Abstract
In this work, the diffusion properties of single component n-heptane and toluene as well as their binary mixtures in two SBA-15 samples with different structural characteristics were studied by the standard Zero Length Column (ZLC) technique under three different concentration levels. A theoretical ZLC desorption model considering the Generalized Maxwell-Stefan (GMS) formulation was developed. Using the independently measured single component equilibrium and kinetic parameters, the model was able to reasonably predict experimental binary ZLC desorption curve for countercurrent diffusion of toluene in the presence of n-heptane. However, there was a significant deviation between model prediction results and experimental data for countercurrent desorption of n-heptane in the presence of toluene. The diffusion of n-heptane is reduced by the presence of toluene, regardless of the relative content of micropores in the intrawall pores, while that of toluene is virtually unaffected by the counter-diffusion of n-heptane. The observed phenomena cannot be addressed by the simple model considering the cross term diffusion effect. The structural property of material and the molecular characteristics of probe molecules were used to account for the difference in the behavior between n-heptane and toluene.
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Baertsch, C.D., Funke, H.H., Falconer, J.L., Noble, R.D.: Permeation of aromatic hydrocarbon vapors through silicalite-zeolite membranes. J. Phys. Chem. 100, 7676–7679 (1996)
Brandani, S., Jama, M., Ruthven, D.M.: Diffusion, self-diffusion and counter-diffusion of benzene and p-xylene in silicalite. Micropor. Mesopor. Mater. 35–36, 283–300 (2000a)
Brandani, S., Jama, M., Ruthven, D.M.: Counterdiffusion of p-xylene/benzene and p-xylene/o-xylene in silicalite studied by the zero-length column technique. Ind. Eng. Chem. Res. 39, 821–828 (2000b)
Brandani, S., Jama, M., Ruthven, D.M.: ZLC measurements under non-linear conditions. Chem. Eng. Sci. 55, 1205–1212 (2000c)
Choi, M., Heo, W., Kleitz, F., Ryoo, R.: Facile synthesis of high quality mesoporous SBA-15 with enhanced control of the porous network connectivity and wall thickness. Chem. Commun. 12, 1340–1341 (2003)
Dvoyashkin, M., Khokhlov, A., Naumov, S., Valiullin, R.: Pulsed field gradient NMR study of surface diffusion in mesoporous adsorbents. Micropor. Mesopor. Mater. 125, 58–62 (2009)
Eić, M., Ruthven, D.M.: A new experimental-technique for measurement of intracrystalline diffusivity. Zeolites 8, 40–45 (1988)
Galarneau, A., Cambon, H., Di Renzo, F., Ryoo, R., Choi, M., Fajula, F.: Microporosity and connections between pores in SBA-15 mesostructured silicas as a function of the temperature of synthesis. New J. Chem. 27, 73–79 (2003)
Iliyas, A., Eić, M., Zahedi-Niaki, M.H., Vasenkov, S.: Toward observation of single-file diffusion using the tracer zero-length column method. J. Phys. Chem. B 112, 3821–3825 (2008)
Kärger, J., Ruthven, D.M.: Diffusion in Zeolites and Other Microporous Materials. Wiley, New York (1992)
Krishna, R.: A unified approach to the modeling intraparticle diffusion in adsorption processes. Gas Sep. Purif. 7, 91–104 (1993)
Kruk, M., Jaroniec, M., Ko, C.H., Ryoo, R.: Characterization of the porous structure of SBA-15. Chem. Mater. 12, 1961–1968 (2000)
Kruk, M., Jaroniec, M., Sayari, A.: Application of large pore MCM-41 molecular sieves to improve pore size analysis using nitrogen adsorption measurements. Langmuir 13, 6267–6273 (1997)
Newalkar, B.L., Choudary, N.V., Kumar, P., Komarneni, S., Bhat, T.S.G.: Exploring the potential of mesoporous silica, SBA-15, as an adsorbent for light hydrocarbon separation. Chem. Mater. 14, 304–309 (2002)
Qureshi, W.R., Wei, J.: One- and two-component diffusion in zeolite ZSM-5 I. theoretical. J. Catal. 126, 126–146 (1990a)
Qureshi, W.R., Wei, J.: One- and two-component diffusion in zeolite ZSM-5 II. experimental. J. Catal. 126, 147–172 (1990b)
Ravikovitch, P.I., Neimark, A.V.: Characterization of micro- and mesoporosity in SBA-15 materials from adsorption data by the NLDFT method. J. Phys. Chem. B 105, 6817–6823 (2001)
Rioux, R.M., Song, H., Hoefelmeyer, J.D., Yang, P., Somorjai, G.A.: High-surface-area catalyst design: synthesis, characterization, and reaction studies of platinum nanoparticles in mesoporous SBA-15 silica. J. Phys. Chem. B 109, 2192–2202 (2005)
Round, G.F., Habgood, H.W., Newton, R.: Diffusion in a binary adsorbed phase. Sep. Sci. 1, 219–227 (1966)
Sun, Y., Han, Y., Yuan, L., Ma, S., Jiang, D., Xiao, F.S.: Microporosity in ordered mesoporous aluminosilicates characterized by catalytic probing reactions. J. Phys. Chem. B 107, 1853–1857 (2003)
Valiullin, R., Kortunov, P., Kärger, J., Timoshenko, V.: Surface self-diffusion of organic molecules adsorbed in porous silicon. J. Phys. Chem. B 109, 5746–5752 (2005)
Vignes, A.: Diffusion in binary solutions. Ind. Eng. Chem. Fundamental 5, 189–199 (1966)
Vinh-Thang, H., Huang, Q.L., Eić, M., Trong-On, D., Kaliaguine, S.: Adsorption of C7 hydrocarbons on biporous SBA-15 mesoporous silica. Langmuir 21, 5094–5101 (2005a)
Vinh-Thang, H., Huang, Q.L., Eić, M., Trong-On, D., Kaliaguine, S.: Structure and diffusion characterization of SBA-15 materials. Langmuir 21, 2051–2057 (2005b)
Vinh-Thang, H., Huang, Q.L., Eić, M., Trong-On, D., Kaliaguine, S.: Effect of the intrawall microporosity on the diffusion characterization of bi-porous SBA-15 materials. In: Conner, C., Fraissard, J. (eds.) Fluid Transport in Nanoporous Material. NATO Sci. Series, vol. 219, pp. 591–602. Springer, Berlin (2006a)
Vinh-Thang, H., Huang, Q.L., Ungureanu, A., Eić, M., Trong-On, D., Kaliaguine, S.: Structural and diffusion characterizations of steam-stable mesostructured zeolitic UL-ZSM-5 materials. Langmuir 22, 4777–4786 (2006b)
Zhao, D.Y., Huo, Q., Feng, J., Chmelka, B.F., Stucky, G.D.: Nonionic triblock and star diblock copolymer and oligomeric surfactant syntheses of highly ordered, hydrothermally stable, mesoporous silica structures. J. Am. Chem. Soc. 120, 6024–6036 (1998)
Zhao, J.W., Gao, F., Fu, Y., Wan, J., Yang, P., Zhao, D.Y.: Biomolecule separation using large pore mesoporous SBA-15 as a substrate in high performance liquid chromatography. Chem. Commun. 752–753 (2002)
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Huang, Q., Qamar, R.A. & Eić, M. Single component and binary diffusion of n-heptane and toluene in SBA-15 materials. Adsorption 17, 27–38 (2011). https://doi.org/10.1007/s10450-010-9268-4
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DOI: https://doi.org/10.1007/s10450-010-9268-4