Abstract
A detailed model for nonisothermal sorption of multicomponent mixtures in a single sorbent particle (monodisperse or bidisperse with negligible intracrystalline mass transport limitations) under pressure swing conditions is developed in this study. The dusty-gas model is used to describe the coupling of the molar fluxes, the temperature, the partial pressures and the partial pressure gradients of the components in the pore space of the particle. The variations of the temperature are described by an energy equation in which both convective and conductive modes of heat transport are accounted for. No limitations are imposed on the number of the components in the mixture and on the type of the adsorption isotherm. The model is applied in the investigation of the industrially important air-zeolite 5A system. Two cases with respect to the surrounding gas phase are examined: infinite environment, which is representative for single particle experiments, and finite environment, which is representative for the situation in packed bed adsorbers. It is found that in an infinite environment the external and internal temperature gradients are equally important while in a finite environment the external heat transport limitations are negligible. It is concluded that in modeling the nonisothermal operation of adsorption processes occurring in packed beds it is not necessary to allow for the temperature differences between the gas phase and the surface of the adsorbing particles. Furthermore, if the temperature gradients within the particles can be neglected, only a single temperature equation is needed to describe the energy transport in the bed.
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References
Alpay, E., C.N. Kenney, and D.M. Scott, "Simulation of a Rapid Pressure Swing Adsorption and Reaction Processes," Chem. Engng. Sci., 48, 3173-3186 (1993).
Brunovska, A., V. Hlavacek, J. Ilavsky, and J. Valtyni, "An Analysis of a Nonisothermal One-Component Sorption in a Single Adsorbent Particle," Chem. Engng. Sci., 33, 1385-1391 (1978).
Chihara, K., M. Suzuki, and K. Kawazoe, "Effect of Heat Generation on Measurement of Adsorption Rate by Gravimetric Method," Chem. Engng. Sci., 31, 505-507 (1976).
De Boor, C.A., A Practical Guide to Splines, Springer-Verlag, New York, 1978.
Dunne, J.A., R. Mariwala, M. Rao, S. Sircar, R.J. Gorte, and A.L. Myers, "Calorimetric Heats of Adsorption and Adsorption Isotherms. 1. O2, N2, Ar, CO2, CH9, C9H9, and SF6 on NaX, H-ZSM-5, and Na-ZSM-5 Zeolites," Langmuir, 12, 5896-5904 (1996).
Farooq, S., M.N. Rathor, and K. Hidajat, "A Predictive Model for a Kinetically Controlled Pressure Swing Adsorption Separation Process," Chem. Engng. Sci., 48, 4129-4141 (1993).
Gear, C.W., Numerical Initial Value Problems in Ordinary Differential Equations, Prentice Hall, Englewood Cliffs, NJ, 1971.
Haq, N. and D.M. Ruthven, "A Chromatographic Study of Sorption and Diffusion in 5A Zeolite," J. Colloid Interface Sci., 112, 164- 169 (1986).
Haul, R. and H. Stremming, "Nonisothermal Sorption Kinetics in Porous Adsorbents," J. Colloid Interface Sci., 97, 348-355 (1984).
Hu, X. and D.D. Do, "Validity of Isothermality in Adsorption Kinetics of Gases in Bidispersed Solids," A.I.Ch.E. J., 41, 1581- 1584 (1995).
Ilavsky, J., A. Brunovska, and V. Hlavacek, "Experimental Observation of Temperature Gradients Occurring in a Single Zeolite Pellet," Chem. Engng. Sci., 35, 2475-2479 (1980).
Jackson, R., Transport in Porous Catalysts, Elsevier, New York, 1977.
Kondis, E.F. and J.S. Dranoff, "Nonisothermal Sorption of Ethane by 4A Molecular Sieves," AIChE Symp. Ser., 67(117), 25-34 (1971).
Lee, K.-L. and D.M. Ruthven, "Analysis of Thermal Effects in Adsorption Rate Measurements," J. Chem. Soc. Faraday I, 75, 2407-2422 (1979).
Lopes, J.C., M.M. Dias, V.G. Mata, and A.E. Rodrigues, "Flow Field and Non-Isothermal Effects on Diffusion, Convection, and Reaction in Permeable Catalysts," Ind. Engng. Chem. Res., 34, 148-157 (1995).
Mason, E.A. and A.P. Malinauskas, Gas Transport in Porous Media: The Dusty-Gas Model, Elsevier, New York, 1983.
Miller, G.W., K.S. Knaebel, and K.G. Ikels, "Equilibria of Nitrogen, Oxygen, Argon, and Air in Molecular Sieve 5A," A.I.Ch.E. J., 33, 194-201 (1987).
Ofori, J.Y. and S.V. Sotirchos, "Dynamic Convection-Driven Thermal Gradient Chemical Vapor Infiltration," J. Mater. Res., 11, 2541-2555 (1996).
Ruthven, D.M., L.-K. Lee, and H. Yucel, "Kinetics of Non-Isothermal Sorption in Molecular Sieve Crystals," A.I.Ch.E. J., 26, 16-23 (1980).
Ruthven, D.M. and Z. Xu, "Diffusion of Oxygen and Nitrogen in 5A Zeolite Crystals and Commercial 5A Pellets," Chem. Engng. Sci., 48, 3307-3312 (1993).
Serbezov, A., Ph.D. Dissertation, University of Rochester, Rochester, NY, 1997.
Serbezov, A.S. and S.V. Sotirchos, "Multicomponent Pressure Swing Adsorption: Semianalytical Solution for Local Equilibrium and Comparison with the Predictions of a Generalized Multicomponent Model," A.I.Ch.E. Meeting, San Francisco, 1994.
Serbezov, A. and S.V. Sotirchos, "Multicomponent Transport Effects in Sorbent Particles under Pressure Swing Conditions," Ind. Engng. Chem. Res., 36, 3002-3012 (1997b).
Serbezov, A. and S.V. Sotirchos, "Generalized Linear Driving Force Approximation for Modeling Multicomponent Adsorption-Based Separations," Submitted for publication (1997b).
Sorial, G.A., W.H. Granville, and W.O. Daly, "Adsorption Equilibria for Oxygen and Nitrogen Gas Mixtures on 5A Molecular Sieves," Chem. Engng. Sci., 38, 1517-1523 (1983).
Sotirchos, S.V., "Multicomponent Diffusion and Convection in Capillary Structures," A.I.Ch.E. J., 35, 1953-1961 (1989).
Sotirchos, S.V., "Dynamic Modeling of Chemical Vapor Infiltration," A.I.Ch.E. J., 38, 1365-1378 (1991).
Sotirchos, S.V. and N.R. Amundson, "Dynamic Behavior of a Porous Char Particle Burning in an Oxygen-Containing Environment," A.I.Ch.E. J., 30, 537-548 (1984a).
Sotirchos, S.V. and N.R. Amundson, "Part II: Transient Analysis of a Shrinking Particle," A.I.Ch.E. J., 30, 549-556 (1984a).
Sun, L.M. and F.A. Meunier, "Detailed Model for Nonisothermal Sorption in Porous Adsorbents," Chem. Engng. Sci., 42, 1585- 1593 (1987).
Tomadakis, M.M. and S.V. Sotirchos, "Ordinary, Transition, and Knudsen Regime Diffusion in Random Capillary Structures," Chem. Engng. Sci., 48, 3323-3333 (1993).
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Serbezov, A., Sotirchos, S.V. Mathematical Modeling of Multicomponent Nonisothermal Adsorption in Sorbent Particles Under Pressure Swing Conditions. Adsorption 4, 93–111 (1998). https://doi.org/10.1023/A:1008819001197
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DOI: https://doi.org/10.1023/A:1008819001197