Bubbles absorption from

Coppock and Meiklejohn (C9) determined liquid mass-transfer coefficients for the absorption of oxygen in water. The value of k, was observed to vary markedly with variations of bubble velocity, from 0.028 to 0.055 cm/sec for a velocity range from 22 to 28 cm/sec. These results appear to be in general agreement with the results obtained by Datta et al. (D2) and by Guyer and Pfister (G9) for the absorption of carbon dioxide by water. 

Pasveer (PI) studied oxygen absorption from air bubbles by water and found that the experimental results could be adequately correlated in terms of a penetration or surface-renewal theory. 

Note added in proof A comprehensive review on gas absorption from bubbles has recently been published by P. H. Calderbank, Trans. Inst. Chem. Engrs. (London), Chem. Eng. 209 (1967). 

Emmert and Pigford (E2) have studied the reaction between carbon dioxide and aqueous solutions of monoethanolamine (MEA) and report that the reaction rate constant is 5400 liter/mole sec at 25°C. If it is assumed that MEA is present in excess, the reaction may be treated as pseudo first-order. This pseudo first-order reaction has been recently used by Johnson et al. (J4) to study the rate of absorption from single carbon dioxide bubbles under forced convection conditions, and the results were compared with their theoretical model. 

In studying gas absorption from single bubbles, Hammerton and Gamer (H7) clearly demonstrated that contamination of the surface of a rising bubble by surface-active material initially present in trace amount can convert a... 

P. G. Ledig, the rate of absorption from gas-bubbles. E. B. Auerbach and L. Millbradt compared the rates of escape of ammonia and water from aq. soln. They found that the loss from soln. with 34-5, 25-7, and 22-7 per cent, of ammonia was respectively 28-3, 194, and 164 per cent., while only one to two per cent, of water was lost—vide swpra. 

Absorption from the gas phase into the liquid phase at the bubble surface... 

Calderbank PH. Gas absorption from bubbles. Chemical Engineer (London) 45(211) CE209-CE253, 1967. 

Wimmers et al. [144,145] measured the enhancement of absorption from a stationary bubble into a stagnant liquid catalyzed by fine activated carbon and arrived, both experimentally and theoretically, at ... 

O ConneU s correlations for bubble-cap trays (a) distillation (b) absorption. (From O Connell, H.E., Trans. Am. Inst. Chem. Engrs., 42, 741, 1946. With permission.)... 

Recovery of Ammonia. The filter Hquor contains unreacted sodium chloride and substantially all the ammonia with which the brine was originally saturated. The ammonia may be fixed or free. Fixed ammonia (ammonium chloride [12125-02-97]) corresponds stoichiometrically to the precipitated sodium bicarbonate. Free ammonia includes salts such as ammonium hydroxide, bicarbonate, and carbonate, and the several possible carbon—ammonia compounds that decompose at moderate temperatures. A sulfide solution may be added to the filter Hquor for corrosion protection. The sulfide is distilled for eventual absorption by the brine in the absorber. As the filter Hquor enters the distiller, it is preheated by indirect contact with departing gases. The warmed Hquor enters the main coke, tile, or bubble cap-fiUed sections of the distiller where heat decomposes the free ammonium compounds and steam strips the ammonia and carbon dioxide from the solution. 

Absorption recovers valuable light components such as propane/propylene and butane/ butylene as vapors from fractionating columns. These vapors are bubbled through an absorption fluid, such as kerosene or heavy naphtha, in a fractionating-like column to dissolve in the oil while gases, such as hydrogen, methane, ethane, and ethylene, pass through. Absorption is effectively performed at 100 to 150 psi with absorber heated and distilled. The gas fraction is condensed as liquefied petroleum gas (LPG). The liquid fraction is reused in the absorption tower. 

Yoshida and Akita (Yl) determined volumetric mass-transfer coefficients for the absorption of oxygen by aqueous sodium sulfite solutions in counter-current-ffow bubble-columns. Columns of various diameters (from 7.7 to 60.0 cm) and liquid heights (from 90 to 350 cm) were used in order to examine the effects of equipment size. The volumetric absorption coefficient reportedly increases with increasing gas velocity over the entire range investigated (up to approximately 30 cm/sec nominal velocity), and with increasing column diameter, but is independent of liquid height. These observations are somewhat at variance with those of other workers. 

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