Transcript OP-01

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, Russia
2Novosibirsk state university, Novosibirsk, Russia
7th INTERNATIONAL SEMINAR ON FLAME STRUCTURE
and
FIRST YOUNG RESEARCHERS’ SCHOOL ON FLAME STUDY
Novosibirsk, Russia, July 11-19, 2011
Introduction
Application of nanocrystaline
mesoporous TiO2 films :
• Dye sensitized solar cells, DSSC
• Sensors for gas analyzers
Traditional approaches for
TiO
films
fabrication:
2
sol-gel method
•
• screen printing
• spray deposition
• doctor blading
CH3
New approach for TiO2 films fabrication by one
step in premixed lean flame C2H4/O2/Ar +
0.030.10% 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
CH3
CH
O
CH3
CH3
CH
CH3
O
Ti
O
CH3
O
CH
CH3
CH
CH3
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=3.96105exp(-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,
f = 0.45
• Numerical modeling of flame structure
using one-step reaction for Ti(OC3H7)4
thermal decomposition.
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:
MS-7302
Ion pump,
400 L/s
Liquid-nitrogen
trap
-8
5x10
torr
6,7 м м
Turbomolecular
pump, 500 L/s
Disk
chopper
Turbomolecular
pump, 500 L/s
3x10 -5
torr
Skimmer
Diffusion pump,
1100 L/s
-3
10
torr
“Sonic”
probe
Flame
Burner with burner
positioning
mechanism
EXPERIMENTAL APPROACH
Alumina ceramic probe (sonic probe) on an enlarged
scale
C o o lin g w a ter
S teel
fla n g e
A lu m in a
cera m ic
p ro b e
15 m m
The probe was clogged by
TiO2 particles for 30-50 s
of experiment and

demanded cleaning.

0.14 m m
EXPERIMENTAL APPROACH
Probe
Perforated
disk
Flame
Steel
balls
Thermostat
Ar
900С
Ti(OC3H7)4
Combustible
mixture
Combustible mixture
Thermostat
900С
(f = 0,45 )
H2/O2/Ar (13/14.5/72.5 %)+
0,12% Ti(OC3H7)4
Identified flame species
Species
m/z
H2
O2
H2O
Ti(OC3H7)4
TiO2
TiO
HTiO
HTiO2
Ti2O3
Ti
TiH
2
32
18
269
80
64
65
81
144
48
49
MODELING
• Hydrogen combustion mechanism
Konnov 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=3.96105exp(-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)
Results and Discussion
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.
Mole fraction
1.00
0.90
0.80
0.70
0.60
0.20
Ar
H2O
0.15
O2
0.10
H2
0.05
0.00
0
1
2
3
Height above burner, mm
4
5
Results and Discussion
Spatial variations of mass peak intensity m/z 269 and Ti(OC3H7)4
mole fraction in H2/O2/N2 flame.
0.0016
0.0014
m/z=269
1.0
0.0012
0.8
0.0010
0.0008
0.6
0.0006
0.4
0.0004
0.2
0.0002
0.0
0.0000
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Height above burner, mm
Symbols – experiment, line - modeling
4.0
TTIP mole fraction
Relative signal intensity
1.2
Results and Discussion
Spatial variations of mass peak intensity m/z=80 (TiO2) and
TiO2 mole fraction in H2/O2/N2 flame.
0.0016
0.05
0.0014
0.0012
0.04
0.001
0.03
0.0008
0.02
0.0006
0.0004
0.01
0.0002
0
0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
Height above burner, mm
Symbols – experiment, line - modeling
TiO2 mole fraction
Relative signal intensity
0.06
Results and Discussion
Spatial variations of mass peak intensity m/z=48 (Ti)
in H2/O2/N2 flame.
Relative signal intensity
0,045
0,04
0,035
0,03
0,025
0,02
0,015
0,01
0,005
0
0
1
2
3
4
5
Height above burner, mm
Symbols – experiment, line - spline
6
Results and Discussion
Relative signal intensity
Spatial variations of mass peak intensity m/z=49 (TiH)
in H2/O2/N2 flame.
0,06
0,05
0,04
0,03
0,02
0,01
0
0
1
2
3
4
5
Height above burner, mm
Symbols – experiment, line - spline
6
Results and Discussion
Relative signal intensity
Spatial variations of mass peak intensity m/z=64 (TiO)
in H2/O2/N2 flame.
0.008
0.006
0.004
0.002
0.000
0
1
2
3
Height above burner, mm
Symbols – experiment, line - spline
4
Results and Discussion
Relative signal intensity
Spatial variations of mass peak intensity m/z=65 (HTiO)
in H2/O2/N2 flame.
0.025
0.020
0.015
0.010
0.005
0.000
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Height above burner, mm
Symbols – experiment, line - spline
4.0
Results and Discussion
Relative signal intensity
Spatial variations of mass peak intensity m/z=81 (HTiO2)
in H2/O2/N2 flame.
0,02
0,018
0,016
0,014
0,012
0,01
0,008
0,006
0,004
0,002
0
m/z = 81
0
1
2
3
4
5
Height above burner, mm
Symbols – experiment, line - spline
6
Results and Discussion
Relative signal intensity
Spatial variations of mass peak intensity m/z=96 (TiO3)
in H2/O2/N2 flame.
0,003
0,0025
0,002
0,0015
0,001
0,0005
0
0
1
2
3
4
Height above burner, mm
Symbols – experiment, line - spline
5
6
Results and Discussion
Spatial variations of mass peak intensity m/z=144 (Ti2O3)
in H2/O2/N2 flame.
Relative signal intensity
0,0025
0,002
0,0015
0,001
0,0005
0
0
1
2
3
4
Height above burner, mm
Symbols – experiment, line - spline
5
Conclusion
1. 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!
Results and Discussion
Spatial variations of mass peak intensity of Ti-containing species in H2/O2/N2 flame.
Relative signal intensity
0.05
lines – spline for experiment
0.0014
Ti(OC3H7)4
0.04
0.0016
TiO2
0.0012
TiH
0.001
HTiO
0.03
0.0008
TiO
Ti
Ti2O3
0.02
TiO3
0.0006
0.0004
0.01
HTiO2
0
0.0002
0
0.0
1.0
2.0
3.0
4.0
Height above burner, mm
5.0
6.0
TiO2 mole fraction
0.06