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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
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