borja coto isup2008

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ABSORTION OF BIOLUBRICANT OXIDATIONABSORTION OF BIOLUBRICANT OXIDATION

PRODUCTS IN NANOPOROUS MATERIALPRODUCTS IN NANOPOROUS MATERIAL

B. Cot o, A. Marcaide, A. Aranzabe, C. Zubizarreta

Fundación Tekniker, Avda. Otaola 20, Eibar, Spain

[email protected]

www.tekniker.es



Outline

Frame of t he work

Met hodology

Absor t ion simulat ions of oxidat ion products

Molecular Dynamics simulat ions

Fut ure Work



Frame of t he work

To develop an eco-indicatorbased on biodegradability andtoxicity measurements to fill

the gap for a reliableenvironmental impact

evaluation of lubricants

To promote the use crudeglycerine obtained from usedvegetable oil FAME process

(biodiesel production)transforming it from a no-valueby-product to an added-value

renewable raw material.

To obtain polyglycerol esterderivates from purified crude

glycerine for compressorapplications

To replace harmful antioxidantcompressor oil additives by

means the design of a newcompressor device based on amolecular sieve for a selectivetrapping of oxidation products

The aim of t he project is

the optim isation of t he new

sustainable lif e cycle of an environm entally f riendly and safe compressor oil

6th Framework Programe. I. P.

Soilcy ( 515848)



Biolubricants

Biolubricants

Additives

Improvedperformance

Enviromentally

Unfrendly

Additives

??????

Biolubricants

Additives

Improvedperformance

Additives

Enviromentally

Unfrendly

??????

Biolubricants

Additives

Improvedperformance

Additives



Molecular Sieve

Biolubricants

Improvedperformance

Enviromentally

Unfrendly

???

Molecular

Selective

Trap

Additives



Compressor oil application

Model l ing can help t o select proper mat er ials

Sorpt ive behaviour of t he oxidat ion product s f rom a a t r imet hylolpropane (TMP) est er base oil

inside a nanoporous mat er ial Compressor working condi t ions of pressure and

temperature



Computational methods

Molecular Dynamics

Simulations

Monte Carlo Absortion

Simulations

Minimun Energy

Configuration Structures

At omist ic model l ing aproach

Forcefield based calcultions

Each at om has a pot ent ial energy associat ed t o surrounding

at oms Forcef ields contains paramet ers

for t he energy expresions



Mat er ials St udio and Compass Forcefield

Mat er ials St udio 4.2

COMPASS Forcef ield

Widely Val idat ed

13 Terms

Bond and non bonding

interactions



Molecules and Sorbent

Cromatographic Analysis 2-Decanone2-

UndecenalDecanoic

Acid

Nonanoic

AcidDecanal NonanalNanoporous Material

Oxidation Products Molecules

9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

s e ñ a l

c r o m a t o g r a f i c a ( U . A . )

GCM.chrom. TMP oleate 120h





Tiempo de retención (min)

Pico 1

Pico 2

Pico 3

Pico 4

Pico 5

Pico 6



Energy minimizat ion

242,810209,81011,510Decanoic Acid

241,840205,12012,3202-Undecenal

227,430194,09011,546Decanal

226,800193,50011,5052-Decanone

215,570183,47010,197Nonanoic Acid

208,330175,66010,122Nonanal

Surface Area ( Ǻ2)Occupied Volume ( Ǻ

3)Length ( Ǻ)Molecule

Connolly Surfaces:Occupied Volume and

Surface Area2-Undecenal

Geometry

optimization

·Steepest Descents

·Conjugated Gradient

Energy

Minimization



Comput at ional Uni t Cel l

Free Pore Volume:

3.4 nm3

• (100) Surface

• Vacuum Slab: 2D Boundary

Condition• Computational Cell:

a = 2 nm; b = 1.33 nm; c = 8 nm

• Geometry optimization• Connolly Surfaces

• Occupied Volume = 7.23 nm3

• Surface area = 2.89 nm3

• Free Volume = 14.05 nm3



Mont e Car lo Met hods

Grand Canonical ensamble

Syst em can exchange energy and part icles wi t h a surrounding reservoir

Resorvoir is described by t emperature and fugacit ies so i t is not necessary to simulat e i t in a explici t way

Mont e Car lo Biased Method

Fixed pressure simulat ions

Trial configurations are generated with a probability

Acceptance probabil i t y depends on t he energy of t he

system congigurat ion generated Torsional degrees of f reedom are taken into account



Absort ion Isotherms

• Sorpt ion was studied for T andP from room condit ions up tothe working condit ions of a

compressor for each molecule

• Sorpt ion Isotherms werecalculated

1,173-525,93717,21518,000Nonanal

1,073-545,81815,74417,000Decanal

1,066-1005,99215,64117,000Nonanoic Acid

0,998-988,18914,65515,000Decanoic Acid

0,990-591,86814,52716,0002-Decanona

0,889-973,82513,04814,0002-Undecenal

Maximun Density

(molecules/nm3)

Average Energy

(kcal/mol)

Average LoadMaximun

Load

Molecule

298 K

1 Atm

2-decanone sorption Isotherms

10

11

12

13

14

15

16

17

18

19

20

0 1 2 3 4 5 6 7 8 9 10 11

P (Atm)

N u m b e r o f a b s o r b e d m o l e c u l e s

2-Decanona 298 K

2-Decanona 358 K

2DEcanona 378 K



Sorpt ion isobares, Isost er ic heat s and prefer red absor t ion si t es

Sorption Isobares 10 atm

12

13

14

15

16

17

18

19

20

21

278 298 318 338 358 378

T (K)

N u m

b e r o f a b s o

r b e d

m

o l e c u l e s

Nonanal

Decanal

Nonanoic Acid

Decanoic Acid

2-Decanone

2- Undecenal

Isosteric heats

25

30

35

40

45

50

0 2 4 6 8 10 12

P (Atm)

I s o s t e r i c

h e a t ( k c a l / m o l )

Decanoic Acid 298 K

Decanoic acid 358 K

Decanoic Acid 378 K

Density of absorption profiles of

nonanal at 358 K 10 atm



Fixed Pressure Calculat ions

• Fixed Pressure calculations

allow to obtain the

minimun energy

configurations for givenconditions

• Detailed view of the

system is available to

study specific interationsand conformational

analysis



Molecular Dynamics Simulat ions

Molecular Dynamics

Simulations

Minimun Energy


Monte Carlo Absortion

Simulations

Minimun Energy




Molecular Dynamics

Newt on’ s equat ion is solved for a given pot ent ial (COMPASS)

Verlet integration

1.5 ns simulat ions St ep 2 f s.

NPT Ensemble

Berendsen Thermost at Berendsen Barost at

• Atomic Trajectories

• Dinamical Behaviour



Molecular Dynamics

Nonanal 298 K 1 atm Nonanal 358 K 10 atm



Traj ect or ies Analysis

Nonanal Mean Square Displacement

0

100

200

300

400

500

600

700

0 200 400 600 800 1000 1200 1400 1600

Time (ps)

M e a n

S q u a r e D i s p l a c e m

e n t ( Å 2 )

T = 298 K; P = 1 Atm

T = 358 K; P = 5 Atm

T = 358 K; P = 10 Atm

Diffusion Coefficient

6,79·10-45,84·10-44,12·10-4Diffusivity(nm2 s-1)

T=358K; P=10atmT=358 K; P=5atmT=298 K; P=1atmNonanal

Conformational analysis



Work in Progress & Fut ure Work

Molecular Dynamics Simulat ions Fut ure Work

Absort ion simulat ions wit h mixtures of molecules

Dif ferent mat erials

Compare wit h experiment s

Funct ional izat ion and/ or doping of t he nanopororus mat erials



Summary

Molecular Model l ing simulat ions have been carr ied out t o

st udy t he absort ion of oxidat ion producs of an TMP est er oil in a porous nanomat er ial f or compressor applicat ions Geomet ry opt imizat ion was done t o obtain lengt hs and

volumes f or t he modelled syst em MC simulat ions were per formed t o st udy t he sorpt ion

behaviour of t he oxidat ion product s MD calculat ions were per formed in order t o st udy t he

dynamic behaviour of t he syst em

Next st eps wi l l involve ot her sorbent nanomat er ials and comparison with experimental results



Acknowledgement s

U.E. - 6t h FP –IP Soi lcy (Cont ract 515848 ) Basque Count ry Government . Saiot ek

Program



THANK YOU FOR YOUR ATTENTION

borja coto isup2008

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