Convective mass transfer of a binary gas mixture in an inclined channel

Author(s):  
Vladimir Kossov ◽  
Olga Fedorenko ◽  
Dauren Zhakebayev ◽  
Venera Mukamedenkyzy ◽  
Dyusembek Kulzhanov
Author(s):  
Athanasios I Liapis ◽  
Jee-Ching Wang ◽  
Roberto Bruttini

A thermodynamic model employing the UNIFAC (Dortmund) method was developed to determine the currently unavailable partial vapor pressures of the binary gas mixture of water and tert-butyl alcohol (TBA) in equilibrium with their frozen solid mixtures. The results agree satisfactorily with the experimental data and indicate that TBA has higher vapor pressures which lead to higher total pressures at the moving interface that could result in larger total pressure gradients and convective mass transfer rates in the dried layer during primary drying. But the higher total pressures reduce the magnitude of the bulk diffusivity of the gas mixture and combined with the smaller Knudsen diffusivity of TBA could significantly impact the competing mass transfer mechanisms during freeze drying.   Keywords: Freeze drying; Water and tert-butyl alcohol (TBA); UNIFAC (Dortmund); Partial vapor pressures; Convective flow and bulk and Knudsen diffusion


2007 ◽  
Vol 10 (3) ◽  
pp. 277-286 ◽  
Author(s):  
Martin J. Garland ◽  
S. U. Rahman ◽  
K. A. Mahgoub ◽  
Ahmad Nafees

2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.


2017 ◽  
Vol 2 (11) ◽  
Author(s):  
Jerome Duplat ◽  
Mathieu Grandemange ◽  
Cedric Poulain

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 286
Author(s):  
Roba M. Almuhtaseb ◽  
Ahmed Awadallah-F ◽  
Shaheen A. Al-Muhtaseb ◽  
Majeda Khraisheh

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.


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