CFD Simulation of Flow and Mass Transfer in Structured Packing Distillation Columns

Abstract

Abstract: Detailed investigation of flow behavior in structured packing distillation columns is of great importance in accurate prediction of process efficiency and development of more efficient and optimal equipment internals. In this study, a three-dimensional two-phase flow model based on VOF method for simulating the hydrodynamics and mass-transfer behavior in a typical representative unit of the structured packing is developed. In the proposed model, the c²-ε_c model is used for the closure of turbulent mass transfer equation. By solving the proposed model, the velocity distribution, phase fraction profile and concentration field are obtained. Using these data, the total liquid holdup, the wetted area and the separation efficiency [height equivalent to a theoretical plate (HETP)] are estimated. For testing the model validation, the simulated HETPs are compared with our previous experimental data obtained in a 150 mm-diameter column containing Mellapak 350Y operating at the pressures of 0.6-1.8 MPa. The comparison shows that they are in satisfactory agreement, with an average absolute deviation (AAD) of 25.4%.

Key words: structured packing, two-phase flow model, mass transfer, height equivalent to a theoretical plate

摘要： Detailed investigation of flow behavior in structured packing distillation columns is of great importance in accurate prediction of process efficiency and development of more efficient and optimal equipment internals. In this study, a three-dimensional two-phase flow model based on VOF method for simulating the hydrodynamics and mass-transfer behavior in a typical representative unit of the structured packing is developed. In the proposed model, the c²-ε_c model is used for the closure of turbulent mass transfer equation. By solving the proposed model, the velocity distribution, phase fraction profile and concentration field are obtained. Using these data, the total liquid holdup, the wetted area and the separation efficiency [height equivalent to a theoretical plate (HETP)] are estimated. For testing the model validation, the simulated HETPs are compared with our previous experimental data obtained in a 150 mm-diameter column containing Mellapak 350Y operating at the pressures of 0.6-1.8 MPa. The comparison shows that they are in satisfactory agreement, with an average absolute deviation (AAD) of 25.4%.

关键词: structured packing, two-phase flow model, mass transfer, height equivalent to a theoretical plate

CHEN Jiangbo, LIU Chunjiang, YUAN Xigang, YU Guocong. CFD Simulation of Flow and Mass Transfer in Structured Packing Distillation Columns[J]. , 2009, 17(3): 381-388.

陈江波, 刘春江, 袁希钢, 余国琮. CFD Simulation of Flow and Mass Transfer in Structured Packing Distillation Columns[J]. CIESC Journal, 2009, 17(3): 381-388.

References

1 Hodson, J.S., Fletcher, J.R., Porter K.E., “Fluid mechanical studies of structured distillation packings”, Ins. Chem. Eng. Symp. Ser., Dist. Absorp.,(142), 999-1007(1997).
2 van Gulijk, C., “Using computational fluid dynamics to calculate transversal dispersion in a structured packed bed”, Comput. Chem. Eng., 22, S767-S770(1998).
3 van Baten, J.M., Krishna, R., “Liquid-phase mass transfer within KATAPAK-S structures studied using computational fluid dynamics simulations”, Catalysis Today, 69, 371-377(2001).
4 van Baten, J.M., Ellenberger, J., Krishna, R., “Radial and axial dispersion of the liquid phase within a KATAPAK-S structure:experiments vs. CFD simulations”, Chem. Eng. Sci., 56, 813-821(2001).
5 van Baten, J.M., Krishna, R., “Gas and liquid phase mass transfer within KATAPAK-S structures studied using CFD simulations”, Chem. Eng. Sci., 57, 1531-1536(2002).
6 Kl ker, M., Kenig, E.Y., Gorak, A., “On the development of new column internals for reactive separations via integration of CFD and process simulation”, Catalysis Today, 79(1-4), 479-485(2003).
7 Kl ker, M., Kenig, E.Y., Piechoia, R., Burghoff, S., Egorov, Y., “CFD-based study on hydrodynamics and mass transfer in fixed catalyst beds”, Chem. Eng. Technol., 28(1), 31-36(2005).
8 Egorov, Y., Menter, F., Kloker, M., Kenig, E.Y., “On the combination of CFD and rate-based modelling in the simulation of reactive separation processes”, Chem. Eng. Process., 44(6), 631-644(2005).
9 Petre, C.F., Larachi, F., Iliuta, I., Grandjean, B.P.A., “Pressure drop through structured packings:breakdown into the contributing mechanisms by CFD modeling”, Chem. Eng. Sci., 58, 163-177(2003).
10 Larachi, F., Petre, C.F., Iliuta, I., Grandjean, B., “Tailoring the pressure drop of structured packings through CFD simulations”, Chem. Eng. Process., 42, 535-541(2003).
11 Raynal, L., Boyer, C., Ballaguet, J.P., “Liquid holdup and pressure drop determination in structured packing with CFD simulations”, The Canadian Journal of Chemical Engineering, 82, 871-879(2004).
12 Zhang, P., “Experimental studies and CFD simulations of fluid flow and mass transfer in a structured packed column at elevated pressure”, Ph.D. Thesis, Tianjin University, Tianjin(2002).(in Chinese)
13 Zhang, P., Liu, C.J., Yuan, X.G., Yu, K.T., “CFD simulations of liquid phase flow in structured packed column”, J. Chem. Ind. Eng.(China), 55(8), 1369-1373(2004).(in Chinese)
14 Iliuta, I., Larachi, F., “Mechanistic model for structured-packing containing columns:irrigated pressure drop, liquid holdup and packing fractional wetted area”, Ind. Eng. Chem. Res., 40, 5140-5146(2001).
15 Iliuta, I., Petre, C.F., Larachi, F., “Hydrodynamic continuum model for two-phase flow structured-packing-containing columns”, Chem. Eng. Sci., 59, 879-888(2004).
16 Yin, F.H., Sun, C.G., Afacan, A., Nandakumar, K., Chuang, K.T., “CFD modeling of mass-transfer processes in randomly packed distillation columns”, Ind. Eng. Chem. Res., 39,1369-1380(2000).
17 Yin, F., Afacan, A., Nandakumar, K., Chuang, K.T., “Liquid holdup distribution in packed columns:gamma ray tomography and CFD simulation”, Chem. Eng. Process., 41, 473-483(2002).
18 Jiang, Y., Khadilkar, M.R., Al-Dahhan, M.H., Dudukovic, M.P., “CFD of multiphase flow in packedbed reactors:1. k-Fluid modeling issues”, AIChE J., 48(4), 701-715(2002).
19 Jiang, Y., Khadilkar, M.R., Al-Dahhan, M.H., Dudukovic, M.P., “CFD of multiphase flow in packed-bed reactors:2. Results and applications”, AIChE J., 48(4), 716-730(2002).
20 Yuan, Y.H., Han, M.H., Cheng, Y., Wang, D., Jin, Y., “Experimental and CFD analysis of two-phase cross/countercurrent flow in the packed column with a novel internal”, Chem. Eng. Sci., 60(22), 6210-6216(2005).
21 Szulczewska, B., Zbicinski, I., Gorak, I., “Liquid flow on structured packing:CFD simulation and experimental study”, Chem. Eng. Technol., 26(5), 580-584(2003).
22 Gu, F., Liu, C.J., Yuan, X.G., Yu K.T., “CFD simulation of liquid film flow on inclined plates”, Chem. Eng. Technol., 27(10), 1099-1104(2004).
23 Gu, F., “CFD Simulations of the local-flow and mass-transfer in the structured packing”, Ph.D. Thesis, Tianjin University, Tianjin(2004).(in Chinese)
24 Hoffmann, A., Ausner, J., Repke, J.U., Wozny, G., “Fluid dynamics in multiphase distillation processes in packed towers”, Comput. Chem. Eng., 29(6), 1433-1437(2005).
25 Valluri, P., “Multiphase fluid dynamics in structured packings”, Ph.D. Thesis, Imperial College London, University of London(2004).
26 Valluri, P., Matar, O.K., Hewitt, G.F., Mendes, M.A., “Thin film flow over structured packings at moderate Reynolds numbers”, Chem. Eng. Sci., 60, 1965-1975(2005).
27 Ataki, A., Bart, H.J., “Experimental and CFD simulation study for the wetting of a structured packing element with liquids”, Chem. Eng. Technol., 29(3), 336-347(2006).
28 Chen, J.B., Tang, Z.L., Wang, G.Q., Liu, C.J., Yuan, X.G., Yu, G.C., “Performance of Mellapak 350Y corrugated sheet structured packing at elevated pressure”, J. Chem. Ind. Eng.(China), 55(2), 335-336(2004).(in Chinese)
29 Chen, J.B., “Numerical and experimental study of transport phenomena in a structured packed column at high pressure”, Ph.D. Thesis, Tianjin University, Tianjin(2006).(in Chinese)
30 Liu, B.T., “Study of a new mass transfer model of CFD and its application on distillation tray”, Ph.D. Thesis, Tianjin University, Tianjin(2003).(in Chinese)
31 Zhang, Z.S., Turbulence, National Defense Industry Press, Beijing(2002).(in Chinese)
32 Rocha, J.A., Bravo, J.L., Fair, J.R., “Distillation columns containing structured packings:A comprehensive model for their performance. 2. Mass transfer model”, Ind. Eng. Chem. Res., 35, 1660-1667(1996).
33 Gualito, J.J., Cerino, F.J., Cardenas, J.C., Rocha, J.A., “Design method for distillation columns filled with metallic ceramic, or plastic structured packings”, Ind. Eng. Chem. Res., 36, 1747-1757(1997).
34 Fluent Inc., User’s Guide of Fluent 6.0, Lebanon(2001).

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