why the ftir? · 2021. 1. 4. · why the ftir? ifrf goal is to use ftir for in-flame measurement...
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Why the FTIR?Why the FTIR?
IFRF goal is to use FTIR for in-flame measurement t ti f it i (NO NO HCN NH N O)concentration of nitrogen species (NO, NO2, HCN, NH3, N2O)
Punctual concentrations of NOX species and precursors are X p pextremely valuable for the study of the NOX formation kinetics
In addition the FTIR approach offers other important informationIn addition the FTIR approach offers other important information such as H2O and SO2 concentrations (and others species)
What is the FTIR?What is the FTIR?The FTIR is a real time gas analyser
Species Range Minimum
Initial measured species Additional species added for spectra analysis
H2O 0-25% vol. 0-1% vol.CO2 0-70% vol. 0-200 ppmCO 0-20% vol. 0-20 ppmN2O 0-100 ppm 0-50 ppm
Species RangeCH4 0-20000 ppmC2H6 0-100 ppmC3H8 0-100 ppmC4H10 0-100 ppmC H 0 100
30%100%Ppm measurement
N2O 0 100 ppm 0 50 ppmNO 0-1500 ppm 0-100 ppmNO2 300 ppm 0-100 ppmSO2 2000 ppm 0-30 ppmNH3 200 ppm 0-20 ppm
C2H4 0-100 ppmC2H2 0-100 ppmCHOH 0-100 ppmHCl 0-100 ppmHF 0-100 ppmC3H6 0-100 ppm3 00 pp 0 0 pp
HCN 300 ppm 0-50 ppm C4H6 0-100 ppm
Working principles of FTIRWorking principles of FTIR
Step 1Mi h l i t f t
Moving mirror
ensi
ty
Infrared
Michelson interferometerMirror position 1
Source
Beamsplitter
Radiation to the sample gas and detector
Fixed mirror
Ligh
t int
e
Broadband source
wavelength
Cell full of li
Light detector
FTIR analysisSpectrum point
sampling gasrecord the intensity
Working principles of FTIRWorking principles of FTIR
Step 2Mi h l i t f t
Light signal centred at a different wavelength
Moving mirror
ensi
ty
Infrared
Michelson interferometerMirror position 2
Source
Beamsplitter
Radiation to the sample gas and detector
Fixed mirror
Ligh
t int
e
Broadband source
wavelength
Cell full of li
Light detector
FTIR analysisSpectrum point 1
Spectrum point 2
sampling gasrecord the intensity
Working principles of FTIRWorking principles of FTIR
Residual spectrum Typical spectrum of FTIR (and CO2 spectrum)
CO2
IFRF FTIR systemIFRF FTIR system
11stst FTIR inFTIR in--measurements testsmeasurements tests
The first tests with the FTIR measurement system were carried out on the 14th May 2010 in Fosper during NG testsout on the 14 May 2010 in Fosper during NG tests
14 July 2010Port 2 CO2 vs radial distance
2
4
6
8
10C
O2
%Port 2 CO2 vs radial distance
CO2 FTIR
CO2 ENELSomething is not
-1000 -800 -600 -400 -200 0
-4
-2
0
2
Radial distance from burner axismm
is not right….
11stst FTIR inFTIR in--measurements testsmeasurements tests
The first tests with the FTIR measurement system were carried out on the 14th May 2010 in Fosper during NG testsout on the 14 May 2010 in Fosper during NG tests
The FTIRdidn’tresolve theresolve the spectrum!!!
IssuesIssues
• High concentration of water vapourg p• High concentration of unburnt
hydrocarbons (different kind of FTIR??)hydrocarbons (different kind of FTIR??)
H O and h drocarbons absorbs inH2O and hydrocarbons absorbs in the infrared rangethe infrared range
Th fi l i l t tThe final signal saturates (more precisely the signal at the FTIR detector is too low)
List of tests with FTIRList of tests with FTIR
• July 2010 – Fosper NG – FTIR testsN /D 2010 F C l O• Nov/Dec 2010 – Fosper Coal - Oxycorr
• Aug/Sept 2011 – Lab tests – FTIR tests• Sept 2011- Fosper NG – ENEA probes testSept 2011 Fosper NG ENEA probes test• Sept 2012 – Casper NG – FTIR tests• March/ April 2013 – IPFR – Nitrogen species tests
N 2013 F C l R l• Nov 2013 – Fosper Coal – Relcom• June 2014 – CIUDEN PC boiler Coal – Relcom
More than 200 measurement points (at least 9 chemical species per point)
More than 3000 spectra
Ideas for developmentIdeas for development
• Dilution of sampled gases p gwith N2
E h t l l i• Enhance spectral analysis
Dilution system schemeDilution system scheme
Results of dilutionResults of dilution
NO measured /calculated vs dilution ratio
No measurement of N2 flow Constant CO2 method
21 September 2011
Measurement of N2 flow
300
350
400
450
NO measured /calculated vs dilution ratiodiffusion flame
50.00
60.00
70.00
pCO2 vs dilution ratio port 14
0
50
100
150
200
250
NO
ppm NO meas diff
NO calc diff
0 00
10.00
20.00
30.00
40.00
CO2
%
CO2 FTIR
CO2 ENEL
0 5 10 15 20 25 30 350
1/ϕ 0 5 10 15 20 25 300.00
1/ϕ15 September 2011
Methods comparison
300.0
400.0
500.0
O m
pNO measured /calculated vs dilution ratio
NO meas
-100.0
0.0
100.0
200.0NO
ppm NO meas
NO calc by CO2
NO calc by N2
0 5 10 15 20 25 30 351/ϕ
Spectral analysisSpectral analysis
The spectral analysis may be improved by:
Addi i t f i i• Adding more interfering species• Adjusting the frequency range of comparison for the
different species p
Spectral analysisSpectral analysisDefault analysis
Improved analysisImproved analysis
Thi h d d lid i d i i i iThis method needs validation and it is time consuming
Latest Latest measurements measurements resultsresultsAir coal combustion CIUDEN
CO2 NO SO2
1314151617181920
CO
2%
6507007508008509009501000
NO
ppm
300400500600700800
SO2
ppm
CO2 NO 2
???-2500 -2000 -1500 -1000 -500 0
10111213
Furnace axis distancemm
CO2 FTIR port 3
-2500 -2000 -1500 -1000 -500 0500550600650
Furnace axis distancemm
NO FTIR port 3
-2500 -2000 -1500 -1000 -500 00100200
Furnace axis distancemmSO2 FTIR port 3
OK!!! OK!!!???
Oxy-coal combustion CIUDEN
CO2 ENEL port 3 NO ENEL port 3 SO2 ENEL port 3
CO2 SO2NO
8808284868890
CO
2% 800
900
1000
1100
1200
NO
ppm 2250
2500
2750
3000
SO2
ppm
2 SO2NO
-2500 -2000 -1500 -1000 -500 07072747678
Furnace axis distancemm
-2500 -2000 -1500 -1000 -500 0400
500
600
700
Furnace axis distancemm
N p-2500 -2000 -1500 -1000 -500 0
1500
1750
2000
Furnace axis distancemm
S p
OK!!!??? ???
CO2 FTIR port 3
CO2 ENEL port 3
NO FTIR port 3
NO ENEL port 3
mmSO2 FTIR port 3
SO2 ENEL port 3
Actual IFRF analyser performance Actual IFRF analyser performance -- 11
• FTIR is a reliable instrument for emission measurements at h hi i i b i di ithe chimney in air combustion condition
• In coal flames the FTIR manage to resolve the spectra at theIn coal flames the FTIR manage to resolve the spectra at the majority of positions. Just few points (2 or 3 out of 30 in the last campaign) are still not measureable. But…
th lt f th FTIR b diff t f ti l• ….the results of the FTIR can be different from conventional analysers (Siemens, ABB)
• In gas flames the FTIR cannot perform measurements in the region very close to the burner exit
Actual IFRF analyser performance Actual IFRF analyser performance -- 22
• In laboratory with bottles of pure gases there are no diff b h f h FTIR ddifferences between the measurements of the FTIR and conventional (Siemens, ABB) analysers
• Hence the differences must be due to the presence of water vapour or of different chemical species at the same time
Valuable outcomes Valuable outcomes –– IPFR testsIPFR testsN-species in-flame measurements
IPFR b t• IPFR precombustor• NG-air combustion• Flame doped with central injection of
NH3/water solution at different
Flame borderflowrates
Burner
Flue gasFlame axis
Valuable outcomes Valuable outcomes –– IPFR testsIPFR testsOther species in-flame measurements
CH4 C2H2
1500
2000
2500
ion
[ppm
]
100
150
200
ion
[ppm
]
fl
0
500
1000
Conc
entr
at flue gas
flame axis
flame border
0
50
100
Conc
entr
at flue gas
flame axis
flame border
0 100 200 300 400 500
NH3 solution flowrate [g/h]0 100 200 300 400 500
NH3 solution flowrate [g/h]
50
H2O
20
30
40
50
trat
ion
[vol
-%]
flue gas
flame axis
0
10
0 100 200 300 400 500
Conc
ent
NH3 solution flowrate [g/h]
flame border
Further developmentsFurther developments
• Calibration with a mixture of gas (possibly g (p ywith water vapour)
• Coupling of two FTIR results (nitrogenCoupling of two FTIR results (nitrogen species and hydrocarbon)
• Enhance spectral analysis and validation• Enhance spectral analysis and validation of the method
• Other ideas???
Thank you for yourThank you for yourThank you for your Thank you for your attentionattentionattention attention
!!