oils, and in reference base oils and hydraulic fluids. These model fluids have then been tested with respect to physical and chemical properties. They have also been compared to commercially available hydraulic fluids in a miscibility study. Particular attention was paid to oxidation stability, elastomer compatibility, and physical properties such as filterability, foaming tendency, air release, and demulsibility. The properties of these new products are described in a previous publication [2]and more information is available on www.nynas.com. RESULTS AND DISCUSSION In this study, we outline the design and testing of new range of specialty base oils, with its roots in Nynas’ naphthenic heritage. We set out to formulate one new range series to closely match the Kinematic Viscosity (KV) and Aniline Point (AP) of a reference set of Solvent Neutral Group I base oils, from 70 to 600 (SUS at 100 °F). We also developed a second generation of these new base oils with ISO VG grade Kinematic Viscosity, and with Viscosity Index (VI) of 95 or more, as many end users find also the VI to be very helpful. We matched the KV, AP and VI according to our design expectations. The first applied study was in low temperature properties, especially the treat rate response and expression of added Pour Point Depressant (PPD) additive. We could establish a new, lower recommended use treat rate, at 50% below conventionally used, for the new base oils. We conclude that a combination of lower content of n-alkane wax precursor molecules, in combination with a higher content of multi ring naphthenic molecules contribute to the very good low temperature performance. This property was also found to be retained in the fully formulated model industrial and mobile hydraulic fluids that we developed, based on these new base oils. The purpose of the elastomer compatibility study was primarily to confirm out hypothesis that a solvency retained at similar levels as found in Group I base oils, would result in very similar elastomer-fluid interaction, and retained seal material behaviour. Specifically, we wanted to make sure that seal hardness and mass changes were of similar magnitude and in the same direction, as not to present the seal material with any additional challenges to satisfy the design need in a machine construction. We could determine that the elastomer material response to the new base oils met these expectations, and that our screening method was sufficiently sensitive, as seen in the response vs Chloroprene rubber (CR). We conclude that these elastomer experiments would serve as a no-harm screening study, and lends further support to our approach to Group I replacement base oils. For more extensive data, please see [2]. The model hydraulic fluids, four in all, that were prepared by blending of the New Range base oils with commercially available industry standard additives displayed the desired and expected properties. Close comparison, and miscibility testing, versus two commercially available hydraulic fluids indicate that the task of

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formulating and testing hydraulic fluids, based on our new base oils, would be feasible. As expected, the model hydraulic fluids based on the New Range ISO VG base oils display higher VI (for the Industrial hydraulic fluid HM2 46), and higher flash points for both the industrial (HM2 46) and mobile (HV2 46) model hydraulic fluids. The pour points remain low, a possible additional benefit for the end user. CONCLUSIONS The results suggest that it is indeed possible to reproduce the key features of Group I base oils, and to formulate hydraulic fluids based on these. The new range of Group I replacement fluids thus offers a convenient way around compatibility, solubility and extensive re-formulation issues that industrial lubricant blenders otherwise must conquer when formulating in base oils other than Group I, which will gradually be less readily available in a changing base oil market. REFERENCES [1] Phadke. M., “ Synthetic Basestocks Market –Market Trends and Outlook”, Proceedings of The 2015 European Base Oils & Lubricants Summit”, Vienna, September 2015 [2] Norrby, T., Salomonsson, P., and Malm, L. “Group I Replacement Fluids – a Hydraulic Fluid Formulation and Compatibility Study”, Proceedings of the 20th International Colloquium Tribology 12-14 January 2016 : Tribology –Industrial and Automotive Lubrication. Ed. Fatemi, A., Techniche Akademie Esslingen, Germany KEYWORDS Base Stocks: Mineral Base Stocks, Lubricants: Hydraulic Fluids, Seals: Elastomeric Seals

Substitution of Group I base oils in industrial lubricants- applications in model hydraulic fluid formulationsThe 71st Annual Meeting of the STLELas Vegas, May 2016Prof. Thomas Norrby, Linda Malm & Patrik SalomonssonNynas AB, Sweden

Nynas: The Different Oil Company

12% Fuel

18% Specialty oils

70% Bitumen

96% Fuel

4% Bitumen,Specialty oilsand Lubes

Typicaloil company

What is happening in the base oil market?

The base oil market is changing rapidly!The needs of the automotive industry, driven by fuel economy legislation, is driving the major shift away from traditional Group I base oils towards Gr. II and Gr IIIThe needs of the industrial lubricant market is inconsequential to this developmentCollateral damage is caused to industrial lubricants blenders (and users), if they cannot resolve their supply issueCurrent world lubricant market, 40 M t/pa, split in:

60 % automotive lubricants40% Industrial lubricants (incl. process, MWF)

Current usage of Group I base oil70% of Group I go into industrial lubricants30% into automotive engine oils and transmission fluids

Global Usage of Group I Oils 2013 (total market approx. 17

million tons)

Source: Kline Consulting

Base oil Market in Europe

Europe has 15% of the overall global base oil capacityEurope has 25 % of the overall global Group I capacity

The global base oil oversupply increases pressure on Group I producers

Group I closures announcements Europe for 2015/ 1Q 2016:

Company Location Capacity (tpa)Shell Pernis, Netherlands 370000Total Gonfreville, France 240000Colas Dunkerque, France 290000Nynas Hamburg, Germany 165000Kuwait

petroleumRotterdam, Netherlands 250000*

*= 1Q, 2016

Evolution of the global base oil pool

51%28%

11%

1%9%

2012

Group IGroup IIGroup IIIPAONaphthenic

44%

34%

11%

1%10%

2014


26%

48%

13%

1%12%

2019 f’cast


Source. SBA Consulting

The global base oil demand scenario is here assumed to remain around 36 M mt/pa for the period

Evolution of the global base oil pool

51%28%

11%

1%9%

2012


44%

34%

11%

1%10%

2014


26%

48%

13%

1%12%

2019 f’cast


Source. SBA Consulting

The global base oil demand scenario is here assumed to remain around 36 M mt/pa for the period

The 40% Industrial slice of the pie

The widening “Solvency Gap”

Solvency is a very important property in industrial lubricant applicationsIn general, the base oil solvency affects the oil’s ability of dissolving

Additives (usually polar species)Oxidation products

A high solvency prevent varnish or deposit formation In lubricating greases, the base oil solvency affects the soap yield and the oil-soap interactionIn Metalworking fluid emulsions, the base oil solvency positively affects the emulsion stability

The widening “Viscosity Gap”

API group Light neutral Medium neutral Heavy neutral Brightstock

Group I 38% 13% 33% 16%

Group II 55% 25% 20% none

Group III 80% 20% none none

The ongoing shift in capacity will generate availability issues for heavy Solvent Neutrals and for Brightstock This is already evident from the price development of Brightstock and SN 500/600 and Group II 500 SUS (12 cSt @ 100 °C) in markets across the regions

ICIS Export price listings

How is the market going to move away from Group I?

Conversion to Group II or Group III?

Conversion to Naphthenics ?

Conversion to Group II/III – Naphthenic blends?

Nynas Oils and Group I Replacement – the new speciality base oil range

A new specialty base oil product rangeCan be widely applied in industrial lubricant formulationsNaphthenic + Paraffinic blends

Main advantages of the New Range (NR)Most similar base oil compared to Group I oilsHigh degree of flexibility in blendingWill be available over timeSuperior low temperature performance

Main challenges vs Group I base oilsLower Sulphur content Slightly higher volatilityLower flash point Slightly lower VI

Basic requirements of the New RangeThe New Range range should:

Closely match the Kinematic Viscosity (@ 40 °C) and Aniline Point of a representative reference base oil range of Solvent Neutral (SN) Group I paraffinic base oils

Allow industrial lubricant manufacturers to maintain key properties of their products by offering retained viscosity and solvency

Allow direct replacementOr with as little re-formulation and re-working of labels, PDS and other marketing material as possible (drop-in replacement)

Viscosity Range Limitations Overcome

Viscosity at 40 °C (cSt)

API Group

Group III

Group II

Group I

50 100 200 300 400 500 600 700 2500

Gr. III

Group II

Group IViscosity at 40 °C (SUS)

7 20 40 58 80 100 115 140 500

New fluid range

Heavy Naphthenics

Bright Stock

The New Range vs. SN reference base oils

The New Range (NR) vs. SN reference base oils

NR 70 SN 70 NR 100 SN 100 NR 150 SN 150 NR 300 SN 300 NR 500 SN 500 NR 600 SN 600Density (kg/m3) 0,873 0,849 0,867 0,859 0,871 0,868 0,886 0,876 0,889 0,879 0,876 0,880

FP COC (°C) 168 190 196 206 222 224 220 258 242 262 268 278

PP (°C) -27 -12 -24 -18 -24 -18 -21 -18 -21 -9 -15 -9Viscosity

@40 °C (cSt) 14 12 22 17 30 30 60 58 100 94 120 115Viscosity

@100°C (cSt) 3,1 2,9 4,2 3,7 5,0 5,2 7,3 7,8 10,2 10,7 12,6 12,2

VI 67 92 88 104 89 103 80 98 79 97 98 96Aniline Pt.

(°C ) 90 90 100 98 101 102 103 109 108 115 123 117

Sulfur (m-%) 0,02 0,2 0,01 0,2 0,04 0,2 0,02 0,2 0,03 0,3 0,02 0,3

CA 3 7 2 3 3 3 4 3 3 2 2 3

CN 42 27 36 32 35 33 36 32 36 31 30 29

CP 55 66 62 65 62 64 60 65 61 67 69 68Refractive

index 1,477 1,468 1,475 1,472 1,479 1,477 1,485 1,481 1,487 1,483 1,481 1,483

The New Range ISO VG vs. SN reference base oilsNR

ISO VG 32 SN 150NR

ISO VG 46 SN 300NR

ISO VG 68 SN 500NR ISO VG

100 SN 600Density (kg/m3) 0,866 0,868 0,872 0,876 0,874 0,879 0,875 0,880

FP COC (°C) 212 224 224 258 232 262 247 278

PP (°C) -18 -18 -18 -18 -18 -9 -21 -9Viscosity

@40 °C (cSt) 32 30 46 58 68 94 100 115Viscosity

@100°C (cSt) 5,3 5,2 6,7 7,8 8,75 10,7 11,1 12,2

VI 96 103 97 98 100 97 95 96Aniline Pt.

(°C ) 105 102 110 109 115 115 121 117

Sulfur (m-%) 0,02 0,2 0,02 0,2 0,02 0,3 0,02 0,3

CA 1 3 3 3 2 2 1 3

CN 31 33 31 32 31 31 31 29

CP 68 64 66 65 67 67 68 68Refractive

index 1,476 1,477 1,478 1,481 1,479 1,483 1,480 1,483

Properties of the New Range base oils

Low temperaturePour Point

Elastomer CompatibilitySeals and gaskets in machinery

Formulation of model hydraulic fluidsDetermination of propertiesBenchmarking vs commercial hydraulic fluids

How does a PPD additive function?

A PPD additive prevents the wax crystals from agglomerating as they form when the fluid temperature is loweredThe PPD additive consists of a polymer backbone, with paraffinic side chains that match those of the paraffin in the waxThe PPD co-crystallises with the wax in small unitsThe polymer backbone keeps the small crystalline units apartThis improved flow and filterabilityPositive synergy with naphthenic (CN) and aromatic (CA) oil components

The effect of added Pour Point Depressant (0,25 m-% PPD)by MPP ASTM D 7346

Neat

PPD@ 0.25%

-60

-50

-40

-30

-20

-10

0NR 70 NR 100 NR 150 NR 300 NR 500 NR 600 SN 150

Pour

Poi

nt (

ºC)

Elastomer Compatibility in New Range

Elastomer seal material compatibility study

The new range products, two model Hydraulic fluids and a reference Solvent Neutral Group I base oil were examined for elastomer material compatibilityFour commonly utilized seal materials, found in hydraulic systems, engines etc. were investigated:

NBR, 28% Acetonitrile (AN), Peroxide cured (BAM E008)NBR, 28 % AN, Sulfur cured (BAM E009)HNBR-1, 35% AN, Peroxide cured (BAM E020)CR, Chloroprene Rubber (BAM E021)

Elastomer seal material compatibility study

The test specimen were immersed in oil at 100 °C for 168 h (one week) evaluated according to ISO 1817 and ISO 6072

Changes were recorded for Hardness (increasing or decreasing)

“Shore A” Durometer Method (ASTM D2240 A)Mass (increasing or decreasing)

Some softening (loss of hardness) allowed by most standardsMass decrease or shrinking generally not allowed

Serious consequences for e.g. O-rings

NBR 28% AN, Sulfur cured

-10

-8

-6

-4

-2

0

2NR 70 NR 100 NR 150 NR 300 NR 500 NR 600

P15-103 HM46

P15-104 HV46

P 15-107 M46 SN 150

NBR 28% ANHardness change, %


0

1

2

3

4

5

6

7

8

9

10

NR 70 NR 100 NR 150 NR 300 NR 500 NR 600 P15-103 HM46

P15-104 HV46

P 15-107 M46

SN 150

NBR 28% ANMass change, %

Elastomer Compatibility in New Range ISO VG


-10,0

-8,0

-6,0

-4,0

-2,0

0,0

2,0NR ISO VG 32 NR ISO VG 46 NR ISO VG 68 NR ISO VG 100 HM2 46 HV2 46 HF M 46

NBR 28% ANHardness change, %


0,00

1,00

2,00

3,00

4,00

5,00

6,00

7,00

8,00

9,00

10,00

NR ISO VG 32 NR ISO VG 46 NR ISO VG 68 NR ISO VG 100 HM2 46 HV2 46 HF M 46

NBR 28% ANMass change, %

Some preliminary conclusions

All the New Range fluids display the expected and desired behaviourSeal material mass change and hardness change remains low across the NBR test seriesSeal compatibility equals that of the reference fluids

One SN 150 Group I base oilOne fully formulated industrial hydraulic fluid

This screening serves a s good indication for no-harm also in this respect

Naphthenic oils in industrial lubricants -Model Hydraulic Fluids based on New Range

Formulation of an Industrial Hydraulic Fluid

The Industrial Hydraulic fluid HM 46 is composed of Base oils (ca. 99 m-%), New Range 150 & New Range 600An additive package at 0,85 m-% (anti-oxidant, anti-wear, rust & corrosion inhibition, anti-foam) Pour Point depressant at 0,25 m-%

It was benchmarked vs a leading global industrial hydraulic fluid, in this study called M 46

Foam testing screening (ASTM D 892)

Physical Properties HM 46 (NR) vs ISO

Test Unit HM 46 ISO 111 58, HM

Method

Filterability I/II* 97/94 80/60 ISO 13357-2

Foam I @ 24 ºC ml/ml 10/0 150/0 ISO 6247:1998

Foam II @ 93 ºC ml/ml 30/0 80/0 ISO 6247:1998

Foam III @ 24 ºC ml/ml 10/0 150/0 ISO 6247:1998

Air Release min 2,0 10 ISO 9120

Demulsibility min 10 30 ISO 6614

Oil/water/emuls. ml 40/40/0 40/37/3 ISO 6614

TOST (1000 h) mg KOH/g -a ≤2 ISO 4263-1

RPVOT min 374 300a ASTM D 2272-11 method A

*= Dry (no added water), Applied Pressure 100 kPaa = SS 15 54 34:2015, Swedish Standard for Hydraulic Fluids, Level A, equal to 1000 h TOST

HM 46 (NR) vs. M 46 (Commercial)

HM 46 M 46KV @ 40 ºC 46,8 45,8KV @ 100 ºC 6,6 6,6VI 92 96Density (g/ml @ 15 ºC) 0,877 0,879Flash point (COC, ºC) 202 244Pour Point (ºC) -39 -24Nz (mg KOH/g) 0,2 0,4Water (ppm) 20 11

HM 46 (NR) vs. M 46 (Commercial)

ICP* HM 46 M 46Ca 39 34P 327 235S 849** 2472***Zn 418 259

* = Elemental Analysis by ICP ASTM D5185** = Base oil Sulfur contribution ca 300 ppm*** = Base oil Sulfur contribution significantly higher

Formulation of an Industrial Hydraulic Fluid IV

The Industrial Hydraulic fluid HM2 46 is composed of Base oils (ca. 99 m-%), New Range ISO VG 46An additive package at 0,85 m-% (anti-oxidant, anti-wear, rust & corrosion inhibition, anti-foam) Pour Point depressant at 0,25 m-%

It was benchmarked vs a leading global industrial hydraulic fluid, in this study called M 46

Physical Properties HM2 46 (New Range ISO VG) vs ISO 111 58

Test Unit HM2 46 ISO 111 58, HM

Method

Filterability I/II* 98/97 80/60 ISO 13357-2

Foam I @ 24 ºC ml/ml 0/0 150/0 ISO 6247:1998

Foam II @ 93 ºC ml/ml 0/0 80/0 ISO 6247:1998

Foam III @ 24 ºC ml/ml 0/0 150/0 ISO 6247:1998

Air Release min 3,9 10 ISO 9120

Demulsibility min 10 30 ISO 6614

Oil/water/emuls. ml 40/38/2 40/37/3 ISO 6614

TOST (1000 h) mg KOH/g -a ≤2 ISO 4263-1

RPVOT min 420 300a ASTM D 2272-11 method A

*= Dry (no added water), Applied Pressure 100 kPaa = SS 15 54 34:2015, Swedish Standard for Hydraulic Fluids, Level A, equal to 1000 h TOST

HM 46 (New Range ISO VG) vs. M 46 (Commercial)

HM2 46 M 46KV @ 40 ºC 46,2 45,8KV @ 100 ºC 6,75 6,6VI 100 96Density (g/ml @ 15 ºC) 0,873 0,879Flash point (COC, ºC) 226 244Pour Point (ºC) -39 -24Nz (mg KOH/g) 0,4 0,4Water (ppm) 43 11

HM2 46 (New Range ISO VG) vs. M 46 (Commercial)

ICP* HM2 46 M 46Ca 49 34P 333 235S 787** 2472***Zn 435 259

* = Elemental Analysis by ICP ASTM D5185** = Base oil Sulfur contribution ca 300 ppm*** = Base oil Sulfur contribution significantly higher

Miscibility Study HM 46 vs. M 46

A miscibility study is undertaken to determine the physical properties of blends of two candidate fluids – any detrimental effects?In the first study, HM 46 (NR) and M 46 (Commercial) were studiedThree blends were prepared (vol:vol)

90:1050:5010:90

The following physical propertieswere determinedFilterabilityFoamingAir releaseDemulsibility (Emulsion stability)

Miscibility study HM 46 (NR) vs. M 46 (Commercial)

Test Unit Method ISO 111 58, HM

90:10 50:50 10:90

Filterability (I)* ISO 13357-2 80 98 96 99Filterability (II)* ISO 13357-2 60 95 92 96Foam I @ 24 ºC ml/ml ASTM D 892-13 150/0 10/0 10/0 10/0Foam II @ 93 ºC ml/ml ASTM D 892-13 80/0 20/0 20/0 30/0Foam III @ 24 ºC ml/ml ASTM D 892-13 150/0 20/0 30/0 30/0Air Release min ASTM D 3427-12 13 2,5 2,8 3,1Demulsibility min ASTM D 1401-10 30 10 10 15Oil/water/emuls. ml ASTM D 1401-10 40/37/3 40/40/0 40/37/3 40/38/2

*= Dry (no added water), Applied Pressure 100 kPa

Conclusion of the Formulation & Miscibility study

1. The novel Hydraulic Fluids HM 46 (NR) & HM2 46 (NR ISO VG) display the desired and expected properties

2. The Oxidation stability result in the harsh RPVOT compares well versus demanding technical standards (e.g. Swedish Standard 15 54 34)

3. The key physical and chemical properties benchmark well vs. a common industry leading formulation (here called M 46)

4. The tested hydraulic fluids in the miscibility study were compatible: HM 46 versus M 46

5. No significant differences of the physical properties could be experimentally determined, i.e. no detrimental effects from the blending of different fluids

6. Independent testing by Rhein Chemie of model hydraulic fluid formulations based on NR ISO VG 68 confirm good wet filterability, demulsibility and corrosion protection results

Summary

The fate of the base oil industry is tied to the developments and trends of fuel refining industryThe base oil industry has been going through dramatic and fundamental changes in the last few yearsGroup II and Group III base oil production has grown at the expense of Group I productionThe rationalization of Group I production will result in a solvency and viscosity gap in the market

Naphthenic oils can fill part of that gap, e.g. in new fluid ranges

Nynas Group Head OfficeP.O. Box 10700SE-121 29 StockholmSweden

Tel. +46-8-602 12 00Fax +46-8-91 34 27

[email protected]

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