Laboratory studies of submicron particles from coal combustion

1981 ◽  
Vol 18 (1) ◽  
pp. 1227-1237 ◽  
Author(s):  
Richard C. Flagan ◽  
Dean D. Taylor
Keyword(s):  
Coal Combustion ◽  
Submicron Particles ◽  
Laboratory Studies

scholarly journals Insights on organic aerosol aging and the influence of coal combustion at a regional receptor site of Central Eastern China

2013 ◽  
Vol 13 (4) ◽  
pp. 10809-10858 ◽  
Author(s):  
W. W. Hu ◽  
M. Hu ◽  
B. Yuan ◽  
J. L. Jimenez ◽  
Q. Tang ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
Coal Combustion ◽  
Eastern China ◽  
Organic Aerosols ◽  
Receptor Site ◽  
Organic Aerosol ◽  
Submicron Particles ◽  
Central Eastern ◽  
Photochemical Age

Abstract. In order to understand the aging and processing of organic aerosols (OA), an intensive field campaign (Campaign of Air Pollution at Typical Coastal Areas In Eastern China, CAPTAIN) was conducted in March–April at a receptor site (Changdao Island) in Central Eastern China. Multiple fast aerosol and gas measurement instruments were used during the campaign, including a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was applied to measure mass concentrations and non-refractory chemical components of submicron particles (PM1nr). The average mass concentration of PM1 (PM1nr + black carbon) was 47 ± 36 μg m−3 during the campaign and showed distinct variation depending on back trajectories and their overlap with source regions. Organic aerosol (OA) is the largest component of PM1 (30%), followed by nitrate (28%), sulfate (19%), ammonium (15%), black carbon (6%), and chloride (3%). Four OA components were resolved by Positive Matrix Factorization (PMF) of the high-resolution spectra, including low-volatility oxygenated organic aerosol (LV-OOA), semi-volatile oxygenated OA (SV-OOA), hydrocarbon-like OA (HOA) and a coal combustion OA (CCOA), reported here for the first time. The mass spectrum of CCOA has high abundance of fragments from polycyclic aromatic hydrocarbons (PAHs) (m/z 128, 152, 178 etc.). The average atomic ratio of oxygen to carbon in OA (O/C) at Changdao is 0.59, which is comparable to other field studies reported at locations downwind of large pollution sources, indicating the oxidized nature of most OA during the campaign. The evolution of OA elemental composition in the Van Krevelen diagram (H/C vs. O/C) shows a slope of −0.63, however, the OA influenced by coal combution exhibits a completely different evolution that appears dominated by physical mixing. The aging of organic aerosols vs. with photochemical age was investigated. It is shown that OA/ΔCO, as well as LV-OOA/ΔCO and SV-OOA/ΔCO, positively correlated with photochemical age. LV-OOA accounted for 73% of the OA secondary formation in the oldest plumes (photochemical age of 25 h). The kOH at Changdao by assuming SOA formation and aging as a first-order process proportional to OH was calculated to be is 5.2 × 10−12 cm3 molec−1 s−1 which is similar to those determined in recent studies of polluted air in other continents.

Emission and simulation of primary fine and submicron particles and water-soluble ions from domestic coal combustion in China

2020 ◽  
Vol 224 ◽  
pp. 117308 ◽  
Author(s):  
Qin Yan ◽  
Shaofei Kong ◽  
Yingying Yan ◽  
Haibiao Liu ◽  
Wei Wang ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Water Soluble ◽  
Submicron Particles ◽  
Soluble Ions ◽  
Water Soluble Ions

scholarly journals Insights on organic aerosol aging and the influence of coal combustion at a regional receptor site of central eastern China

2013 ◽  
Vol 13 (19) ◽  
pp. 10095-10112 ◽  
Author(s):  
W. W. Hu ◽  
M. Hu ◽  
B. Yuan ◽  
J. L. Jimenez ◽  
Q. Tang ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
Coal Combustion ◽  
Eastern China ◽  
Organic Aerosols ◽  
Receptor Site ◽  
Organic Aerosol ◽  
Submicron Particles ◽  
Central Eastern ◽  
Photochemical Age

Abstract. In order to understand the aging and processing of organic aerosols (OA), an intensive field campaign (Campaign of Air Pollution at Typical Coastal Areas IN Eastern China, CAPTAIN) was conducted March–April at a receptor site (a Changdao island) in central eastern China. Multiple fast aerosol and gas measurement instruments were used during the campaign, including a high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) that was applied to measure mass concentrations and non-refractory chemical components of submicron particles (PM1nr). The average mass concentration of PM1(PM1nr+black carbon) was 47 ± 36 μg m−3 during the campaign and showed distinct variation, depending on back trajectories and their overlap with source regions. Organic aerosol (OA) is the largest component of PM1 (30%), followed by nitrate (28%), sulfate (19%), ammonium (15%), black carbon (6%), and chloride (3%). Four OA components were resolved by positive matrix factorization (PMF) of the high-resolution spectra, including low-volatility oxygenated organic aerosol (LV-OOA), semi-volatile oxygenated OA (SV-OOA), hydrocarbon-like OA (HOA) and a coal combustion OA (CCOA). The mass spectrum of CCOA had high abundance of fragments from polycyclic aromatic hydrocarbons (PAHs) (m/z 128, 152, 178, etc.). The average atomic ratio of oxygen to carbon in OA (O / C) at Changdao was 0.59, which is comparable to other field studies reported at locations downwind of large pollution sources, indicating the oxidized nature of most OA during the campaign. The evolution of OA elemental composition in the van Krevelen diagram (H / C vs. O / C) showed a slope of −0.63; however, the OA influenced by coal combustion exhibits a completely different evolution that appears dominated by physical mixing. The aging of organic aerosols vs. photochemical age was investigated. It was shown that OA / ΔCO, as well as LV-OOA / ΔCO and SV-OOA / ΔCO, positively correlated with photochemical age. LV-OOA accounted for 73% of the OA secondary formation (SOA) in the oldest plumes (photochemical age of 25 h). The kOH at Changdao, by assuming SOA formation and aging as a first-order process proportional to OH, was calculated to be 5.2 × 10−12 cm3 molec.−1 s−1, which is similar to those determined in recent studies of polluted air in other continents.

Characterization of submicron particles during biomass burning and coal combustion periods in Beijing, China

2016 ◽  
Vol 562 ◽  
pp. 812-821 ◽  
Author(s):  
J.K. Zhang ◽  
M.T. Cheng ◽  
D.S. Ji ◽  
Z.R. Liu ◽  
B. Hu ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Coal Combustion ◽  
Submicron Particles ◽  
Beijing China

scholarly journals Evaluation of the new capture vaporizer for Aerosol Mass Spectrometers (AMS) through laboratory studies of inorganic species

2016 ◽  
Author(s):  
Weiwei Hu ◽  
Pedro Campuzano-Jost ◽  
Douglas A. Day ◽  
Philip Croteau ◽  
Manjula R. Canagaratna ◽  
...  
Keyword(s):  
Collection Efficiency ◽  
Submicron Particles ◽  
Size Distributions ◽  
Laboratory Studies ◽  
Volatile Species ◽  
Pure Species ◽  
Mass Spectrometers ◽  
Aerosol Mass ◽  
Aerosol Mass Concentration ◽  
Inorganic Species

Abstract. Aerosol mass spectrometers (AMS) and Aerosol Chemical Speciation Monitors (ACSM) commercialized by Aerodyne Research Inc. are used widely to measure the mass concentrations and size distributions of non-refractory species in submicron-particles. With the "standard" vaporizer (SV) that is installed in all commercial instruments to date, the quantification of ambient aerosol mass concentration requires the use of a collection efficiency (CE) for correcting the loss of particles due to bounce on the SV. However, CE depends on aerosol phase, and thus can vary with location, airmass, and season of sampling. Although a composition-dependent parameterization of CE in the SV for ambient data has been successful, CE still contributes most of the estimated uncertainty to reported concentrations, and is also an important uncertainty in laboratory studies. To address this limitation, a new "capture" vaporizer (CV) has been designed to reduce or eliminate particle bounce and thus the need for a CE correction. To test the performance of the CV, two high-resolution AMS instruments, one with a SV and one with a CV were operated side by side in the laboratory. Four standard species NH4NO3, NaNO3, (NH4)2SO4 and NH4Cl, which typically constitute the majority of the mass of ambient submicron inorganic species, are studied. The effect of vaporizer temperature (Tv ~ 200–800 ℃) on the detected fragments, CE and size distributions are investigated. A Tv of 500–550 ℃ for the CV is recommended based on the observed performance. In the CV, CE was identical (around unity) for more volatile species and comparable or higher compared to the SV for less volatile species, demonstrating a substantial improvement in CE of inorganic species in the CV. The detected fragments of NO3 and SO4 species observed with the CV are different than those observed with the SV, suggesting additional thermal decomposition arising from the increased residence time and hot surface collisions. Longer particle detection times lead to broadened particle size distribution measurements made with the AMS. The degradation of CV size distributions due to this broadening is significant for laboratory studies using monodisperse particles, but minor for field studies since ambient distributions are typically quite broad. A method for estimating whether pure species will be detected in AMS sizing mode is proposed. Production of CO2(g) from sampled nitrate on the vaporizer surface, which has been reported for the SV, is negligible for the CV for NH4NO3 and comparable to the SV for NaNO3. Adjusting the alignment of aerodynamic lens to focus particles on the edge of the CV results in higher resolution size distributions, which can be useful in some laboratory experiments. We observe an extremely consistent detection of ammonium from different inorganic ammonium salts, independent of the vaporizer types and/or the Tv. This contradicts a recent suggestion by Murphy (2016) that inorganic species evaporate as intact salts in the AMS.

scholarly journals Laboratory studies of the aqueous-phase oxidation of polyols: submicron particles vs. bulk aqueous solution

2014 ◽  
Vol 14 (9) ◽  
pp. 13649-13680 ◽  
Author(s):  
K. E. Daumit ◽  
A. J. Carrasquillo ◽  
J. F. Hunter ◽  
J. H. Kroll
Keyword(s):  
Aqueous Phase ◽  
Liquid Water ◽  
Water Soluble ◽  
Bulk Phase ◽  
Submicron Particles ◽  
Laboratory Studies ◽  
Cloud Droplets ◽  
Fenton Chemistry ◽  
Phase Oxidation ◽  
Aqueous Oxidation

Abstract. Oxidation in the atmospheric aqueous phase (cloud droplets and deliquesced particles) has received recent attention as a potential pathway for the formation of highly oxidized organic aerosol. Most laboratory studies of aqueous-phase oxidation, however, are carried out in bulk solutions rather than aqueous droplets. Here we describe experiments in which aqueous oxidation of polyols (water-soluble species with chemical formula CnH2n+2On) is carried out within submicron particles in an environmental chamber, allowing for significant gas-particle partitioning of reactants, intermediates, and products. Dark Fenton chemistry is used as a source of hydroxyl radicals, and oxidation is monitored using a high-resolution aerosol mass spectrometer (AMS). Aqueous oxidation is rapid, and results in the formation of particulate oxalate; this is accompanied by substantial loss of carbon to the gas phase, indicating the formation of volatile products. Results are compared to those from analogous oxidation reactions carried out in bulk solution. The bulk-phase chemistry is similar to that in the particles, but with substantially less carbon loss. This is likely due to differences in partitioning of early-generation products, which evaporate out of the aqueous phase under chamber conditions (in which liquid water content is low), but remain in solution for further aqueous processing in the bulk phase. This work suggests that the product distributions from oxidation in aqueous aerosol may be substantially different from those in bulk oxidation experiments. This highlights the need for aqueous oxidation studies to be carried out under atmospherically relevant partitioning conditions, with liquid water contents mimicking those of cloud droplets or aqueous aerosol.

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