Effect of Adding Alcohols and Gas Velocity on Gas Hold up and Mass Transfer Coefficient in Bubble Columns with Draught Tube
Abstract
The bubble columns are widely used as a two or three phase reactor in industrial chemical process such as absorption, biochemical reactions, coal liquefaction, etc. To design such a column, two main parameters should be taken in consideration, the gas hold-up (), and the liquid phase mass transfer coefficient KLa. The study includes the effect of gas velocity and the addition of alcohols on gas hold-up and mass transfer coefficient in bubble column with draught tube when the length of the column is 1.5m and the ratio of the draught tube diameter to the column diameter equals 0.5 and the air dispersion into the base of the draught tube using a multi hole tuyere is equivalent to a diameter of 0.15 mm and has a free sectional distributor area of 61%.
Water and three aqueous solutions of 10% concentration methanol, ethanol and isopropanol, were used as the liquid phase. The various gas velocity (0.01-0.1) meter/sec are used and the results were compared in case of using water only without the addition of alcohols. From experimental observations, and KLa increase with increasing gas velocity and with the coalescence inhibition of liquid.
Downloads
References
[2] Alvarez-cunca, M., and M. A. Nerenbreg, “Oxygen Mass Transfer in Bubble Columns Working at an Liquid Flow Rates”, AICHEJ., 27, 66 (1980).
[3] Brennan, R., D., Cosserat and J. C. Carpentier, “Influence of column diameters of high gas through puts on the operation of a bubble column”, the chemical engineering journal, 16, 115 (1978).
[4] Burekhart, R., and W. D. Deckwer, “Bubble size distribution and interfacial areas of electrolyte solutions in bubble columns” chem.. eng. sci, 30, 351 (1976).
[5] Calderbank, P. H., chemical engineer, 45, 225 (1976) (Kara et al 1982).
[6] Deckwer, W. D., Burckhart, R. and zoll, G., “mixing and mass transfer in tall bubble columns” chem.. eng. sci. 29, 2177-2188 (1974).
[7] Franz , K., Borner, T., Kantorek, H. J. and Buchholz, R., “flow structures in bubble columns”, Ger. chem. eng., 365-374 (1984).
[8] Godbole, S. P., Schumpe, A., Shah, Y.T. and carr, N.L., “Hyrodynamics and mass transfer in non-newtonian solutions in a bubble column”, AICHE J., 30 (20) 213-220 (1984).
[9] Guy C., Carreau, P. J. and paris, J., “Mixing characteristics and gas hold-up of bubble column” can.S. chem..eng. 64(2), 23-35 (1986).
[10] Hyndman, C.L., Larachi F, Gay C. “Understanding gas-phase hydrodynamics in bubble columns”, chem.. eng. sci 52, 63-77 (1997).
[11] Kawagoe, K., Inoue, T., Nakao. “Flow-Pattern and gas hold-up conditions in gas-sparged contactors” int. J. Chem. eng. 16, (176-183) (1976).
[12] Koide, K., Takazawa, A., Komura, M. and Matsunage, H. “Gas hold-up of volumetric liquid phase mass transfer in solid suspended bubble columns”, J. Chem. Eng. Japan, 17 (5) 459- 466 (1984).
[13] Maclean, G.F., L. E. Erickson, K. H. Hsu, and L. T. Fan, “oxygen transfer and axial desperation in an aeration tower containing Static mixers”, Biotechn. Bioengng. 19, 493 (1977).
[14] Mangertz, K. H., and Pilhofer, “Interpretation of mass transfer measurements in bubble columns considering desperation of both phases”, chem.. eng. sci., 36, 1069 (1981).
[15] Mashelkar, R.A., and M.M. Sharma, “Mass transfer in bubble columns”, trans. inst. chem. eng., 48, T162 (1970).
[16] Pandit, A.B. and Joshi, J.B., “Mixing in mechanically agitated gas liquid contactors, bubble columns and modified bubble columns”, chem. eng. sci., 8, 1189-1215 (1982).
[17] Pandit, A.B. and Joshi, J.B., “Three phase sparged reactions, some design aspects”, Rev. chem. eng., 2, 1-84 (1984).
[18] Schumpe, A., Grund, G. “The gas disengagement technique for studying gas hold-up structure in bubble column”, can. J. Chem. Eng. 64, (891-896) (1986).
[19] Schugerl, K., J. Lucke, and U. Oels, “bubble column bioreactions”, Adv. Biochem. eng., ed., T. K. Ghose, A. Fiechter, and N. Blakeborogh, 7, 1 (1977).
[20] Shah, Y. T., Kelkar, B. G., Godbole, S. P. and Deckwer, W. D., “Design parameters estimation for bubble column reactors”, AICHE, J., 28 (3), 353-379(1982).
[21] Shiaya, S., and I. J. Duna, “Dynamic oxygen mass transfer coefficient measurement method for column reactors”, chem.. eng. sci., 33, 1529 (1978).
[22] Thorat, B. N., Joshi, J. B., “Regime transition in bubble columns”, sci 28, 423-430 (2004).
[23] Urza, I. J., and Jackson, “pressure aeration in a 55-ft bubble column”, ind. eng. chem. process des. dev., 14, 106 (1975).
[24] Wu, Y., Ong, B. J., AL-Dahhan, M. H. “Prediction of gas hold-up profiles in bubble column reactors”, chem. eng. sci., 30, 1207-1210 (2001).
Downloads
Published
Issue
Section
License
Copyright: Open Access authors retain the copyrights of their papers, and all open access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited. The use of general descriptive names, trade names, trademarks, and so forth in this publication, even if not specifically identified, does not imply that these names are not protected by the relevant laws and regulations. While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.
