Experimental Study of Liquid Dispersion in Bubble Column
Keywords:
Bubble column, axial dispersion, radial dispersion, gas hold-up, hydrodynamicsAbstract
The main object of this study is to investigate the influence of column diameter and superficial gas velocity on liquid phase dispersion coefficients (axial and radial dispersion coefficients), mixing times, gas holdup, and bubble dynamics (bubble diameter and rise velocity). The liquid phase dispersion, gas holdup, and bubble dynamics (Db and Vb0) were measured for the air-water system in bubble columns of two different diameters,15 and 30 cm. The superficial gas velocity, Ug, was varied in the range 1-10 cm/s, spanning both the homogeneous and heterogeneous flow regimes. The height of liquid in the column was kept constant at 130 cm for the two column. Axial and radial dispersion coefficients and mixing times were measured at various axial and radial locations inside the columns (Z = 25, 75, 125 cm and r/R = 0, 0.45, 0.85), bubble dynamics were measured at three axial location (Z=25, 75, 125 cm). From the experimental data it was found that, the value of the radial dispersion coefficient (Dr,L) and axial dispersion coefficient (Dax,L), gas holdup, bubble diameter and bubble rise velocity, increase with increasing superficial gas velocity. The results emphasise the significant influence of the column diameter on the hydrodynamics. Gas holdup showed a decrease with increasing column diameter, while the radial dispersion coefficient (Dr,L), axial dispersion coefficient (Dax,L), bubble diameter and bubble rise velocity increased with increasing column diameter. A statistical analysis was performed to get a general correlations for the axial liquid dispersion coefficient as a function of the mixing time and dispersion height (Hd), this correlations are: Dax,L=0.15 H2d /θ0.3 for 30 cm column diameter and Dax,L=0.11 H2d /θ0.3 for 15 cm column diameter.
Downloads
References
Koide K. "design parameters of bubble column reactors with and without solid suspensions" J. Chem. Eng. Japan, vol. 29, no. 5, 1996, 747-759
Forret A., J.-M. Schweitzer, T.Gauthier, R.Krishna and D.Schweich “liquid dispersion in large diameter bubble columns, with and without internals” Can J Chem Eng 81 (june-augest 2003) 360-366
Wild et al "some aspects of the hydrodynamics of bubble columns". International Journal of Chemical Reactor Engineering, 1 (2003) R.7, P.1
Deckwer W.-D. and Schumpe A. "Improved tools for bubble column design and scale up" Chem. Eng Sci., 48(5), (1993) 889-911
Derk J.Vermeer and Krishna R. “hydrodynamics and mass transfer in bubble columns operating in the churn-turbulent regime” Ind. Eng. Chem. Process Des. Dev. 20 (1981) 475-482
Deckwer W.-D. "bubble column reactors" John Wiley & sons, New York, 1992
F. Camacho Rubio, A. Sanchez Mirَon, M.C. Ceroَn Garcia, F. Garcia Camacho, E. Molina Grima,Y. Chisti. " Mixing in bubble columns: a newapproach for characterizing dispersion coefficients". Chem. Eng. Sci. 59 (2004) 4369-4376.
Levinspeil "Chemical Engineering Reaction" John Wiley & sons, New York, 1992
Krishna, R., M.I. Urseanu, J.M. van Baten, J. Ellenberger. Chem. Eng. J. 78 (2000) 43-51.
H.P. Riquarts, Strömungsprofile, Impulsaustausch and Durchmischung der flüssigen phase in Bläsemsaulen, Chem. Ing. Techn. 53 (1981) 60–61.
Joshi, J. B., & Sharma, M. M. (1979). Circulation cells model for bubble columns. Transactions of the Institute of Chemical Engineering, 57, 244-251.
Aoyama, Y., Ogushi, K., Koide, K. and Kubota, H., “Liquid Mixing in Concurrent Bubble Columns”, J. Chem. Eng. of Japan, 1, 158, (1968).
Hikita, H. and Kikukawa, H.,”Liquid-Phase Mixing in Bubble Columns: Effect of Liquid Properties”, Chem. Eng. J., 8, 191-197, (1974).
Riquarts, H. P., “A Physical Model for Axial Mixing of The Liquid Phase for Heterogeneous Flow Regime in Bubble Columns”, Ger. Chem. Eng., 4, 18-23, (1981).
Walter J. F. and Blanch, H. W., “Liquid Circulation Patterns and Their Effect on Gas Hold-up and Axial Mixing in Bubble Columns”, Chem. Eng. Commun., 19, 243-262, (1983).
K. Bernemann, 1989. Zur Fluiddynamik und zum Vermischungsverhalten der flüssigen Phase in Blasensäulen mit längsangeströmten Rohrbundeln, Ph.D. Thesis. University Dormund.
Konig, B., Buchholz, R., Lucke, J. and Schugerl, K., “Longitudinal Mixing of The Liquid Phase in Bubble Columns”, Ger. Chem. Eng. 1, 199, (1978).
Ohki, Y., Inoue, H., 1970. Longitudinal mixing of the liquid phase in bubble columns. Chemical Engineering Science 25, 1–16.
Towell, G.D., Ackerman, G.H., 1972. Axial mixing of liquid and gas in large bubble reactor. Proceedings of the Fifth European Second International Symposium on Chemical Reaction Engineering, vol. B3-1.
Blenke, H., 1979. Loop reactors. Advances in Biochemical Engineering 13, 121–214.
Field, R. W. and Davidson, J. F., “Axial Dispersion in Bubble Columns”, Trans. Inst. Chem. Eng., 58, 228-236, (1980).
Shah Y.T., B.G Kelkar, S.D.Godbole and W.-D.Deckwer "design parameter estimations for bubble column reactors" AICh E J., 28(3) (May 1982) 353-374
Molina Grima, E., Acién Fernandez, F.G., Garcia Camacho, F., Camacho Rubio, F., Chisti,Y., 2000. Scale-up of tubular photobioreactors. Journal of Applied Phycology 12, 355–368.
Sanchez Mirَon, A., Goَmez, A.C., Camacho, F.G., Grima, E.M., Chisti, Y., 1999. Comparative evaluation of compact photobioreactors for large-scale monoculture of microalgae. Journal of Biotechnology 70, 249–270.
Terry, K.L., 1986. Photosynthesis in modulated light: quantitative dependence of photosynthesis enhancement on flashing rate. Biotechnology Bioengineering 28, 988–995.
Camacho Rubio, F., Garcia Camacho, F., Fernandez Sevilla, J.M., Chisti, Y., Molina Grima, E., 2003. A mechanistic model of photosynthesis in microalgae. Biotechnology and Bioengineering 81, 459–473.
Hayder, M. A., "Liquid Dispersion in Bubble Column Using Air-Water System" M.Sc. Thesis University of Technology, Baghdad, 2007.
Kago T. et al "gas holdup and axial dispersion of gas and liquid in bubble columns of homogeneous flow regime" Chem. Eng. Comm. 75 (1989)23-38
Krishna, R. and Ellenberger, J. (1996) Gas Holdup in Bubble Column Reactors Operating in the Churn-Turbulent Flow Regime. AIChE J., 42, 2627-2634.
Kantarci N. et al " review: bubble column reactors" Process bio Chemistry 40 (2005) 2263-2283.
Wallis, G. B., “One-Dimensional Two-Phase Flow”, McGraw-Hill. New York, (1969).
Mouza A.A. et al “effect of liquid properties on the performance of bubble column reactors with fine pore spargers” Chem. Eng. Sci 60 (2005) 1465-1475.
Wei, F., Jin, Y., Yu, Z.Q., Chen, W., 1995. Lateral and axial mixing of the dispersed particles in CFB. Journal of Chemical Engineering Japan 28, 506–510.
Chen, W.,Yang, W., Wang, J., Jin,Y., Tsutsumi, A., 2001. Characterization of axial and radial liquid mixing in a liquid–solid circulating fluidized bed. Industrial & Engineering Chemistry Research 40, 5431–5435.
Krishna, R., Urseanu, M.I., Van Baten, J.M. and Ellenberger, J. (1999) Influence of Scale on the Hydrodynamics of Bubble Columns Operating in the Churn-Turbulent Regime: Experiments vs. Eulerian Simulations. Chem. Eng. Sci., 54, 4903-4911.
Krishna R. et al "scale effects on the hydrodynamics of bubble columns operating in the homogeneous flow regime" Chem. Eng. Technol, 24 (5), 2001, 451-458
Akita K. and Yoshida F. "gas holdup and volumetric mass transfer coefficient in bubble columns" Ind. Eng. Chem. Process Des. Dev. 112 (1973) 76-80
De Swart, J.W.A., van Vliet, R.E. and Krishna, R. (1996) Size, Structure and Dynamics of “Large” Bubbles in a 2-D Slurry Bubble Column. Chem. Eng. Sci., 51, 4619-4629.
Basalos, I. A., E. M. Bild, D. N. Rundel, and D. F. Tatterson, Coal Processing Tech., CEP Technical Manual 6, P. 226 (1980).
Koide K., S.Yamazoe and S.Harada "effect of surface-active substances on gas hold up and gas-liquid mass transfer in bubble columns" J. Chem. Eng. Japan, vol. 18, no. 4, 1985, 787
Yamashita F. "superficial rate of bubble break up in a bubble column" J. Chem. Eng. Japan, vol. 27, no. 5, 1994, 682-685
Onna Kramer "force acting on bubbles" 29 June 2000, university of Twente, the Netherlands, subject code "literature study": 139992
Krishna R. and van Bten J.M. "scaling up bubble column reactors with the aid of CFD" Trans IChem E, vol. 79, part A (April 2001) 283-309
Koide K., K.Muroyama, S.Morooka "behavior of bubbles in large scale bubble columns" J. Chem. Eng. Japan, vol. 12, (1979), 98-104
Lockett, M. J. and R. D. Kirkportick, Trans. Inst. Chem. Eng. 53, P. 267 (1975).
Kolbel, N. R., Beinhaner and H. Langeman, Chem. Eng. Tech. 44, P. 697 (1972).
Krishna R. (2000) "A Scale-up Strategy for a Commercial Scale Bubble Column Slurry Reactor for Fischer-Tropsch Synthesis" Oil & Gas Science and Technology, 55 (2000), No. 4, pp. 359-393
Pandit, A. B. and J. B. Joshy (1982). Chem. Eng. Sci. (Vol. 38, No. 8) 1189-1215, 1983
Whalley, P. B., Davidson J. F., “Proceeding Symposium on Multiphase Flow Systems”, Inst. Chem. Eng. Symp., Series No 38, Vol. 2, J5 (1974).
Field, R. W. and Davidson, J. F., “Axial Dispersion in Bubble Columns”, Trans. Inst. Chem. Eng., 58, 228-236, (1980).
Ueyama, K., Miyauchi, T., 1977. Behavior of bubbles and liquid in bubble column. Kagaku Kogaku Ronbunshu 3, 19–23.
Kawase, Y., Moo-Young, M., 1989b. Mixing time in bioreactors. Journal of Chemical Technology and Biotechnology 44, 63–75
J.B. Joshi, Axial mixing in multiphase contactors — a unified correlation, Trans. Inst. Chem. Engs. 58 (1980) 228–236.
Deckwer, W.-D., Burckhart, R., Zoll, G., 1974. Mixing and mass transfer in tall bubble columns. Chemical Engineering Science 29, 2177–2188.
J.B. Joshi, Axial mixing in multiphase contactors — a unified correlation, Trans. Inst. Chem. Engs. 58 (1980) 228–236.
Published
How to Cite
Issue
Section
Copyright (c) 2008 Hayder Abd Al-kaream Muhsin, Mohammad Fadhil Abid
This work is licensed under a Creative Commons Attribution 4.0 International License.
