An Exact Expression for the Diffusion Slip Velocity in a Binary Gas Mixture

1970 ◽  
Vol 13 (7) ◽  
pp. 1871 ◽  
Author(s):  
H. Lang
Keyword(s):  
Slip Velocity ◽  
Exact Expression ◽  
Gas Mixture ◽  
Binary Gas Mixture ◽  
Diffusion Slip

Slip Effects in Mixtures of Monatomic Gases for General Surface Accommodation

1975 ◽  
Vol 30 (6-7) ◽  
pp. 855-867 ◽  
Author(s):  
H. Lang ◽  
W. J. C. Müller
Keyword(s):  
Slip Velocity ◽  
Original Method ◽  
Anisotropic Surface ◽  
General Surface ◽  
Slip Effects ◽  
Binary Gas Mixture ◽  
Accommodation Coefficients ◽  
Diffusion Slip ◽  
Interaction Law ◽  
And Diffusion

Abstract Macroscopic slip velocity, macroscopic temperature jump, thermal creep velocity and diffusion slip velocity for a mixture of monatomic gases are calculated by using a method developed recently (modified Maxwell-method) for a general gas-gas and gas-surface interaction law, and for a possibly anisotropic surface. The results are expressed in terms of accommodation coefficients of first and second order. Specialization is made for a binary gas mixture. For a comparison the results obtained by Maxwell's original method and general surface accommodation are given. In the case of surface-anisotropy several new slip effects occur.

Diffusion Slip Velocity: Theory and Experiment

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1307-1319 ◽  
Author(s):  
H. Lang ◽  
S Loyalka
Keyword(s):  
Slip Velocity ◽  
Specular Reflection ◽  
Jones Potential ◽  
Lennard Jones ◽  
Binary Gas Mixture ◽  
Physical Insight ◽  
Diffusion Slip ◽  
Theoretical Results ◽  
Theory And Experiment ◽  
Variational Expression

Abstract A theoretical and experimental study of the phenomenon of diffusion slip in a binary gas mixture is presented. To provide some physical insight, a very general variational expression given earlier by Loyalka is rederived via the use of a method developed recently. The case of Maxwellian diffuse specular reflection is considered in some detail and the inadequacies of previous theoretical results based on the early arguments of Maxwell, kinetic models and simple intermolecular force laws are discussed. Although in general, the variational results (or the equivalent results given here) together with the assumptions of Lennard Jones potential and diffusive reflection give a satisfactory agreement with the available experimental data, it is found that for isobaric (isotopic) mixtures, in the choice of the intermolecular and gas-surface interaction parameters special care should be taken in that the results are quite sensitive to small variations in the values of these parameters.

On diffusion slip of a binary gas mixture

1974 ◽  
Vol 6 (4) ◽  
pp. 570-574 ◽  
Author(s):  
I. N. Ivchenko ◽  
Yu. I. Yalamov
Keyword(s):  
Gas Mixture ◽  
Binary Gas Mixture ◽  
Diffusion Slip

scholarly journals Influence of Casting Solvents on CO2/CH4 Separation Using Polysulfone Membranes

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 286
Author(s):  
Roba M. Almuhtaseb ◽  
Ahmed Awadallah-F ◽  
Shaheen A. Al-Muhtaseb ◽  
Majeda Khraisheh
Keyword(s):  
High Efficiency ◽  
In Situ Synthesis ◽  
Separation Process ◽  
Polymeric Membranes ◽  
Gas Mixture ◽  
Manufacturing Cost ◽  
Binary Gas Mixture ◽  
Maximum Permeability ◽  
Polysulfone Membranes

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

scholarly journals О бародиффузии при медленных течениях газовой смеси

2019 ◽  
Vol 89 (5) ◽  
pp. 646
Author(s):  
В.М. Жданов
Keyword(s):  
Equations Of Motion ◽  
Considerable Effect ◽  
Gas Mixture ◽  
Slip Coefficient ◽  
Knudsen Numbers ◽  
Slow Flows ◽  
Diffusion Slip ◽  
The Mean ◽  
The Individual ◽  
Small Knudsen Numbers

AbstractBarodiffusion in slow flows of a gas mixture is studied with an approximation using hydrodynamic equations of motion for the individual mixture components. It is shown that consideration of the viscous momentum transfer and the contribution of Knudsen layers for the mixture flowing in a channel has a considerable effect on the value of the barodiffusion factor. The relations are obtained for the mean diffusion fluxes of components and for the total flux of the mixture in a circular cylindrical capillary; these relations are valid for moderately small Knudsen numbers used for calculation of the diffusion baroeffect and separation effect when the gas mixture flows in a set of capillaries connecting two volumes. The modification of the relations for the barodiffusion factor (and for the diffusion slip coefficient cross-linked with it) allows interpreting the sign alteration of these effects observed experimentally for some gas mixtures at intermediate Knudsen numbers.

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