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| Titel |
Trace gas emissions from combustion of peat, crop residue, domestic biofuels, grasses, and other fuels: configuration and Fourier transform infrared (FTIR) component of the fourth Fire Lab at Missoula Experiment (FLAME-4) |
| VerfasserIn |
C. E. Stockwell, R. J. Yokelson, S. M. Kreidenweis, A. L. Robinson, P. J. DeMott, R. C. Sullivan, J. Reardon, K. C. Ryan, D. W. T. Griffith, L. Stevens |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 18 ; Nr. 14, no. 18 (2014-09-16), S.9727-9754 |
| Datensatznummer |
250119038
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| Publikation (Nr.) |
 copernicus.org/acp-14-9727-2014.pdf |
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| Zusammenfassung |
During the fourth Fire Lab at Missoula Experiment (FLAME-4, October–November
2012) a large variety of regionally and globally significant biomass fuels
was burned at the US Forest Service Fire Sciences Laboratory in Missoula,
Montana. The particle emissions were characterized by an extensive suite of
instrumentation that measured aerosol chemistry, size distribution, optical
properties, and cloud-nucleating properties. The trace gas measurements
included high-resolution mass spectrometry, one- and two-dimensional gas
chromatography, and open-path Fourier transform infrared (OP-FTIR)
spectroscopy. This paper summarizes the overall experimental design for
FLAME-4 – including the fuel properties, the nature of the burn simulations,
and the instrumentation employed – and then focuses on the OP-FTIR results. The
OP-FTIR was used to measure the initial emissions of 20 trace gases:
CO2, CO, CH4, C2H2, C2H4, C3H6,
HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO,
NO2, HONO, NH3, HCN, HCl, and SO2. These species include most
of the major trace gases emitted by biomass burning, and for several of these
compounds, this is the first time their emissions are reported for important
fuel types. The main fire types included African grasses, Asian rice straw,
cooking fires (open (three-stone), rocket, and gasifier stoves), Indonesian and
extratropical peat, temperate and boreal coniferous canopy fuels, US crop
residue, shredded tires, and trash. Comparisons of the OP-FTIR emission
factors (EFs) and emission ratios (ERs) to field measurements of biomass
burning verify that the large body of FLAME-4 results can be used to enhance
the understanding of global biomass burning and its representation in
atmospheric chemistry models.
Crop residue fires are widespread globally and account for the most burned
area in the US, but their emissions were previously poorly characterized.
Extensive results are presented for burning rice and wheat straw: two major
global crop residues. Burning alfalfa produced the highest average NH3
EF observed in the study (6.63 ± 2.47 g kg−1), while sugar cane
fires produced the highest EF for glycolaldehyde (6.92 g kg−1) and
other reactive oxygenated organic gases such as HCHO, HCOOH, and
CH3COOH. Due to the high sulfur and nitrogen content of tires, they
produced the highest average SO2 emissions (26.2 ± 2.2 g kg−1)
and high NOx and HONO emissions. High variability was
observed for peat fire emissions, but they were consistently characterized
by large EFs for NH3 (1.82 ± 0.60 g kg−1) and CH4
(10.8 ± 5.6 g kg−1). The variability observed in peat fire emissions,
the fact that only one peat fire had previously been subject to detailed
emissions characterization, and the abundant emissions from tropical
peatlands all impart high value to our detailed measurements of the
emissions from burning three Indonesian peat samples. This study also
provides the first EFs for HONO and NO2 for Indonesian peat fires. Open
cooking fire emissions of HONO and HCN are reported for the first time, and
the first emissions data for HCN, NO, NO2, HONO, glycolaldehyde, furan,
and SO2 are reported for "rocket" stoves: a common type of improved
cookstove. The HCN / CO emission ratios for cooking fires (1.72 × 10−3 ± 4.08 × 10−4)
and peat fires (1.45 × 10−2 ± 5.47 × 10−3)
are well below and above the
typical values for other types of biomass burning, respectively. This would
affect the use of HCN / CO observations for source apportionment in some
regions. Biomass burning EFs for HCl are rare and are reported for the first
time for burning African savanna grasses. High emissions of HCl were also
produced by burning many crop residues and two grasses from coastal
ecosystems. HCl could be the main chlorine-containing gas in very fresh
smoke, but rapid partitioning to aerosol followed by slower outgassing
probably occurs. |
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