Evaluation of an enclosure method for measuring emissions of volatile organic compounds from quiescent liquid surfaces

Gholson, Alex R.; Albritton, John; Jayanty, R. K. M.; Knoll, J.; Midgett, M.R.

doi:10.1021/es00015a021

Cited by 40 publications

(26 citation statements)

References 5 publications

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“…It was additionally noted that the sensitivity of this method depends on the detection limit of the analytical technique used. 9 The precision and accuracy of the flux chamber method was additionally researched by Gholson et al 10 From their laboratory studies, they found this method to have compound-dependent negative bias ranging from 40% to 80%. The source of this bias was investigated, but no definitive cause was determined.…”

Section: Introductionmentioning

confidence: 99%

The Recovery of Ammonia and Hydrogen Sulflde from Ground-Level Area Sources Using Dynamic Isolation Flux Chambers: Bench-Scale Studies

Capareda

Boriack

Mukhtar

et al. 2005

Journal of the Air & Waste Management Association

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Controlled bench-scale laboratory experiments were conducted to evaluate the recovery of ammonia (NH 3 ) and hydrogen sulfide (H 2 S) from dynamic isolation flux chambers. H 2 S (80 -4000 ppb) and NH 3 (5000 -40,000 ppb) samples were diffused through the flux chamber to simulate ground level area source emissions while measuring the inlet and outlet flux chamber concentrations simultaneously. Results showed that the recovery of H 2 S during a 30-min sampling time was almost complete for concentrations Ͼ2000 ppb. At the lowest concentration of 80 ppb, 92.55% of the H 2 S could be recovered during the given sampling period. NH 3 emissions exhibited similar behavior between concentrations of 5000 -40,000 ppb.Within the 30-min sampling period, 92.62% of the 5000-ppb NH 3 sample could be recovered. Complete recovery was achieved for concentrations Ͼ40,000 ppb. Predictive equations were developed for gas adsorption. From these equations, the maximum difference between chamber inlet and outlet concentrations of NH 3 or H 2 S was predicted to be 7.5% at the lowest concentration used for either gas.In the calculation of emission factors for NH 3 and H 2 S, no adsorption correction factor is recommended for concentrations Ͼ37,500 ppb and 2100 ppb for NH 3 and H 2 S, respectively. The reported differences in outlet and inlet concentration above these ranges are outside the fullscale sensitivity of the gas sensing equipment. The use of 46 -90 m of Teflon tubing with the flux chambers has apparently no effect on gas adsorption, because recovery was completed almost instantaneously at the beginning of the tests.

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Section: Introductionmentioning

confidence: 99%

The Recovery of Ammonia and Hydrogen Sulflde from Ground-Level Area Sources Using Dynamic Isolation Flux Chambers: Bench-Scale Studies

Capareda

Boriack

Mukhtar

et al. 2005

Journal of the Air & Waste Management Association

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“…The chamber covers 20.8 % of the liquid surface and occupies 5 % of the channel section in the wind tunnel. For similar ratio, some authors [6] have already found an influence due to the flux chamber present. In real environment, the flux chamber would be expected to exert a much smaller impact on the total emission.…”

Section: Aerodynamic Studymentioning

confidence: 64%

“…Emitted odour and odorous compounds concentration are measured in the exit gas. These direct sampling systems are divided into two groups: static [5][6][7][8][9] and dynamic systems [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Laboratory study of odour emissions from areal sources: evaluation of a sampling system

Leyris¹,

Maupetit²,

Guillot³

et al. 2000

Analusis

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“…Results from this study were deemed inconclusive, and a more detailed study was recommended. There was no effort put into explaining result discrepancies for this specific study, but it is interesting to note that Gholson et al 5 reported that the flux chamber method was not found to be accurate. Measurement results consistently showed a negative bias of ϳ50%.…”

Section: Introductionmentioning

confidence: 72%

Estimation of Vinyl Chloride Emissions from Gasholders and Validation of In Situ Emission Reduction Methods

Verville

Guy

Caron

2004

Journal of the Air & Waste Management Association

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Gasholders consist of a floating bell in a tank filled with water. Water provides a seal between the enclosed gas and ambient air. Gasholder emissions come from the contaminated water seal exposed to ambient air and the wet bell wall. The study objectives were to define parameters influencing gasholder emissions, determine the quantities of vinyl chloride (VC) emitted, generate a correlation equation between parameters of influence and mass emissions, and evaluate the efficiency of emission reduction methods. The research project was carried out on a laboratory-scale representation of a gasholder. The classic twophase resistance model was used successfully to generate a correlation equation, which can be used to calculate the gasholder water seal emissions. A strictly empirical model was generated to estimate the wet wall emissions. Two in situ reduction methods were evaluated with the laboratory installations: floating objects and an oil layer. Both methods showed significant emission reductions, but the oil layer was the most effective. To reduce emissions even further, it is recommended that the water level of the gasholder be set to the lowest achievable level, that a windshield be placed around the water seal perimeter, and that hydrophobic paint be used on the bell wall. INTRODUCTIONMany polyvinyl chloride (PVC) manufacturing plants located in Europe use gasholders to store vinyl chloride (VC) left over from the PVC manufacturing process. Gasholders consist of a cylindrical bell floating in a tank filled with water. The water provides a seal between VC trapped in the bell and ambient air. As gas is fed to or pulled from the gasholder, pressure in the bell changes, creating an upward or downward movement. Because water in the gasholder bell section is constantly in contact with VC gases, its VC concentration increases until it reaches almost full saturation. The water section of the gasholder that is exposed to air (water seal section) steadily emits its VC content directly in the environment. Also, the bell's upward movement, as gas is fed to the gasholder, exposes a wet surface on the bell wall. As the water evaporates from the wall, additional VC emissions are generated. Figure 1 illustrates the two sources of emissions from gasholders.On a few of the PVC plants' gasholders, a mineral oil film of ϳ1 cm is used to cover the water seal. This oil film is meant as a corrosion reduction method because it covers the bell walls as it rises, replacing the usual water layer that causes corrosion. Even if emission reduction is not the purpose of the presence of oil on the water seal, the oil layer is considered to be an efficient method to reduce air emissions. 1 To reduce the water seal emissions, the PVC manufacturers also use floating hollow spheres. Theoretically, this method should achieve a high water seal emission reduction percentage, but this has yet to be proven in the environment, especially in a wind-affected irregular surface like a gasholder water seal.Because VC is a known carcinogen 2 and b...

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Evaluation of an enclosure method for measuring emissions of volatile organic compounds from quiescent liquid surfaces

Cited by 40 publications

References 5 publications

The Recovery of Ammonia and Hydrogen Sulflde from Ground-Level Area Sources Using Dynamic Isolation Flux Chambers: Bench-Scale Studies

The Recovery of Ammonia and Hydrogen Sulflde from Ground-Level Area Sources Using Dynamic Isolation Flux Chambers: Bench-Scale Studies

Laboratory study of odour emissions from areal sources: evaluation of a sampling system

Estimation of Vinyl Chloride Emissions from Gasholders and Validation of In Situ Emission Reduction Methods

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