Structure of premixed flat burner-stabilized H2/O2/Ar flame doped with Ti(OC3H7)4 at 1 atm.

A. G. Shmakov1, O. P. Korobeinichev1, D. A. Knyazkov1, A. A. Paletsky1, R. A. Maksutov2, I. E. Gerasimov2, S. A. Yakimov1, T. A. Bolshova1

1Institute of chemical kinetics and combustion, Novosibirsk, Russia2Novosibirsk state university, Novosibirsk, Russia

7th INTERNATIONAL SEMINAR ON FLAME STRUCTURE and

FIRST YOUNG RESEARCHERS’ SCHOOL ON FLAME STUDY Novosibirsk, Russia, July 11-19, 2011

IntroductionApplication of nanocrystaline

mesoporous TiO2 films :

• Dye sensitized solar cells, DSSC

• Sensors for gas analyzers

Traditional approaches for TiO2 films fabrication:

• sol-gel method

• screen printing

• spray deposition

• doctor blading

New approach for TiO2 films fabrication by one step in premixed lean flame C2H4/O2/Ar +

0.030.10% Ti(OC3H7)4 •E.D. Tolmachoff, A.D. Abid, D.J. Phares, C.S. Campbell, H. Wang, Proceedings of the Combustion Institute 32 (2009) 1839–1845

•S. Memarzadeh, E.D. Tolmachoff, D.J. Phares and H. Wang, Proc. Combust. Inst. 33 (2011) 1917-1924

OO

O

Ti

O

CH

CH3

CH3

CH

CH3

CH3

CH

CH3 CH3

CH

CH3CH3

OO

O

Ti

O

CH

CH3

CH3

CH

CH3

CH3

CH

CH3 CH3

CH

CH3CH3

!

Chemistry and kinetics of reactions of Ti-containing compounds in flames:

• TiCl4 – Pratsinis S.E. et al, Aerosol Sci. 2002, 33, 17. – Kraft M. et al, Combust. Flame 2009,156, 1764.

• Ti(OC3H7)4 – Okuyama K. et al, A.I.Ch.E. 1990 Journal 36, 409.

Ti(OC3H7)4(gas)TiO2+4C3H6+2H2O k=3.96105exp(-8479.7/T)

• the detailed mechanism and kinetics of TTIP thermal decomposition are practically unknown.

Research Objectives

•to study of the structure of premixed flame

stabilized on a flat burner

• H2/O2/Ar (12.9%/14.4%/72.7%) + 0.1% Ti(OC3H7)4, = 0.45

• Numerical modeling of flame structure

using one-step reaction for Ti(OC3H7)4

thermal decomposition.

6,7 мм

Skimmer

MS-7302

10torr

-3

5 10xtorr

-8

3 10xtorr

-5

Ion pump,400 L/s

Turbomolecular pump, 500 L/s

Turbomolecular pump, 500 L/s

Diffusion pump, 1100 L/s

“Sonic”probe

Disk chopper

Liquid-nitrogen trap

Flame

Burner with burner positioning mechanism

EXPERIMENTAL APPROACH Measurement of Flame Structure

Premixed laminar flame was stabilized on the flat burner. The profiles of

concentration of flame species were measured using MBMS setup:

EXPERIMENTAL APPROACHAlumina ceramic probe (sonic probe) on an enlarged

scale

The probe was clogged by TiO2 particles for 30-50 s of experiment and demanded cleaning.

Perforated disk

Ar

Ti(OC3H7)4

Thermostat 900С

Thermostat 900С

Steel balls

Combustible mixture

Flame

EXPERIMENTAL APPROACH

Probe

Combustible mixture

( = 0,45 )

H2/O2/Ar (13/14.5/72.5 %)+ 0,12% Ti(OC3H7)4

Species m/z

H22

O232

H2O 18

Ti(OC3H7)4269

TiO280

TiO 64

HTiO 65

HTiO281

Ti2O3144

Ti 48

TiH 49

Identified flame species

• Hydrogen combustion mechanismKonnov A.A. Combustion and Flame, V. 152, pp. 507–528, (2008)

• Gas-phase reaction for thermal decomposition of Ti(OC3H7)4:

Ti(OC3H7)4(gas)TiO2+4C3H6+2H2O k=3.96105exp(-8479.7/T)

Okuyama K. et al, A.I.Ch.E. Journal, 36, 409–419 (1990)

• Thermochemistry for Ti(OC3H7)4 и TiO2 http://webbook.nist.gov/cgi/cbook.cgi

• PREMIX and CHEMKIN codes (Sandia National Laboratory, USA)

MODELING

Height above burner, mm

0 1 2 3 4 5

Mol

e fr

actio

n

0.00

0.05

0.10

0.15

0.200.600.700.800.901.00

Spatial variations of H2O, O2, H2 mole fraction in H2/O2/N2 flame doped with 0.1% Ti(OC3H7)4 stabilized on a flat burner.

O2

H2O

Ar

H2

Results and Discussion

m/z=269

Height above burner, mm

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Rel

ativ

e si

gnal

inte

nsity

0.0

0.2

0.4

0.6

0.8

1.0

1.2

TT

IP m

ole

frac

tion

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.0012

0.0014

0.0016

Results and DiscussionSpatial variations of mass peak intensity m/z 269 and Ti(OC3H7)4

mole fraction in H2/O2/N2 flame.

Symbols – experiment, line - modeling

Spatial variations of mass peak intensity m/z=80 (TiO2) and TiO2 mole fraction in H2/O2/N2 flame.

0

0.01

0.02

0.03

0.04

0.05

0.06

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Height above burner, mm

Rela

tive

sign

al in

tens

ity

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0.0016

TiO

2 m

ole

frac

tion

Results and Discussion

Symbols – experiment, line - modeling

Spatial variations of mass peak intensity m/z=48 (Ti)

in H2/O2/N2 flame.

Results and Discussion

0

0,005

0,01

0,015

0,02

0,025

0,03

0,035

0,04

0,045

0 1 2 3 4 5 6

Height above burner, mm

Re

lativ

e s

ign

al i

nte

nsi

ty

Symbols – experiment, line - spline

0

0,01

0,02

0,03

0,04

0,05

0,06

0 1 2 3 4 5 6

Height above burner, mm

Re

lativ

e s

ign

al i

nte

nsi

ty

Spatial variations of mass peak intensity m/z=49 (TiH)in H2/O2/N2 flame.

Results and Discussion

Symbols – experiment, line - spline

Spatial variations of mass peak intensity m/z=64 (TiO)in H2/O2/N2 flame.

Results and Discussion

Height above burner, mm

0 1 2 3 4

Rel

ativ

e si

gnal

inte

nsity

0.000

0.002

0.004

0.006

0.008

Symbols – experiment, line - spline

Height above burner, mm

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Rel

ativ

e si

gnal

inte

nsity

0.000

0.005

0.010

0.015

0.020

0.025

Spatial variations of mass peak intensity m/z=65 (HTiO)in H2/O2/N2 flame.

Results and Discussion

Symbols – experiment, line - spline

m/z = 81

00,0020,0040,0060,0080,01

0,0120,0140,0160,0180,02

0 1 2 3 4 5 6

Height above burner, mm

Rel

ativ

e si

gnal

inte

nsity

Spatial variations of mass peak intensity m/z=81 (HTiO2)in H2/O2/N2 flame.

Results and Discussion

Symbols – experiment, line - spline

Spatial variations of mass peak intensity m/z=96 (TiO3)

in H2/O2/N2 flame.

Results and Discussion

0

0,0005

0,001

0,0015

0,002

0,0025

0,003

0 1 2 3 4 5 6

Height above burner, mm

Rel

ativ

e si

gnal

inte

nsity

Symbols – experiment, line - spline

0

0,0005

0,001

0,0015

0,002

0,0025

0 1 2 3 4 5

Height above burner, mm

Re

lativ

e s

ign

al i

nte

nsi

ty

Spatial variations of mass peak intensity m/z=144 (Ti2O3)in H2/O2/N2 flame.

Results and Discussion

Symbols – experiment, line - spline

Conclusion1. We were the first to measure mass-peak intensity profiles of Ti(OC3H7)4 and products of its combustion: Ti, TiH, TiO, TiO2, HTiO, HTiO2, TiO3, Ti2O3 in premixed H2/O2/N2 flame using the MBMS method.

2. A one-step reaction kinetic model for Ti(OC3H7)4 destruction used in the study, satisfactorily predicts the mass-peak intensity profile of TiO2 which is the main combustion product of Ti(OC3H7)4 in the studied flame, but poorly predicts the concentration profile of Ti(OC3H7)4.

This research was supported by Russian Foundation for Basic Research under project

#10-03-00442

Thank you!

TiO2

Ti(OC3H7)4

TiH

Ti

HTiO2

HTiOTiO

TiO3Ti2O3

Spatial variations of mass peak intensity of Ti-containing species in H2/O2/N2 flame. Results and Discussion

lines – spline for experiment