In Situ Method To Measure Effective and Sorption-Affected Gas-Phase Diffusion Coefficients in Soils

2003 ◽  
Vol 37 (11) ◽  
pp. 2502-2510 ◽  
Author(s):  
David Werner ◽  
Patrick Höhener
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Phase Diffusion ◽  
In Situ Method

Measurement of in Situ Gas-Phase Diffusion Coefficients

2000 ◽  
Vol 21 (6) ◽  
pp. 631-640 ◽  
Author(s):  
I. Hers ◽  
R. Zapf-Gilje ◽  
L. Li ◽  
J. Atwater
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Phase Diffusion

NEW METHOD FOR PREDICTION OF BINARY GAS-PHASE DIFFUSION COEFFICIENTS

1966 ◽  
Vol 58 (5) ◽  
pp. 18-27 ◽  
Author(s):  
Edward N. Fuller ◽  
Paul D. Schettler ◽  
J. Calvin. Giddings
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
New Method ◽  
Phase Diffusion

scholarly journals Technical note: Determination of binary gas-phase diffusion coefficients of unstable and adsorbing atmospheric trace gases at low temperature – arrested flow and twin tube method

2020 ◽  
Vol 20 (6) ◽  
pp. 3669-3682 ◽  
Author(s):  
Stefan Langenberg ◽  
Torsten Carstens ◽  
Dirk Hupperich ◽  
Silke Schweighoefer ◽  
Ulrich Schurath
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Trace Gases ◽  
Heterogeneous Reactions ◽  
Viscosity Data ◽  
Atmospheric Conditions ◽  
Binary Diffusion ◽  
Phase Diffusion ◽  
Flow Method ◽  
Binary Diffusion Coefficients

Abstract. Gas-phase diffusion is the first step for all heterogeneous reactions under atmospheric conditions. Knowledge of binary diffusion coefficients is important for the interpretation of laboratory studies regarding heterogeneous trace gas uptake and reactions. Only for stable, nonreactive and nonpolar gases do well-established models for the estimation of diffusion coefficients from viscosity data exist. Therefore, we have used two complementary methods for the measurement of binary diffusion coefficients in the temperature range of 200 to 300 K: the arrested flow method is best suited for unstable gases, and the twin tube method is best suited for stable but adsorbing trace gases. Both methods were validated by the measurement of the diffusion coefficients of methane and ethane in helium and air as well as nitric oxide in helium. Using the arrested flow method the diffusion coefficients of ozone in air, dinitrogen pentoxide and chlorine nitrate in helium, and nitrogen were measured. The twin tube method was used for the measurement of the diffusion coefficient of nitrogen dioxide and dinitrogen tetroxide in helium and nitrogen.

scholarly journals Compilation and evaluation of gas-phase diffusion coefficients of reactive trace gases in the atmosphere: volume 2. Organic compounds and Knudsen numbers for gas uptake calculations

2015 ◽  
Vol 15 (4) ◽  
pp. 5461-5492 ◽  
Author(s):  
M. J. Tang ◽  
M. Shiraiwa ◽  
U. Pöschl ◽  
R. A. Cox ◽  
M. Kalberer
Keyword(s):  
Gas Phase ◽  
Organic Compounds ◽  
Diffusion Coefficients ◽  
Inorganic Compounds ◽  
Measurement Data ◽  
Gas Uptake ◽  
Phase Diffusion ◽  
Knudsen Numbers ◽  
Wide Range ◽  
Cloud Particles

Abstract. Diffusion of organic vapours to the surface of aerosol or cloud particles is an important step for the formation and transformation of atmospheric particles. So far, however, a database of gas phase diffusion coefficients for organic compounds of atmospheric interest has not been available. In this work we have compiled and evaluated gas phase diffusivities (pressure-independent diffusion coefficients) of organic compounds reported by previous experimental studies, and we compare the measurement data to estimates obtained with Fuller's semi-empirical method. The difference between measured and estimated diffusivities are mostly < 10%. With regard to gas-particle interactions, different gas molecules, including both organic and inorganic compounds, exhibit similar Knudsen numbers (Kn) although their gas phase diffusivities may vary over a wide range. Knudsen numbers of gases with unknown diffusivity can be approximated by a simple function of particle diameter and pressure and can be used to characterize the influence of diffusion on gas uptake by aerosol or cloud particles. We use a kinetic multi-layer model of gas-particle interaction to illustrate the effects of gas phase diffusion on the condensation of organic compounds with different volatilities. The results show that gas-phase diffusion can play a major role in determining the growth of secondary organic aerosol particles by condensation of low-volatility organic vapours.

Determination of binary gas-phase diffusion coefficients using chromatography

1986 ◽  
Vol 31 (1) ◽  
pp. 100-102 ◽  
Author(s):  
S. M. Ashraf ◽  
R. Srivastava ◽  
Asghar Hussain
Keyword(s):  
Gas Phase ◽  
Diffusion Coefficients ◽  
Phase Diffusion

scholarly journals Compilation and evaluation of gas phase diffusion coefficients of reactive trace gases in the atmosphere: Volume 2. Diffusivities of organic compounds, pressure-normalised mean free paths, and average Knudsen numbers for gas uptake calculations

2015 ◽  
Vol 15 (10) ◽  
pp. 5585-5598 ◽  
Author(s):  
M. J. Tang ◽  
M. Shiraiwa ◽  
U. Pöschl ◽  
R. A. Cox ◽  
M. Kalberer
Keyword(s):  
Gas Phase ◽  
Organic Compounds ◽  
Diffusion Coefficients ◽  
Inorganic Compounds ◽  
Measurement Data ◽  
Phase Diffusion ◽  
Knudsen Numbers ◽  
Wide Range ◽  
Gas Molecules ◽  
Cloud Particles

Abstract. Diffusion of organic vapours to the surface of aerosol or cloud particles is an important step for the formation and transformation of atmospheric particles. So far, however, a database of gas phase diffusion coefficients for organic compounds of atmospheric interest has not been available. In this work we have compiled and evaluated gas phase diffusivities (pressure-independent diffusion coefficients) of organic compounds reported by previous experimental studies, and we compare the measurement data to estimates obtained with Fuller's semi-empirical method. The difference between measured and estimated diffusivities are mostly < 10%. With regard to gas-particle interactions, different gas molecules, including both organic and inorganic compounds, exhibit similar Knudsen numbers (Kn) although their gas phase diffusivities may vary over a wide range. This is because different trace gas molecules have similar mean free paths in air at a given pressure. Thus, we introduce the pressure-normalised mean free path, λP ≈ 100 nm atm, as a near-constant generic parameter that can be used for approximate calculation of Knudsen numbers as a simple function of gas pressure and particle diameter to characterise the influence of gas phase diffusion on the uptake of gases by aerosol or cloud particles. We use a kinetic multilayer model of gas-particle interaction to illustrate the effects of gas phase diffusion on the condensation of organic compounds with different volatilities. The results show that gas phase diffusion can play a major role in determining the growth of secondary organic aerosol particles by condensation of low-volatility organic vapours.

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