9 research outputs found

    Pattern formation outside of equilibrium

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    CO2 capture in HFMM contactor with typical amine solutions: A numerical analysis

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    International audienceThe absorption behavior of carbon dioxide using a hollow fiber membrane contactor was numerically analyzed. In this analysis, the absorbent solution is flowing in the inner side of the fiber bore and the pure gas in the shell and the module operated in a non-wetted mode. The derived coupled non-linear govern- ing partial differential equations were numerically solved by the orthogonal collocation technique. Three typical alkanolamines of industrial use, the diethanolamine (DEA), the 2-amino-2-methyl-1-propanol(AMP), and the diisopropanolamine( DIPA)were used as absorbents in this work. One important feature of this study was building the mathematical model based on the two-step carbamate formation model instead of the one-step model used by previous investigators. The outlet absorbed dioxide concentration was simulated and studied with respect to the liquid velocity, initial amine concentration and external mass transfer coefficient. The analysis includes the effects of the diameter and length of the fibers on the liquid outlet gas concentration as a function of the liquid velocity in the fiber. Simulation results show that AMP solutions present a much higher absorption capacity compared to the other two amines olutions

    Hollow Fiber Membrane Contactor for Hydrogen Sulfide Odor Control

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    International audienceHollow 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 Leveque semianalytical solution

    An Insight Into the Production, Characterization, and Mechanisms of Action of Low-Cost Adsorbents for Removal of Organics From Aqueous Solution

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