Abstract
Buoyancy-induced mixing occurs during expanded bed adsorption processes when the feed stream entering the bottom of the system has a lower density than that of the fluid above it. In the absence of a headspace, mixing in the expanded bed can be modeled as a single, well-mixed vessel, with first-order dynamics. In the presence of a headspace, the system exhibits second-order dynamics for the densities typically encountered in protein chromatography, and can be modeled as two well-mixed vessels (the expanded bed and the headspace) arranged in series. In this paper, the mixing dynamics of the expanded bed are described and a mathematical model of the system is presented. Experimental measurements of density changes during the dilution of sucrose and salt solutions in a STREAMLINE 25 column are presented. These show excellent agreement with predictions using the model. A number of strategies for wash and elution in expanded mode, both in the presence and absence of headspace, are discussed.
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References
Amersham Pharmacia Biotech. Expanded Bed Adsorption: Principles and Methods. Supplier Handbook.
Anspach FB and Curbelo D et al. (1999) 'Expanded bed chromatography in primary protein purification.' J. Chromatogr. A 865: 129–144.
Baines WD and Turner JS (1969). 'Turbulent buoyant convection from a source in a confined region.' J. Fluid Mechanics 37(1): 51–80.
Benneker AH, Kronberg AE et al. (1998) 'Influence of buoyant forces on the flow of gases through packed beds at elevated pressures.' American Institute of Chemical Engineers J. 44(2): 263–270.
Bequette BW (1998) Process dynamics, modelling, analysis and simulation. NJ, Prentice-Hall PTR.
Chase HA (1994) 'Purification of proteins by adsorption chromatography in expanded beds.' Trends Biotechnology 12: 296–303.
Cheremisinoff NP (1986) 'Review of experimental methods for studying the hydrodynamics of gas-fluidized beds.' Industrial and Engineering Chemistry Process Design and Development 25(2): 329–351.
Chiang H-W and Jones SCA (1993) 'Simulating the mixing of helium and air by mixing salt water and fresh water in a scaled enclosure.' Nuclear Engineering and Design 143: 55–67.
Coughanowr DR (1991) Process systems analysis and control. McGraw-Hill, Hightstown, NJ.
Davies GS (1986) 'Mixing and segregation of particulate solids-review of recent advancements and developments.' Particle Sci. Technol. 4(3): 277–303.
Gunn DJ (1968) 'Mixing in packed and fluidized beds.' Chem. Eng. 219: CE153-CE172.
Hjorth R (1999) 'Expanded bed adsorption: elution in expanded bed mode.' Bioseparation 8: 1–9.
Hjorth R and Kampe S et al. (1995) 'Analysis of some operating parameters of novel adsorbents for recovery of proteins in expanded beds.' Bioseparation 5: 217–223.
Isco I (1985) ISCOTABLES A handbook of data for biological and physical scientist. Isco, Inc, Lincoln, Nebraska. Kunii D and Levenspiel O (1991) Fluidization Engineering. Butterworth-Heinemann, Stoneham, MA.
Lan JC-W and Hamilton GE et al. (1999) 'Physical and biochemical characterization of a simple intermediate between fluidized and expanded bed contactors.' Bioseparation 8(1/5): 43–51.
Lihme A and Zafirakos E et al. (1999) 'Simplified and more robust EBA processes by elution in expanded bed mode.' Bioseparation 8: 93–97.
Mooson K (1992) 'Particulate fluidization: an overview.' Adv. Chem. Eng. 17: 207–360.
Oldshue JY (1969) 'Mixing.' Indust. Eng. Chem. 61(11): 121–127.
Ross SL (1980) Introduction to ordinary differential equations. John Wiley & Sons, New York.
Singh PC and Pandey GN, et al. (1973) 'Residence time distribution in fluidized beds.' Indian Chem. Eng. 15(1): 24–30.
Thommes J (1997) 'Fluidised bed adsorption as a primary recovery step in protein purification.' Adv. Biochem. Eng. 58: 185–230.
Thommes J and Bader A, et al. (1996) 'Isolation of monoclonal antibodies from cell containing hybridoma broth using a protein A coated adsorbent in expanded beds.' J. Chromatogr. 752: 111–122.
Zlokarnik M (1998) 'Problems in the application of dimensional analysis and scale-up of mixing operations.' Chem. Eng. Sci. 53(17): 3023–3030.
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Fee, C.J., Liten, A.D. Buoyancy-induced mixing during wash and elution steps in expanded bed adsorption. Bioseparation 10, 21–30 (2001). https://doi.org/10.1023/A:1012044024909
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DOI: https://doi.org/10.1023/A:1012044024909