Abstract
The quantification of the permeation of the Fischer-Tropsch reaction mixture through a silicalite-1 zeolite membrane in which is integrated in to fixed bed reactor was theoretically investigated. The approach is based on the prediction of the permeation parameters by using two different mechanisms including surface diffusion and gaseous diffusion. It was found that under our investigated conditions, the total permeation could be governed by surface diffusion model since the contribution of this mechanism is dominant versus the gaseous diffusion. Noteworthy, our results show that except for the selective gas permeation of carbon dioxide, the measuring factors of different permeates were proportional to the operating pressure. Hydrocarbons with low molecular weight diffuse greater than long-chain hydrocarbons. Furthermore, the high adsorbed molecules are more likely to be affected by the high processing temperature. It can be also highlighted that the permeate amounts has no important effect on the product distribution which is characterized by the olefins to paraffins ratios. So the assumption that considers the separation of CO 2 without assuming other components permeation is well supported.
Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
Appendix: Reaction scheme and kinetic model for Fe-Cu-K catalyst ( Bellal and Chibane 2020)
For a chain length of n = 1:
For a chain length of n = 2:
The kinetic rate of WGS reaction is given by the following equation:
Nomenclature
- A
Cross-section (m 2)
- B
Perimeter of cross-section (m)
- Cpg
Specific heat transfer of gaseous mixture at constant pressure (J mol -1 K -1)
- dp
Diameter of catalyst particle (m)
- Dc
Diameter of cooling tube (m)
Diffusivity of component i (m 2 s -1)
Diffusivity of component i at zero loadings and infinite temperature (m 2 s -1)
Diffusivity of component i at zero loadings (m 2 s -1)
- E5
Activation energy for paraffin formation (J mol -1)
Activation energy for olefin formation (J mol -1)
- E5,M
Activation energy for methane formation (J mol -1)
- E5
Activation energy for paraffin formation (J mol -1)
Activation energy for olefin formation (J mol -1)
- Ev
Activation energy for WGS reaction (J mol -1)
- Edif, i
Diffusivity activation energy of component i ( kJ mol -1)
Reaction flux of components i (mol s -1)
Permeate flux of components i (mol s -1)
Residual flux of components i (mol s -1)
- FT
Total molar flow rate in the reaction side (mol s -1)
- k1
Rate constant of CO adsorption (mol kg -1 s -1 bar -1)
- k5
Rate constant of paraffin formation (mol kg -1 s -1 bar -1)
- k5,0
Pre-exponenetial factor of rate constant of paraffin formation (mol kg -1 s -1 bar -1)
- k5 M
Rate constant of methane formation (mol kg -1 s -1 bar -1)
- k5 M,0
Pre-exponential factor of rate constant of methane formation (mol kg -1 s -1 bar -1)
- k6
Rate constant of olefin desorption reaction (mol kg -1 s -1)
- k6,0
Pre-exponential factor of rate constant of olefin desorption reaction (mol kg -1 s -1)
- k-6
Rate constant of olefin re-adsorption reaction (mol kg -1 s -1 bar -1)
- kv
Rate constant of CO 2 formation (mol kg -1 s -1 bar -1.5)
- kv,0
Pre-exponential factor of rate constant of CO 2 formation (mol kg -1 s -1 bar -1.5)
- K2
Equilibrium constant of CH intermediate formation
- K3
Equilibrium constant of CH 2 intermediate formation
- K4
Equilibrium constant of CH 3 alkyl formation
- Kv
Group of constants in WGS reaction
- Ki
Adsorption equilibrium constant of component i (bar -1)
- Ki,0
Adsorption equilibrium constant of component i at infinite temperature (bar -1)
- KWGS
Equilibrium constant of WGS reaction
- L
Reactor length (m)
- l
Dimensionless reactor length
- O/ P
Olefin over paraffin selectivity ratio
- Pi
Partial pressure of components i (bar)
- Pperm
Partial pressure in permeate side (bar)
- Preac
Partial pressure in reaction side (bar)
- qi
Amount adsorbed of component i (mol kg -1)
Saturation amount adsorbed of component i (mol kg -1)
- R
Universal gas constant (8.314 J mol -1K -1)
- Rj
Rate of reaction j (mol kg -1 s -1)
Paraffin reaction rate (mol kg -1 s -1)
Olefin reaction rate (mol kg -1 s -1)
- RWGS
Water-gas shift reaction rate (mol kg -1 s -1)
- T
Temperature (K)
- Tsh
Shell temperature (K)
- Tref
Reference temperature (K)
- Ush
Heat transfer coefficient shell-gases (W m -2 K -1)
- v
Gas linear velocity (m s -1)
- x
Membrane coordinate
- z
Probability of diffusion in the right direction
- Greek letters
- ?
Porosity of catalytic bed
- ?m
Porosity of membrane-support layer
- ?
Catalyst density (kg m -3)
- ?m
Membrane density (kg m -3)
- vij
Stoichiometric coefficient of components i in reaction j
- 5
Gas dynamic viscosity (bar s -1)
- d
Membrane thickness (m)
- ?
Diffusional length (m)
- ?i
Fractional sites occupancy for component i
- ? Hads, i
Adsorption enthalpy of component i ( kJ mol -1)
- ? Sads, i
Adsorption entropy of component i ( kJ mol -1)
Enthalpy of reaction j (J mol -1)
- Subscripts
- i
Index indicating components
- j
Index indicating reactions
- m
Membrane
- n
Chain length of hydrocarbons
- Abbreviations
- GD
Gaseous diffusion
- HC
Hydrocarbons
- PF
Permeation factor
- SD
Surface diffusion
- SP
Selective permeation
References
Algieri, C., P. Bernardo, G. Golemme, G. Barbieri, and E. Drioli. 2003. "Permeation Properties of a Thin Silicalite-1 (MFI) Membrane." Journal of Membrane Science 222 (1-2): 181-90, https://doi.org/10.1016/s0376-7388(03)00286-2. Search in Google Scholar
Arik, I. C., J. F. Denayer, and G. V. Baron. 2003. "High-Temperature Adsorption of n-Alkanes on ZSM-5 Zeolites: Influence of the Si/Al Ratio and the Synthesis Method on the Low-Coverage Adsorption Properties." Microporous and Mesoporous Materials 60 (1-3): 111-24, https://doi.org/10.1016/s1387-1811(03)00332-9. Search in Google Scholar
Bakker, W. J. W., F. Kapteijn, J. Poppe, and J. A. Moulijn. 1996. "Permeation Characteristics of a Metal-Supported Silicalite-1 Zeolite Membrane." Journal of Membrane Science 117 (1-2): 57-78, https://doi.org/10.1016/0376-7388(96)00035-x. Search in Google Scholar
Bakker, W. J. W., L. J. P. Van Den Broeke, F. Kapteijn, and J. A. Moulijn. 1997. "Temperature Dependence of One-Component Permeation Through a Silicalite-1 Membrane." AIChE Journal 43 (9): 2203-14, https://doi.org/10.1002/aic.690430907. Search in Google Scholar
Bellal, A., and L. Chibane. 2020. "A New Concept for Control and Orientation of the Distribution of Clean Hydrocarbons Produced by Fischer-Tropsch Synthesis over an Industrial Iron Catalyst." Reaction Kinetics, Mechanisms and Catalysis 129 (2): 725-42, https://doi.org/10.1007/s11144-020-01726-7. Search in Google Scholar
Bldker, C., C. Pasel, M. Luckas, F. Dreisbach, and D. Bathen. 2017. "Investigation of Load-Dependent Heat of Adsorption of Alkanes and Alkenes on Zeolites and Activated Carbon." Microporous and Mesoporous Materials 241: 1-10, https://doi.org/10.1016/j.micromeso.2016.12.037. Search in Google Scholar
Dong, J., Y. S. Lin, and W. Liu. 2000. "Multicomponent Hydrogen/hydrocarbon Separation by MFI-Type Zeolite Membranes." AIChE Journal 46 (10): 1957-66, https://doi.org/10.1002/aic.690461008. Search in Google Scholar
Dvoyashkina, N., D. Freude, A. G. Stepanov, W. Bvhlmann, R. Krishna, J. Kdrger, and J. Haase. 2018. "Alkane/alkene Mixture Diffusion in Silicalite-1 Studied by MAS PFG NMR." Microporous and Mesoporous Materials 257: 128-34, https://doi.org/10.1016/j.micromeso.2017.08.015. Search in Google Scholar
Farzaneh, A., M. Zhou, E. Potapova, Z. Bacsik, L. Ohlin, A. Holmgren, J. Hedlund, and M. Grahn. 2015. "Adsorption of Water and Butanol in Silicalite-1 Film Studied with In Situ Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy." Langmuir 31 (17): 4887-94, https://doi.org/10.1021/acs.langmuir.5b00489. Search in Google Scholar PubMed
Gardner, T. Q., J. L. Falconer, and R. D. Noble. 2004. "Transient Permeation of Butanes Through ZSM-5 and ZSM-11 Zeolite Membranes." AIChE Journal 50 (11): 2816-34, https://doi.org/10.1002/aic.10217. Search in Google Scholar
Jakobtorweihen, S., N. Hansen, and F. J. Keil. 2005. "Molecular Simulation of Alkene Adsorption in Zeolites." Molecular Physics 103 (4): 471-89, https://doi.org/10.1080/00268970512331316021. Search in Google Scholar
Jousse, F., L. Leherte, and D. P. Vercauteren. 1997. "Energetics and Diffusion of Butene Isomers in Channel Zeolites from Molecular Dynamics Simulations." Journal of Molecular Catalysis A: Chemical 119 (1-3): 165-76, https://doi.org/10.1016/s1381-1169(96)00480-3. Search in Google Scholar
Kapteijn, F., W. J. W. Bakker, G. Zheng, J. Poppe, and J. A. Moulijn. 1995. "Permeation and Separation of Light Hydrocarbons Through a Silicalite-1 Membrane." The Chemical Engineering Journal and the Biochemical Engineering Journal 57 (2): 145-53, https://doi.org/10.1016/0923-0467(94)02941-5. Search in Google Scholar
Koriabkina, A. O. 2003. Diffusion of Alkanes in MFI-type Zeolites. PhD Thesis. Eindhoven, The Nether-lands: Technische Universiteit Eindhoven. Search in Google Scholar
Leppdjdrvi, T., I. Malinen, D. Korelskiy, J. Hedlund, and J. Tanskanen. 2014. "Maxwell-Stefan Modeling of Ethanol and Water Unary Pervaporation Through a High-Silica MFI Zeolite Membrane." Industrial & Engineering Chemistry Research 53 (1): 323-32, https://doi.org/10.1021/ie400814z. Search in Google Scholar
Nagumo, R., H. Takaba, and S.-I. Nakao. 2003. "Prediction of Ideal Permeability of Hydrocarbons Through an MFI-type Zeolite Membrane by a Combined Method Using Molecular Simulation Techniques and Permeation Theory." The Journal of Physical Chemistry B 107 (51): 14422-8, https://doi.org/10.1021/jp034401n. Search in Google Scholar
Rohde, M. P. 2011. In-Situ H2O Removal via Hydrophilic Membranes During Fischer-Tropsch and Other Fuel-Related Synthesis Reactions. Karlsruhe: KIT Scientific Publishing. Search in Google Scholar
Sandstrvm, L., E. Sjvberg, and J. Hedlund. 2011. "Very High Flux Mfi Membrane for CO2 Separation." Journal of Membrane Science 380 (1-2): 232-40, https://doi.org/10.1016/j.memsci.2011.07.011. Search in Google Scholar
Talu, O., M. S. Sun, and D. B. Shah. 1998. "Diffusivities of n-Alkanes in Silicalite by Steady-State Single-Crystal Membrane Technique." AIChE Journal 44 (3): 681-94, https://doi.org/10.1002/aic.690440316. Search in Google Scholar
van den Bergh, J., W. Zhu, J. C. Groen, F. Kapteijn, J. A. Moulijn, K. Yajima, K. Nakayama, T. Tomita, and S. Yoshida. 2007. "Natural Gas Purification with a DDR Zeolite Membrane; Permeation Modelling with Maxwell-Stefan Equations." Studies in Surface Science and Catalysis 170: 1021-7, https://doi.org/10.1016/s0167-2991(07)80955-4. Search in Google Scholar
Wang, C., B. Li, Y. Wang, and Z. Xie. 2013. "Insight into the Topology Effect on the Diffusion of Ethene and Propene in Zeolites: A Molecular Dynamics Simulation Study." Journal of Energy Chemistry 22 (6): 914-8, https://doi.org/10.1016/s2095-4956(14)60272-2. Search in Google Scholar
Xiao, J., and J. Wei. 1992. "Diffusion Mechanism of Hydrocarbons in Zeolites-I. Theory." Chemical Engineering Science 47 (5): 1123-41, https://doi.org/10.1016/0009-2509(92)80236-6. Search in Google Scholar
Yu, L., S. Fouladvand, M. Grahn, and J. Hedlund. 2019. "Ultra-thin MFI Membranes with Different Si/Al Ratios for CO2/CH4 Separation." Microporous and Mesoporous Materials 284: 258-64, https://doi.org/10.1016/j.micromeso.2019.04.042. Search in Google Scholar
Zhu, W., P. Hrabanek, L. Gora, F. Kapteijn, and J. A. Moulijn. 2006. "Role of Adsorption in the Permeation of CH4 and CO2 through a Silicalite-1 Membrane." Industrial & Engineering Chemistry Research 45 (2): 767-76, https://doi.org/10.1021/ie0507427. Search in Google Scholar
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