Oxygen mass transfer in bubble columns

Alvarez-Cuenca, M.; Baker, C. G. J.; Bergougnou, M.A.

doi:10.1016/0009-2509(80)85101-3

Cited by 29 publications

(18 citation statements)

References 14 publications

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“…They concluded that different mass transfer mechanisms exist in both the distributor and bulk zones. Some lateral variation in the C L values at a given axial position (z) was also observed by Alvarez-Cuenca et al (1980). The variation was more pronounced in the lower zone (LZ) and at lower u g .…”

Section: Randd Notementioning

confidence: 69%

“…Sometimes larger k L a values are observed in the distributor zone (Houghton et al, 1957;Deckwer et al, 1974Deckwer et al, , 1978Deckwer et al, , 1980 Buchholz et al, 1980;Herbrechtsmeier et al, 1981). Alvarez-Cuenca et al (1980) observed two distinct absorption zones (distributor and bulk zones) during mass transfer of oxygen (O 2 ) between air and water. High k L a values were observed in the distributor zone which extended up to a maximum height of about 5-15 % of the BB volume (Deckwer et al, 1974(Deckwer et al, , 1978.…”

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confidence: 99%

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Quality of Mixedness Profiles Based on Spatial Distribution of Local Mass Transfer Coefficients in a Bubble Column

Nedeltchev

Ogawa

2003

Can J Chem Eng

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G as-liquid bubble columns have a wide range of applications (absorption, catalytic slurry reactions, bioreactions, coal liquefaction, waste water treatment, etc.) because of their simplicity of operation, low operating costs, ease of maintenance and sufficiently high gas-liquid mass transfer rates. The satisfactory design of bubble columns invariably requires a knowledge of the volumetric liquid-phase mass transfer coefficient k L a which characterizes the rate of interfacial mass transfer and determines the amount of gas transferred from bubbles into the liquid. Two approaches have been used for k L a prediction: (1) separate correlations are obtained for the liquid-phase mass transfer coefficient, k L , and the interfacial area per unit volume, a, and (2) an empirical correlation is obtained for the overall k L a.In our previous papers (Nedeltchev et al., 1999(Nedeltchev et al., , 2000 we used the first approach and estimated k L by making use of both the classical penetration theory put forward by Higbie (1935) and the subsequent correction introduced by Miller (1974) for ellipsoidal bubbles. It will be shown, however, that the experimental local k L a values are different from the theoretical k L a value calculated by the penetration model. Only the arithmetic mean k L a value for the overall bubble bed (BB) is equal to the theoretical one.The present paper basically deals with the physical absorption of carbon dioxide (CO 2 ) in deionized water where the overall mass transfer coefficient is essentially equal to the liquid-phase mass transfer coefficient (Houghton et al., 1957;Hughmark, 1967;Hatton and Lightfoot, 1982;Lee and Tsui, 1999). Houghton et al. (1957) underlined that as much as 90 % of the entering CO 2 may be absorbed in a deep BB and hence the gas composition may change from 85 % down to 30 % CO 2 . Thus, the superficial gas velocity u g through the deep BB may vary considerably as absorption proceeds. The optimal design of bubble columns should take into account the variable u g since it influences almost all fluid dynamic properties (Deckwer, 1976 1978, 1980 Buchholz et al., 1980;Herbrechtsmeier et al., 1981). Alvarez-Cuenca et al. (1980) observed two distinct absorption zones (distributor and bulk zones) during mass transfer of oxygen (O 2 ) between air and water. High k L a values were observed in the distributor zone which extended up to a maximum height of about 5-15 % of the BB volume (Deckwer et al., 1974(Deckwer et al., , 1978. The bulk zone extended from the end of the distributor zone to the top of the BB. The axial liquid concentration C L gradients were much

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Section: Randd Notementioning

confidence: 69%

mentioning

confidence: 99%

Quality of Mixedness Profiles Based on Spatial Distribution of Local Mass Transfer Coefficients in a Bubble Column

Nedeltchev

Ogawa

2003

Can J Chem Eng

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“…The solution of Equations (1) and (2) is: This average ( L a ) , which was obtained using Equations (3) and (4) in conjunction with the experimental concentration profiles, is presented in Figures 2, 4, 5 and 6 as a function of V , and y. The discussion of these results is postponed to the following section.…”

Section: The Modelmentioning

confidence: 96%

The plug flow model for mass transfer in three‐phase fluidized beds and bubble columns

Alvarez-Cuenca

Nerenberg

1981

Can J Chem Eng

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The plug flow model (PFM), overwhelmingly used to describe mass transfer in bubble columns and three‐phase fluidized beds, has never been critically tested. This study analyzes the PFM single parameter, KLa, to quantify mass transfer in the forementioned systems. Particular attention is paid to the mass transfer features of the zone near the distributor (grid zone) largely ignored until now. This study, carried out under the largest gas and liquid flow rates ever published, for similar types of systems, indicates the presence of two well defined mass transfer zones. These features invalidate, for design purposes, the use of the PFM. However, it still can be used as a qualitative mass transfer indicator. This has permitted a comparison between the mass transfer efficiency of bubble columns and three‐phase fluidized beds with the conclusion that three‐phase fluidized bed of 0.5 cm particles can compete successfully with bubble columns.

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“…Researches on measuring and calculating height of gas distributor region have been rare, leading to great difficulties in defining the region. AlvarezCuenca et al [22] reported that, for superficial gas velocity less than 0.28 m/s and superficial liquid velocity of 0.25 m/s, the gas distributor region is less than 20 cm in height. In gas-liquid system, it can be clearly observed that the lower boundary of the feed affected region is about 190 mm to the exit of the feed tube.…”

Section: Apparatusmentioning

confidence: 98%

Region-dependent mass transfer behavior in a forced circulation airlift loop reactor

Liu¹,

Lu²,

Ming-xian³

et al. 2010

Powder Technology

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Oxygen mass transfer in bubble columns

Cited by 29 publications

References 14 publications

Quality of Mixedness Profiles Based on Spatial Distribution of Local Mass Transfer Coefficients in a Bubble Column

Quality of Mixedness Profiles Based on Spatial Distribution of Local Mass Transfer Coefficients in a Bubble Column

The plug flow model for mass transfer in three‐phase fluidized beds and bubble columns

Region-dependent mass transfer behavior in a forced circulation airlift loop reactor

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