DOAS for flue gas monitoring—III. In-situ monitoring of sulfur dioxide, nitrogen monoxide and ammonia

Mellqvist, Johan; Axelsson, Håkan; Rosén, Arne

doi:10.1016/0022-4073(96)00044-1

Cited by 39 publications

(15 citation statements)

References 6 publications

(1 reference statement)

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“…Qualitative information on the UV absorption characteristics of gaseous KCl and NaCl at elevated temperatures was given by Daminelli et al 16 and Davidovits and Brodhead. 17 The absorption of SO 2 in flue gas in the UV range was described by Mellqvist et al, 18 but the temperatures of the gas were much lower than those of the IACM application.…”

Section: Calibrationmentioning

confidence: 96%

Principle, calibration, and application of the in situ alkali chloride monitor

Forsberg

Broström

Backman

et al. 2009

Review of Scientific Instruments

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The extended use of biomass for heat and power production has caused increased operational problems with fouling and high-temperature corrosion in boilers. These problems are mainly related to the presence of alkali chlorides (KCl and NaCl) at high concentrations in the flue gas. The in situ alkali chloride monitor (IACM) was developed by Vattenfall Research and Development AB for measuring the alkali chloride concentration in hot flue gases (less than or approximately 650 degrees C). The measurement technique is based on molecular differential absorption spectroscopy in the UV range. Simultaneous measurement of SO(2) concentration is also possible. The measuring range is 1-50 ppm for the sum of KCl and NaCl concentrations and 4-750 ppm for SO(2). This paper describes the principle of the IACM as well as its calibration. Furthermore, an example of its application in an industrial boiler is given.

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Section: Calibrationmentioning

confidence: 96%

Principle, calibration, and application of the in situ alkali chloride monitor

Forsberg

Broström

Backman

et al. 2009

Review of Scientific Instruments

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“…When recording spectra with a resolution higher than the line width, precise quantitative analysis requires the use of multiple reference spectra. Another solution is to use a calibration curve to correct the retrieved concentrations [35,36]. This calibration curve has to be evaluated regularly because of the changes with time of the instrumental function of the spectrograph.…”

Section: H=o Vapourmentioning

confidence: 99%

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

Hermans

Vandaele

Carleer

et al. 1999

Environ. Sci. & Pollut. Res.

130

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Absorption spectroscopy, which is widely used for concentration measurements of tropospheric and stratospheric compounds, requires precise values of the absorption cross-sections of the measured species. NO v 02 and its collision-induced absorption spectrum, and H20 absorption cross-sections have been measured at temperature and pressure conditions prevailing in the Earth's atmosphere. Corrections to the generally accepted analysis procedures used to resolve the convolution problem are also proposed.

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“…This is discussed in an additional paper. 24 Although the linearity was independent of temperature for NO this is not necessarily true for other species. Another interesting question is whether the nonlinearity is affected by spectral interference.…”

Section: Discussionmentioning

confidence: 97%

DOAS for flue gas monitoring—II. Deviations from the Beer-Lambert law for the U.V./visible absorption spectra of NO, NO2, SO2 and NH3

Mellqvist

Rosén

1996

Journal of Quantitative Spectroscopy and Radiative Transfer

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Abstract-Deviationsfrom the Beer-Lambert law were studied for the differential absorption cross-sections for NO, SOz, NO, and NH,. This was performed by simple calculations, computer simulations of spectra and by recordings of spectra for the above mentioned species at various total columns. The linearity studies for the DOAS instrument displayed large variations for the molecules studied and for different wavelength bands. In a calculation it was shown that the optical depth deviated from a linear concentration dependence by a term which was directly proportional to the statistical variance of the true absorption cross sections and proportional to the square of the total column, under the assumption of a boxcar instrument lineshape. Species exhibiting little variance or fine structure in their spectra, for instance NO*, displayed a larger linear region compared with molecules exhibiting a rich structure, i.e., NO. The former species was linear to a total column of 3150 mg/m*, which correspond to a maximum optical depth of 0.7, while the latter was linear to only 6 mg/m2, corresponding to a maximum optical depth of 0.024, in the resolution range studied. The linear regions for the other species studied were 90 mg/m* for SO2 at 230 nm, 180 mg/m* for SO2 at 300 nm and 36 mg/m* for NH,. The main effect of the nonlinearity was to cause a reduction in the peak height of the absorption. It was shown that the nonlinearity effect is independent on the spectral resolution when a large number of absorption lines are covered by the bandpass of the instrument. It was also shown that the largest change in linearity occurs when the resolution is similar in magnitude to the absorption linewidth. The nonlinear behavior for NO varied less than 2% in the temperature range 300-1000 K and the spectral resolution range 0.25-l nm. The nonlinearity effect caused quantitative rather than qualitative changes of the spectral features and typical relative errors can be as high as 35% in a flue gas. Copyright 0 1996

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DOAS for flue gas monitoring—III. In-situ monitoring of sulfur dioxide, nitrogen monoxide and ammonia

Cited by 39 publications

References 6 publications

Principle, calibration, and application of the in situ alkali chloride monitor

Principle, calibration, and application of the in situ alkali chloride monitor

Absorption cross-sections of atmospheric constituents: NO2, O2, and H2O

DOAS for flue gas monitoring—II. Deviations from the Beer-Lambert law for the U.V./visible absorption spectra of NO, NO2, SO2 and NH3

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