Long-term performance of oils for stationary gas engines ... · AC²T research GmbH,...

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AC²T research GmbH, Viktor-Kaplan-Straße 2, 2700 Wiener Neustadt, Austria

Tel. +43 (0) 2622 / 816 00-210, Fax +43 (0) 2622 / 816 00-99, e-mail: [email protected], web: www.ac2t.at

Long-term performance of oils for stationary gas engines

determined by lab-based artificial ageing as economic means

Need for novel artificial ageing methods… is based on general but significant requirements:

Knowledge about the impact of fuel in the oilEconomically short test durationPeriodical oil condition monitoring

… but not yet provided by standardized ageing procedures, e.g.,ASTM D 4871 – 06ASTM D 7079-09CEC L-48-A-00

A strong connection to the real-life conditions is required!

IntroductionGrowing interest in renewable energy due to:

Environmental concerns, e.g. global warmingAwareness of limited fossil fuel resources Reduction of dependence on oil imports and on increasing oil prices

Increasing use of bio-fuels from renewable materials

But trends towards high-power engines and the use of bio-fuels result in:Accelerated oil degradation and therefore shortened oil drain intervalsAcidification with unforeseen corrosion

Experimental set-upThe oil sample is kept at a selected temperature in a closed ageing reactor *). By circulation of the oil using a pump the oil is brought in contact with dried air. The air can be mixed with gaseous contaminations prior to supply to the ageing reactor. Over an outlet in the oil cycle continuous monitoring and/or automatic sampling is done.

Artificial ageing was carried out under following parameters:

Oil temperature: 160 °CAir flow: 10 L/hOil sampling: every 10 hTest duration with air: 120 hTest duration with air containing contamination: 60 hAmount of sample: 500 mL

Various oil parameters were monitored. The most important are:

Oxidation by FTIR in [Absorbance/cm]Total Base Number (TBN)Neutralization Number (NN)

Results and discussionArtificial ageing was carried out with a commonly available gas engine oil with and without contamination. The visual appearance (Fig. 1) of the oil after different artificial ageing periods clearly states the strong impact of contaminations on oil deterioration.

ConclusionsThe simulation of engine processes using the novel lab-based artificial ageing method has enabled …

good correlation between artificially aged engine oils and oils from the field according to conventional oil parameters,

differentiation in performance between different oil formulations,

understanding of ageing mechanisms by interactions with biogas, and

valuable input for the formulation of engine oils.

AcknowledgementThis work was funded by the "Austrian Kplus-Program" (governmental funding program for pre-competitive research) via the Austrian Research Promotion Agency

(FFG) and the Province of Niederösterreich (TecNet Capital GmbH) and has been carried out within the "Austrian Center of Competence for Tribology“.

[Faninger, G.: Renewable Energy Resources and Technologies in Austria – State of the art report 2005. Berichte aus Energie- und Umweltforschung 26/2006]

Fig. 2: Comparison of different artificial ageing conditions with field

conditions (a) Total Base Number and (b) Neutralization Number

The results were compared to oil samples from a gas engine in the field lubricated by the same oil.Fig. 2 shows the comparison of the most important oil parameters, namely total base number and neutralization number according to the respective oxidation values of artificially and naturally aged oils.

Fig. 1: Visual appearance of artificially aged oil samples

(a) with air and (b) with gaseous contamination

(a)

(b)

fresh 1d 2d 3d 4d

0

2

4

6

8

10

0 5 10 15 20

Oxidation [Abs/cm]

TB

N [

mg

KO

H/g

]

0

1

2

3

4

5

6

0 5 10 15 20

Oxidation [Abs/cm]

NN

[m

g K

OH

/g]

(a)

(b)

Ageing reactor

Pump Continuouscondition

monitoringand/or

automaticsampling

*) patentapplied

Ageing with air

Ageing with gas. contamination

Real engine filling 1

Real engine filling 2

Development of a novel lab-based artificial ageing method for …

rapid evaluation of the impact of biogas on the performance of selected gas engine oils, and

close-to-reality oil deterioration.

Charlotte Bessera*, Christoph Schneidhofera, Nicole Dörra, Franz Novotny-Farkasb, Günter Allmaierc

aAustrian Center of Competence for Tribology – AC²T research GmbH, Wiener Neustadt, AustriabOMV Refining & Marketing GmbH, Vienna, Austria

cInstitute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria*corresponding author: Charlotte Besser, e-mail: [email protected]

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AC²T research GmbH, Viktor-Kaplan-Straße 2, 2700 Wiener Neustadt, Austria


AcknowledgementThis work was funded by the “European Commission" within the FP7 programme Marie Curie “Initial Training Network MINILUBES (216011-2)” and has been

carried out within the "Austrian Center of Competence for Tribology“.

Degradation of ionic liquid based lubricantsstudied by mass spectrometry

a Austrian Center of Competence for Tribology – AC²T research GmbH, Wiener Neustadt, Austriab Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria

*corresponding author: Lucia Pisarova, e-mail: [email protected]

Lucia Pisarovaa,b*, Christoph Gablera, Nicole Dörra, Ernst Pittenauerb, Günter Allmaierb

Introduction

Ionic liquids (IL) are object of research for their use in

lubricants. Compounds with both long-term performance and environmentally benign behaviour have to be made available to comply with the demand for sustainability.

For this reason, the chemical structure of a IL based on short chain ammonium bis(trifluoromethylsulfonyl)imide (NTF2) was modified step by step. Thermo-oxidative stability was investigated using high end mass spectrometry (MS) to elucidate the ageing behaviour on the molecular level.

Analysis of artificially aged IL

Visual appearance (colour and transparency)

Condition monitoring by Fourier Transformation Infrared Spectrometry with Attenuated Total Reflection (FTIR-ATR)

MS analysis by Laser Desorption Ionization - ReflectronTime-of-Flight (LDI-RTOF) MS and MS/MS (TOF/RTOF)

Conclusions

Low molecular IL were successfully examined by LDI-RTOF-MS and MS/MS (CID) for structural elucidation.

Methylated choline of IL3 was identified as degradation product under all artificial ageing conditions.

In contrast, choline moiety in IL2 remained stable under all artificial ageing conditions.

The importance to consider IL moieties together and not separately has been confirmed.

LDI-MS and MS/MS turned out as valuable technique to investigate lubricants applied for long-term lubrication.

LDI-RTOF mass spectrometric analysis

IL1 and IL2 which contain the NTF2 anion show no degradation

under all artificial ageing conditions.

Choline (m/z 104) degradation of IL3 under all examined conditions

by formation of (2-methoxy-ethyl)-trimethyl-ammonium (m/z 118).

Fig. 3: IL3 FTIR spectra, fresh, aged, 190°C

Fig. 6: Mass spectrum of artificially aged IL3, no metal immersed,190°C

Fig. 5: Mass spectrum of artificially aged IL2, no metal immersed,190°C

Reference

Zabet-Moghaddam, et al.: Matrix-assisted laser desorption/ ionization mass spectrometry

for the characterization of ionic liquids and the analysis of amino acids, peptides and

proteins in ionic liquids. J. Mass Spectrom. 2004, 24, 1494.

Results and Discussion

Experimental

Fig. 8: CID fragmentation tree of methylated choline

Fig. 7: Artificially aged IL3, MS/MS (CID) of precursor ion m/z 118

Visual appearance

Optical changes do not necessarily indicate structural changes of IL

Artificial ageing procedure

Parameters

�Temperature

�Air (O2)

�Water

�Metals immersed

IL1

IL2

IL3

collision induced dissociation (CID) for the identification of ions originating from the precursor ion m/z 118 (methylated choline)

proposed fragmentation for the structural confirmation of methylated choline (m/z 118) as precursor ion exhibiting structures of the resulting product ions

Ionic liquids selected

FTIR-ATR ionic liquid monitoring

comparison of FTIR spectra of fresh and aged IL

no valuable information on

structural changes gained

so far not directly applicable

for IL condition monitoring

Hydrophobic IL with good thermal-oxidative stability

Hydroxyl group to give biologically degradable structure, namely choline

NTF2 replaced by environmentally more benign methanesulfonate

Choline Methylatedcholine

Fig. 1: Small scale artificial ageing

sampling

sampling

7 days 14 days 21 days

150°C

175°C

190°C

Fig. 2: Optical appearance during artificial ageing at atmosphere

150°C 175°C 190°C

IL1Butyl-trimethyl-

ammonium NTF2

IL2Choline

NTF2

IL3Choline

methanesulfonate

IL

code

Sta

rt Access to air Name

Optical changes

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bundance

N+

CH3

CH3

CH3OCH

3

M+ (m/z 118)

N+

CH2CH2

CCH2

O

H+

+

CH3

O

+

N+

CH2

CH3

CH3

CH3

O CH2

CH2

+N

+

CH3

CH3

CH3

H

N+

CH3

CH3

CH3

CH3

N+

CH3

CH3

CH3

CH2

m/z 42

m/z 43

m/z 43

m/z 58

m/z 59m/z 60

m/z 74

m/z 86

m/z 102

N+

CH3

CH3

CH3

O

� N+

CH3

CH3

CH3OCH

3

M+ (m/z 118)

N+

CH2

CH2

CCH2

O

H+

+

CH3

O

+

N+

CH2

CH3

CH3

CH3

O CH2

CH2

+N

+

CH3

CH3

CH3

H

N+

CH3

CH3

CH3

CH3

N+

CH3

CH3

CH3

CH2

m/z 42

m/z 43

m/z 43

m/z 58

m/z 59m/z 60

m/z 74

m/z 86

m/z 102

N+

CH3

CH3

CH3

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ANALYSIS OF ANTIOXIDANTS APPLIED IN LUBRICANTS BY

ESI- AND AP-MALDI ION TRAP MSn (n = 1 - 3)

Alexander Kassler1,2, Ernst Pittenauer1, Nicole Doerr2 and Guenter Allmaier1

1Vienna University of Technology, Institute of Chemical Technologies and Analytics, Vienna, Austria2Austrian Center of Competence for Tribology (AC²T research GmbH), Wr. Neustadt, Austria

IntroductionAn important group of additives for lubricants are antioxidants applied for

stabilization and therefore improving oil change intervals considerably.

Important antioxidants constitute either sterically hindered phenolic compounds or

aromatic amines [1]. Investigation of both groups is necessary because phenols

and amines behave differently. Amines quench radical oxidation intermediates

very fast whereas slower reacting phenols regenerate the amines. Only in the

proper combination of these compounds an optimal stabilization of the lubricant

takes place. For first mass spectrometric experiments 22 different compounds

were selected for detailed mass spectrometric investigation.

ExperimentalAll analytes were measured by means of positive- and/or negative-ion ESI- and

AP-MALDI IT MS (Esquire 3000plus and HCTplus, respectively; Bruker Daltonics,

Bremen, Germany). For ESI measurements the samples were dissolved in

methanol: 2-propanol = 1: 1 (v/v). For the verification of molecular ions of aromatic

amines samples were also analyzed in methanol: water = 1: 1 (v/v) containing 0.1

% acetic acid. For AP-MALDI-MS -cyano-4-hydroxy cinnamic acid (CHCA) was

used as matrix. Samples were prepared either on gold-, TiN-, micro diamond-

covered targets or on SS targets (polished, sand-blasted). The elemental com-

position of certain selected ions was determined by accurate mass measurements

utilizing an ESI/AP-MALDI LTQ Orbitrap MS (Thermo, Bremen, Germany).

AcknowledgmentsThis work was funded by the "Austrian Kplus-Program" (governmental funding program for pre-

competitive research) via the Austrian Research Promotion Agency (FFG), the TecNet Capital

GmbH (Province of Lower Austria) and has been carried out within the AC²T research GmbH.

The AP-MALDI IT MS was provided by the Vienna University of Technology to G. Allmaier.

Research Research groupgroup biobio--

and polymer and polymer analysisanalysis

References1. Migdal, C. A, in Lubricant Additives: Chemistry and Application (Rudnick, L. R., Ed., CRC

Press, Boca Raton, Florida) 1-28 (2003).

Results and Discussion

OH

O

O

16

(A) OH

N

(B)

ESI-Ion Trap

All 22 selected antioxidants showed good results in positive-, whereas only some

of them could be detected in negative-ion mode.

In a water-free solution some aromatic amines like N,N‘-di-sec-butyl-p-

phenylenediamine (Fig. 1) primarily formed a M+• radical ion and relatively low

abundant [M+H]+- and [M+Na]+-ions (Fig. 2A). Only by changing the solvent to

methanol: water = 1: 1 containing 0.1% acetic acid the radical molecular ion could

be suppressed by favouring the [M+H]+-ion (Fig. 2B).

Data interpretation was performed by exporting mass spectra and CID spectra

into MassFrontier 5.0 (HighChem, Bratislava, Slovac Republic) for creating

spectral trees from MS1- up to MS3-spectra, which were created manually by

using the features of the Spectral Library (Fig. 3). Interpretation of CID spectra

was done by using tools of Fragmentation Library. With these features

fragmentation trees for all measured precursor ions of the antioxidants were

developed and saved to enhance the Library for future use (Fig. 4).

AP-MALDI-Ion Trap

In positive-ion AP-MALDI MS all aromatic amines and the phenols with a second

functional group were successfully desorbed/ionized and often formed unusual

molecular ions as M+• and [M-H]+. Desorption/ionization of simple phenols as

butylated hydroxytoluene was not feasible under the applied conditions. None of

the analytes could be measured in negative-ion AP-MALDI MS mode.

In addition, the effects of different target surfaces on the intensity of the molecular

ions of octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and 2,6-di-tert-

butyl-4-(dimethylamino-methyl) phenol (Fig. 5) were investigated. Three spots of

each analyte were prepared on gold-, titan nitride- (TiN), micro diamond-covered

targets and on two different SS ones (polished, sand blasted) (Fig. 6). On the

plane gold-, TiN- and polished SS surfaces sample preparations give distinct

small spots (1 µl gave ø 3-4 mm). Solutions deposited on rough micro diamond-

covered and sand-blasted SS surfaces show the tendency to spread across a

larger area (1 µl gave ø 5-8 mm) (Fig. 6D-F).

First of all, the results show very little effect related to the target material on the

peak ratio of the analyte molecular ions with the exception of micro diamond-

covered target (Fig. 7). Because of the large area of the analyte solution,

crystallization was uneven and also the concentration per area was rather low at

rough surfaces. So, these mass spectra exhibited relatively low intensity and

reproducibility. Standard deviations of the measurements were up to half of the

average intensity. Again, the micro diamond-surface yields differing results with

respect to intensity and types of different molecular ions formed (Fig. 7B). Finally,

comparison of the two analytes does not show any trend for a target material

being more suitable for measuring antioxidants then the others. Hence it will be

necessary to find the optimal target for each antioxidant.

ConclusionsBased on the chemical structures of the antioxidants investigated, practically

all compounds could be characterized by positive-ion ESI and AP-MALDI MS.

Only a few compounds could be analyzed by negative-ion ESI MS in the

selected solvent system and none by negative-ion AP-MALDI MS with the

matrix CHCA.

The chemical structures are the main reason for the formation of seldom

observed molecular ions as M+• radical cations and even [M-H]+-ions which

are stabilized through the aromatic ring (some MALDI matrices exhibit a

similar behaviour).

Utilizing different target materials are influencing the signal intensity in AP-

MALDI MS. Therefore varying results of selected antioxidants on different

target surfaces indicate that for individual analyte molecules appropriate target

surfaces have to be found.

Fig. 5 Chemical structures of octadecyl-3-(3,5-di-tert-

butyl-4-hydroxyphenyl) propionat [MWt. monoisotopic

530.470 calculated] (A), 2,6-di-tert-butyl-4-(dimethyl-

amino-methyl) phenole [MWt. monoisotopic 263.225

calculated] (B).

Fig. 2 Positive-ion ESI-ion trap mass spectra of the antioxidants N,N‘-di-sec-butyl-p-phenylenediamine in

methanol : 2-propanol = 1: 1 (v/v) (A) and in methanol : water = 1: 1 (v/v) containing 0.1% acetic acid (B).

Fig. 3 Spectral tree of thiodiethylene bis-(3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate) in Spectral Library based

on positive-ion ESI-MSn (n = 1 - 3) of the [M+H]+-, [M+NH4]+-, [M+Na]+- and [M+K]+- precursor ions.

MS3

MS2

MS2

O

O

OH

SO

O

OH

m/z 642.395

O

O

OH

SO

O

OH

NH4+

m/z 660.429

H+

O

O

OH

S

m/z 365.214

O

O

OH

S

H+

m/z 309.152

H+

O

O

OH

m/z 249.149

O

O

OH

H+

m/z 193.086

H+

O

O

m/z 175.075

+NH4+

+H+, rHR

MS2

rHC MS3

MS3

MS3

Fig. 4 Fragmentation tree of the [M+Na]+- precursor ion of thiodiethylene bis-(3-(3,5-di-t-butyl-4-hydroxyphenyl)-

propionate) in Fragmentation Library based on positive-ion ESI-MSn (n=1-3). Shown m/z-values are based on

theoretical calculations.

Fig. 1 Chemical structures of N,N‘-di-sec-butyl-p-phenylenediamine [MWt. monoisotopic 220.194 calculated] (A)and thiodiethylene bis-(3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate) [MWt. monoisotopic 642.395 calculated] (B).

OH

O

O

S

OH

O

O

NH

NH

(B)(A)

60 80 100 120 140 160 180 200 220 240 m/z

RE

LA

TIV

E A

BU

ND

AN

CE

(B) Positive-ion ESI, 0.1% acetic acid

(A) Positive-ion ESI, water-free

[M+H]+

221.1

M+•

220.1

M+•

220.1

[M+Na]+

243.1

[M+H]+

221.1

Fig. 6 Different targets used in positive-ion AP-MALDI-

ion trap MS: gold-covered target (A), titan nitride-

covered target (B), polished SS target (C), different

sand-blasted SS target with one half more (D) and the

other half less rough-textured (E) and micro diamond-

covered target (F).

(A)

(C)

(B)

(E)(D)

(F)

Fig. 7 Comparison of the influence of the target materials expressed by the intensity of the molecular ions observed

([M-H]+, M+• and [M+H]+) by positive ion AP-MALDI-IT MS. Diagrams are representing an average value of 3

individual measurements (3 preparations in parallel on the same day) of octadecyl-3-(3,5-di-t-butyl-4-

hydroxyphenyl) propionat (A) and 2,6-di-t-butyl-4-(dimethylamino-methyl) phenole (B). Additionally, elemental

composition of molecular ions were determined by an AP-MALDI LTQ Orbitrap MS [R = 30.000, FWHM] (C),respectively (D).

261 262 263 264 265 266m/z

0

10

20

30

40

50

60

70

80

90

100

Rela

tive A

bund

ance

[M+H]+

264.23273

[M-H]+

262.21732

Isotopic Peak

C1613CH30ON

265.23611

Isotopic Peak

C1613CH28ON

263.22067

(D)(B)

528 529 530 531 532 533m/z

0

10

20

30

40

50

60

70

80

90

100

Rela

tive A

bund

ance

M+•

530.46960[M-H]+

529.46191

Isotopic Peak

C3413CH62O3

531.47345

(C)(A)

IONICRAIL

Systemische Schienenkopf-Konditionierung durch alternative Konditioniermittel, wie Ionische Flüssigkeiten,

und Aufbringungsapparaturen

KonsortiumPartner 1: AC²T research GmbH (Projektleitung)

Kontakt: [email protected] 2: Wiener Linien GmbH & Co KG

Kontakt: [email protected] 3: HY-POWER Produktions- und Handels-GmbH

Kontakt: [email protected] 4: Büro für angewandte Mechanik und

Mathematik - Dr. Mittermayr Scientific Consulting GmbH (BAMM)Kontakt: [email protected]

Partner 5: psiA-Consult Umweltforschung und Engineering GmbH

Kontakt: [email protected] 6: Technische Universität Wien

Institut für Angewandte SynthesechemieKontakt: [email protected] 7: Technische Universität Wien

Institut für Verkehrswissenschaften, Forschungsbereich für Eisenbahnwesen, Verkehrswirtschaft und Seilbahnen

Kontakt: [email protected]

03.2009 - 02.2011 Projektart: IF

Ziel / InhalteEinstellung der Traktion zwischen Rad und Schiene

Ganzheitliche Erfassung des Tribosystems Rad-Schienenkopf-Konditioniermittel

Formulierung und Evaluierung alternativer Konditioniermittelauf Basis ionischer Flüssigkeiten

Optimierte Gestaltung einer automatischen ortsfestenKonditioniermittel-Aufbringung

Ionische Flüssigkeiten sind organische Salze mit

niedrigem Schmelzpunkt

(Zwischen)ErgebnisseKandidaten aus ionischen Flüssigkeiten

für die Erprobung in Feldversuchen erarbeitet

Theoretische (mathematische Simulation der mechanischenund thermischen Gegebenheiten) und

experimentelle (tribologischer Modellkontakt) Abbildung des Rad-Schiene-Kontakts

MilestonesAnforderungsprofil (Simulation, Erfahrung) an alternativer

Konditioniermittel erstellt

Definition, Formulierung und Untersuchungen alternativer Konditioniermittel im Labormaßstab abgeschlossen

Abstimmung zwischen Konditioniermittel und Aufbringungsapparatur erfolgt

Alternative Konditioniermittel und Aufbringungsapparaturin Feldversuchen evaluiert

KooperationenfractINSPECT, sysBahnLärm, UI2P InfraIntegrity,

UV wave, WDS Rille

Lessons LearnedStrukturanpassung ionischer Flüssigkeiten an die

Anforderungen eines alternativen Konditionierungsmittelsbzgl. biologischer Aktivität, Korrosivität, tribologischer

Eigenschaften

Erarbeitung geeigneter tribometrischer Messmethoden

Optimierungsansätze zur Konditioniermittel-Aufbringung

AusblickAusbau des interdisziplinären und intersektoralen Konsortiums auf

nationaler und internationaler EbeneÜbertragung der Erkenntnisse auf die Vollbahn

Verfeinerung der Formulierung und Kommerzialisierung alternativer Konditioniermittel

Geschlossen Geschlossen Offen

Pur Wasser gesättigt Pur

Start

150°C

175°C

Optische Veränderungen und Korrosionsverhalten einer ionischen Flüssigkeit gegenüber Schienen-Probekörper

Innere (von Mises) Spannungen in einem Rad-Schiene-Kontakt

N+

N

P

F

F

F

F

F

F

0

200

400

600

800

1000

1200

1400

1600

Fe

[p

pm

]

150 175 190

Temperatur [°C]

Long-term performance of oils for stationary gas engines ... · AC²T research GmbH,...

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