CFD Simulations to Validate Two and Three Phase Up-flow in Bubble Columns

Authors: Shyam Kumar, Nannuri Srinivasulu, Ashok Khanna

Abstract:

Bubble columns have a variety of applications in absorption, bio-reactions, catalytic slurry reactions, and coal liquefaction; because they are simple to operate, provide good heat and mass transfer, having less operational cost. The use of Computational Fluid Dynamics (CFD) for bubble column becomes important, since it can describe the fluid hydrodynamics on both local and global scale. Euler- Euler two-phase fluid model has been used to simulate two-phase (air and water) transient up-flow in bubble column (15cm diameter) using FLUENT6.3. These simulations and experiments were operated over a range of superficial gas velocities in the bubbly flow and churn turbulent regime (1 to16 cm/s) at ambient conditions. Liquid velocity was varied from 0 to 16cm/s. The turbulence in the liquid phase is described using the standard k-ε model. The interactions between the two phases are described through drag coefficient formulations (Schiller Neumann). The objectives are to validate CFD simulations with experimental data, and to obtain grid-independent numerical solutions. Quantitatively good agreements are obtained between experimental data for hold-up and simulation values. Axial liquid velocity profiles and gas holdup profiles were also obtained for the simulation.

Keywords: Bubble column, Computational fluid dynamics, Gas holdup profile, k-ε model.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1080538

References:

[1] J. Schallenberg, J. H. Enß, D. C. Hempel, "The important role of local dispersed phase holdups for the calculation of three-phase bubble columns," Chemical Engineering Science, vol. 60, pp. 6027-6033, 2005.
[2] W. D. Deckwer, "Bubble Column Reactors," Wiley, New York, 1992.
[3] Y. T. Shah, S. P. Godbole, W. D. Deckwer, "Design parameters estimations for bubble column reactors," AIChE Journal, vol. 28, pp. 353-379, 1982.
[4] H. Li, A. Prakash, "Heat transfer and hydrodynamics in a three-phase slurry bubble column" Ind Eng Chem Res, vol. 36, pp. 4688-4694, 1997.
[5] W. D. Deckwer, A. Schumpe, "Improved tools for bubble column reactor design and scale-up," Chemical Engineering Science, vol. 48, pp. 889-911, 1993.
[6] X. Luo, D. J. Lee, R. Lau, G. Yang, L. Fan, "Maximum stable bubble size and gas holdup in high-pressure slurry bubble columns," AIChE Journal, vol. 45 pp. 665-685, 1999.
[7] G. Eigenberger, A. Sokolichin, "Applicability of the standard k-╬Á turbulence model to the dynamic simulation of bubble columns. part i. detailed numerical simulations," Chemical Engineering Science, vol. 54, pp. 2273-2284, 1999.
[8] V. V. Ranade, V. V. Buwa, "Characterization of dynamics of gas-liquid flows in rectangular bubble columns," AIChE Journal, vol. 50, pp. 2394- 2407, 2004.
[9] A. Sokolichin, G. Eigenberger, O. Borchers, C. Busch, "Applicability of the standard kepsilon turbulence model to the dynamic simulation of bubble columns. part ii. Comparison of detailed experiments and flow simulations," Chemical Engineering Science, vol. 54, pp. 5927-5935, 1999.
[10] K. Bech, "Dynamic simulation of a 2d bubble column," Chemical Engineering Science, vol. 60, pp. 5294-5304, 2005.
[11] N. Gilbert, H.G. Wagner, D. Peger, S. Gomes, "Hydrodynamic simulations of laboratory scale bubble columns fundamental studies of the eulerian-eulerian modeling approach," Chemical Engineering Science, vol. 54, pp. 5091-5099, 1999.
[12] M. I. Urseanu R. Krishna, J.M. van Baten, "Three-phase eulerian simulations of bubble column reactors operating in the churn-turbulent regime: a scale up strategy," Chemical Engineering Science, vol. 55, pp. 3275-3286, 2000.
[13] M. Chang, Y. Pan, M. P. Dudukovic, "Dynamic simulation of bubbly flow in bubble columns," Chemical Engineering Science, vol. 54, pp. 2481-2499, 1999.
[14] V. V. Ranade, V. V. Buwa, D.S. Deo, "Eulerianlagrangian simulations of unsteady gasliquid flows in bubble columns" Int. J. Multiphase Flow, vol. 32, pp. 864-885, 2006.
[15] J. A. M. Kuipers, W .P. M. van Swaaij, E. Delnoij, F. A. Lammers, "Dynamic simulation of dispersed gas-liquid two-phase flow using a discrete bubble model," Chemical Engineering Science, vol. 52, pp. 1429-1458, 1997.
[16] J. A. M. Kuipers, D. Darmana, N. G. Deen. "Detailed modeling of hydrodynamics, mass transfer and chemical reactions in a bubble column using a discrete bubble model," Chemical Engineering Science, vol 60, pp. 3383-3404, 2005.
[17] A. Lobbert, A. Lapin, "Numerical simulation of the dynamics of twophase gas-liquid flows in bubble columns," Chemical Engineering Science, vol. 49, pp.3661-3674, 1994.
[18] O. Simonin, R. F.Mudde, "Two- and three-dimensional simulations of a bubble plume using a two-fluid model," Chemical Engineering Science, vol. 54, pp. 5061-5099, 1999.
[19] A. Lapin A. Liibbert A. Sokolichin, G. Eigenberger, "Dynamic numerical simulation of gas-liquid two-phase flows euler/euler Vs euler/lagrange," Chemical Engineering Science, vol. 49, pp. 3661-3674, 1997.
[20] H. D. Mandelson, "The prediction of bubble terminal velocities from wave theory," AIChE Journal, vol. 13, pp. 250, 1967.
[21] J. P. Vandoormaal, G. D. Raithby, "Enhancements of the SIMPLE Method for Predicting Incompressible Fluid Flows," Numer. Heat Transfer, vol. 7, pp. 147-163, 1984.
[22] Z. Naumann, L. Schiller, "A drag coefficient correlation," Z. Ver Deutsch.Ing, vol. 77, pp. 318-323, 1935.
[23] D. Z. Zhang, W. B. Vanderheyden, "The effects of meso-scale structures on dispersed two-phase flows and their closures in dilute suspensions," International Journal of Multiphase Flow, vol. 28, pp. 805, 2002.
[24] A. Tomiyama, H. Tamai, I. Zun, and S. Hosokawa, "Transverse migration of single bubbles in simple shear flows," Chemical Engineering Science, vol. 57, pp. 1849-1858, 2002.
[25] R. Krishna, J.M. van Baten, J. Ellenberger, "Scale-up strategy for bubble column slurry reactors using cfd simulations," Catalysis Today, vol. 79- 80, pp. 259-265, 2003.
[26] M. P. Dudukovic, N. Rados, M. H. Al-Dahhan, "Dynamic modelling of slurry bubble column reactors," Ind. Eng. Chem. Res., vol. 44, pp. 6086- 6094, 2005.
[27] F. Zdravistch, A. A. Troshko, "Cfd modelling of slurry bubble column reactors for fisher-tropsh synthesis," Chemical Engineering Science, vol. 64, pp. 1892-1903, 2009.
[28] W. Feng, J. Wen, J. Fan, Q. Yuan, X. Jia, Y. Sun, "Local hydrodynamics of gas-liquid-nano particles three-phase fluidization," Chemical Engineering Science, vol. 60, pp. 6887-6898, 2005.
[29] G. Hillmer, L. Weismantel, H. Halfmann, "Investigations and modelling of slurry bubble columns," Chemical Engineering Science, vol. 49, pp. 837-843, 1993.