Mass transport in the membrane air-stripping process using microporous polypropylene hollow fibers: effect of toluene in aqueous feed

Mahmud, Hassan; Kumar, Ashwani; Narbaitz, Roberto; Matsuura, Takeshi

doi:10.1016/s0376-7388(02)00320-4

Cited by 41 publications

(22 citation statements)

References 34 publications

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“…In general, the pores that are filled by water, gas or both depend on the operating pressure, surface tension and contact angle between the two phases as reported by Mahmud et al 19 …”

mentioning

confidence: 84%

Hollow fiber membrane contactor for hydrogen sulfide odor control

et al. 2007

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Hollow fiber membrane modules are extensively used as gas–liquid contactors for acid gas removal from waste gas streams. Hydrogen sulfide is an important indoor and outdoor contaminant, but, given its toxicity, a limited number of experimental results have been reported for this compound. Moreover, chemical absorption has been exclusively investigated. In this study, hydrogen sulfide odor control by absorption in water thanks to a hollow fiber contactor has been studied both experimentally and theoretically. The scrubbing of hydrogen sulfide from air gas mixture is investigated in two porous polypropylene (PP) hollow fiber modules of different contact area and fiber packing fraction. The gas phase is circulated in the lumen of the fiber bore and the liquid phase in the shell in a nonwetted mode, i.e. the membrane pores being filled with gas. The gas phase was run in countercurrent contact with the liquid phase at constant pressure. A laminar parabolic velocity has been employed to describe the convective diffusive mass transport equation which has been solved analytically and numerically. The calculated extents of hydrogen sulfide depletion reasonably compare with the generated experimental results for both membrane modules. Up to 85% of acid gas could be removed at gaseous flowrates of 200 cm3/min for the large module and removals as high as 89% at 10 cm3/min have been observed for the smaller one. The overall mass transfer coefficients calculated from the experimental data, agree satisfactorily with those generated by the mathematical model. The relation of the dimensionless Sherwood number to the Graetz number is in a good agreement with the Levêque semianalytical solution. © 2007 American Institute of Chemical Engineers AIChE J, 54: 122–131, 2008

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“…In general, the pores that are filled by water, gas or both depend on the operating pressure, surface tension and contact angle between the two phases as reported by Mahmud et al 19 …”

mentioning

confidence: 84%

Hollow fiber membrane contactor for hydrogen sulfide odor control

et al. 2007

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“…The difference between membrane evaporation and MD is in that membrane evaporation is used for the concentration of thermo-sensitive solutions [6][7][8], while MD aims to obtain high quality water from the vapor [4,5]. Therefore, there is no need to recover the water vapor on the permeate side in membrane evaporation.…”

Section: Introductionmentioning

confidence: 99%

Condensation studies in membrane evaporation and sweeping gas membrane distillation

Zhao

Feron

Xie

et al. 2014

Journal of Membrane Science

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Vapor transfer is an important phenomenon in various thermally driven membrane processes such as membrane distillation (MD), membrane evaporation and membrane condensation. In this study, we explore the mass transfer phenomena in sweeping gas membrane distillation (SGMD) by systematically investigating the effects of operational parameters on the process performance. It is found that mass transfer in SGMD is principally determined by both the evaporation temperature and the sweeping gas flow rate, and is significantly influenced by the operational parameters (i.e. fluid velocities) through multiple effects, including the boundary layer effect on both sides of the membrane, and the temperature polarization effect. We also prove that at low gas flow rates (i.e. insufficient gas vapor-holding capacity) the sweeping gas becomes saturated and water vapor forms droplets due to condensation on the gas side of the membrane. To the best of our knowledge, this is the first study reporting the interesting mass transfer phenomena in terms of vapor condensation and droplet re-evaporation in SGMD, which are of great significance for the heat and mass transfer in many thermally driven membrane processes using stripping gas.

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“…Studies pertinent to this topic, especially to the removal of volatile component from water or wastewater, have been widely conducted, and many volatile compounds, such as ammonia [1][2][3], chloroform [4][5][6], toluene, phenol, o-xylene [6][7], trichloroethylene [8], were tested in these studies. Usually, the permeated components are discharged out of the membrane module either by means of sweeping gas, or using some solvent, which may react very quickly with the permeated components.…”

Section: Introductionmentioning

confidence: 99%