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Publications (10 of 29) Show all publications
Korelskiy, D., Ye, P., Nabavi, M. S. & Hedlund, J. (2017). Selective blocking of grain boundary defects in high-flux zeolite membranes by cokin. Journal of Materials Chemistry A, 5(16), 7295-7299
Open this publication in new window or tab >>Selective blocking of grain boundary defects in high-flux zeolite membranes by cokin
2017 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, no 16, p. 7295-7299Article in journal (Refereed) Published
Abstract [en]

Commercial application of zeolite membranes has been hindered by the challenge of preparing defect-free membranes. Herein, we report a facile method able to selectively plug grain boundary defects in high-flux MFI zeolite membranes by coking of iso-propanol at 350 °C. After modification, the permeance via defects was reduced by 70%, whereas that via zeolite pores was reduced by only 10%.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-62738 (URN)10.1039/C7TA01268C (DOI)000399390300006 ()2-s2.0-85017599078 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-04-25 (andbra)

Available from: 2017-03-28 Created: 2017-03-28 Last updated: 2019-11-26Bibliographically approved
Korelskiy, D., Grahn, M., Ye, P., Zhou, M. & Hedlund, J. (2016). A study of CO2/CO separation by sub-micron b-oriented MFI membranes (ed.). Paper presented at . RSC Advances, 6(70), 65475-65482
Open this publication in new window or tab >>A study of CO2/CO separation by sub-micron b-oriented MFI membranes
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2016 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 70, p. 65475-65482Article in journal (Refereed) Published
Abstract [en]

Separation of CO2 and CO is of great importance for many industrial applications. Today, CO2 is removed from CO mainly by adsorption or physical or chemical absorption systems that are energy-intensive and expensive. Membranes are listed among the most promising sustainable and energy-efficient alternatives for CO2 separation. Here, we study CO2/CO separation by novel sub-micron b-oriented MFI zeolite membranes in a temperature range of 258-303 K and at a feed pressure of 9 bar. Under all experimental conditions studied, the membranes were CO2-selective and displayed high CO2 permeance ranging from 17 000 to 23 000 gpu. With decreasing temperature, the CO2/CO selectivity was increasing, reaching a maximum of 26 at 258 K. We also developed a mathematical model to describe the membrane process, and it indicated that the membrane separation performance was a result of selective adsorption of CO2 on the polar zeolite. The heat of adsorption of CO2 on the zeolite is more negative due to the high quadrupole moment and polarisability of the molecule as compared to CO. At the same time, diffusional coupling (correlation effects) at high adsorbed loadings was found to favour the overall CO2/CO selectivity of the membranes by reducing the diffusivity of the lighter CO molecule in the ca. 0.55 nm pores in the zeolite. The model also indicated that the separation performance was limited by the mass transfer resistance in the support and concentration polarisation on the feed side of the membrane.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-7211 (URN)10.1039/C6RA14544B (DOI)000379577800024 ()2-s2.0-84978766579 (Scopus ID)58af75f0-175a-4e0c-ba22-8052ab996b55 (Local ID)58af75f0-175a-4e0c-ba22-8052ab996b55 (Archive number)58af75f0-175a-4e0c-ba22-8052ab996b55 (OAI)
Note
Validerad; 2016; Nivå 2; 20160705 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Ye, P., Grahn, M., Korelskiy, D. & Hedlund, J. (2016). Efficient Separation of N2 and He at Low Temperature Using MFI Membranes (ed.). AIChE Journal, 62(8), 2833-2842
Open this publication in new window or tab >>Efficient Separation of N2 and He at Low Temperature Using MFI Membranes
2016 (English)In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 62, no 8, p. 2833-2842Article in journal (Refereed) Published
Abstract [en]

Ultra-thin MFI membranes were evaluated for N2/He separation over the temperature range of 85–260 K for the first time. The membranes were rather nitrogen selective at all the conditions investigated. A highest N2/He selectivity of 75.7 with a high N2 flux of 83 kg/m2/h was observed at 124 K. The separation was attributed to adsorption selectivity to N2, effectively hindering the transport of He in the zeolite pores. The exceedingly high permeance even at low temperatures was ascribed to the ultrathin (<1μm) membrane used. As the pressure ratios increased, a better separation performance was obtained. A mathematical model showed the largest difference of adsorbed loading over the film at ca. 120 K was the main reason for the observed maximum selectivity. Further, the modelling indicated the selectivity would increase 2–3 times by reducing the influence of defects, concentration polarization, and pressure drop over the support.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-14246 (URN)10.1002/aic.15258 (DOI)000382986000022 ()2-s2.0-84963838612 (Scopus ID)d9915577-3ec2-44db-b44a-2716f7d3a5c3 (Local ID)d9915577-3ec2-44db-b44a-2716f7d3a5c3 (Archive number)d9915577-3ec2-44db-b44a-2716f7d3a5c3 (OAI)
Note

Validerad; 2016; Nivå 2; 20160330 (dankor)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Karimi, S., Korelskiy, D., Mortazavi, Y., Khodadadi, A. A., Sardari, K., Esmaeili, M., . . . Hedlund, J. (2016). High flux acetate functionalized silica membranes based on in-situ co-condensation for CO2/N2 separation (ed.). Journal of Membrane Science, 520, 574-582
Open this publication in new window or tab >>High flux acetate functionalized silica membranes based on in-situ co-condensation for CO2/N2 separation
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2016 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 520, p. 574-582Article in journal (Refereed) Published
Abstract [en]

Acetate-functionalized silica membranes were prepared via co-condensation. The molar ratio of functional groups in the silica matrix was varied in the range of 0–0.6, denoted by x. The presence of functional groups bonded to the silica network was revealed by FTIR and 29Si and 13C solid-state NMR analysis. The stability of the groups was studied by TG analysis. The membranes were evaluated for CO2/N2 mixture separation in a temperature range of 253–373 K using a feed pressure of 9 bar and a sweep gas kept at atmospheric pressure on the permeate side. The membranes were found to be CO2-selective at all the conditions studied. The highest observed selectivity was 16 for x=0.4, with a CO2 permeance of 5.12×10−7 mol s−1 m−2 Pa−1. For x=0.2, a permeance of as high as 20.74×10−7 mol s−1 m−2 Pa−1 with a CO2/N2 selectivity of 7.5 was obtained. This permeance is the highest reported for CO2/N2 separation using functionalized silica membranes. It is proposed that the separation mechanism between CO2 and N2 was the preferential adsorption of CO2, which inhibited adsorption and permeation of N2 through the silica pore network. Permporometry results revealed that as the loading of functional groups increased, the He permeance decreased. It was also indicated that the quantity of micropores in the functionalized membrane was higher than that in the parent silica membrane.

National Category
Chemical Process Engineering Physical Chemistry
Research subject
Chemical Technology; Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-2404 (URN)10.1016/j.memsci.2016.08.017 (DOI)000384785000056 ()2-s2.0-84989360849 (Scopus ID)005ea5bf-a4fa-488f-a4a5-8b651389893c (Local ID)005ea5bf-a4fa-488f-a4a5-8b651389893c (Archive number)005ea5bf-a4fa-488f-a4a5-8b651389893c (OAI)
Note

Validerad; 2016; Nivå 2; 20160815 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Karimi, S., Korelskiy, D., Yu, L., Mouzon, J., Khodadadi, A. A., Mortazavi, Y., . . . Hedlund, J. (2015). A simple method for blocking defects in zeolite membranes (ed.). Paper presented at . Journal of Membrane Science, 489, 270-274
Open this publication in new window or tab >>A simple method for blocking defects in zeolite membranes
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2015 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 489, p. 270-274Article in journal (Refereed) Published
Abstract [en]

The abatement of defects in zeolite membranes is essential for achieving high selectivity. In the present work, a simple and effective method for blocking defects in ultra-thin (ca. 0.5 μm) MFI zeolite membranes has been developed. The method is based on deposition of an ultra-thin (∼15 nm) layer of amorphous silica on the top surface of the membrane. Permporometry data indicated that the amount of defects, especially defects larger than 4 nm, in the membranes was significantly reduced after the modification. In mixture separation experiments, the CO2/H2 separation factor increased dramatically after blocking the defects in a defective membrane that was selected for the experiments. For instance, at 263 K and 9 bar feed pressure, the CO2/H2 separation factor increased from 8.5 to 36 after modification of the membrane, whereas the CO2 flux only decreased by ca. 40%.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-7226 (URN)10.1016/j.memsci.2015.04.038 (DOI)000355209300032 ()2-s2.0-84938496874 (Scopus ID)58f3c157-abda-4f09-9571-e3ea491e7be5 (Local ID)58f3c157-abda-4f09-9571-e3ea491e7be5 (Archive number)58f3c157-abda-4f09-9571-e3ea491e7be5 (OAI)
Note
Validerad; 2015; Nivå 2; 20150413 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Ye, P., Korelskiy, D., Grahn, M. & Hedlund, J. (2015). Cryogenic air separation at low pressure using MFI membranes (ed.). Paper presented at . Journal of Membrane Science, 487, 135-140
Open this publication in new window or tab >>Cryogenic air separation at low pressure using MFI membranes
2015 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 487, p. 135-140Article in journal (Refereed) Published
Abstract [en]

Ultra-thin MFI membranes were for the first time evaluated for air separation at low feed pressures ranging from 100 to 1000 mbar at cryogenic temperature. The membrane separation performance at optimum temperature at all investigated feed pressures was well above the Robeson upper bound for polymeric membranes at near room temperature. The O2/N2 separation factor at optimum temperature increased as the feed pressure was decreased and reached 5.0 at 100 mbar feed pressure and a membrane temperature of 67 K. The corresponding membrane selectivity was 6.3, and the O2 permeance was as high as 8.6×10−7 mol m−2 s−1 Pa−1. This permeance was about 100 times higher than that reported for promising polymeric membranes. The membrane selectivity and high O2 permeance was most likely a result of O2/N2 adsorption selectivity. The increase in O2/N2 separation factor with decreasing pressure and temperature was probably due to increased adsorption selectivity at reduced temperature. This work has demonstrated the potential of MFI zeolite membranes for O2/N2 separations at cryogenic temperature.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-10747 (URN)10.1016/j.memsci.2015.03.063 (DOI)000354490700015 ()2-s2.0-84928169403 (Scopus ID)99a46e1f-6cce-41c3-84db-bcca182f12bc (Local ID)99a46e1f-6cce-41c3-84db-bcca182f12bc (Archive number)99a46e1f-6cce-41c3-84db-bcca182f12bc (OAI)
Note
Validerad; 2015; Nivå 2; 20150316 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Korelskiy, D., Ye, P., Fouladvand, S., Karimi, S., Sjöberg, E. & Hedlund, J. (2015). Efficient ceramic zeolite membranes for CO2/H2 separation (ed.). Paper presented at . Journal of Materials Chemistry A, 2015(3), 12500-12506
Open this publication in new window or tab >>Efficient ceramic zeolite membranes for CO2/H2 separation
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2015 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2015, no 3, p. 12500-12506Article in journal (Refereed) Published
Abstract [en]

Membranes are considered one of the most promising technologies for CO2 separation from industrially important gas mixtures like synthesis gas or natural gas. In order for the membrane separation process to be efficient, membranes, in addition to being cost-effective, should be durable and possess high flux and sufficient selectivity. Current CO2-selective membranes are low flux polymeric membranes with limited chemical and thermal stability. In the present work, robust and high flux ceramic MFI zeolite membranes were prepared and evaluated for separation of CO2 from H2, a process of great importance to synthesis gas processing, in a broad temperature range of 235–310 K and at an industrially relevant feed pressure of 9 bar. The observed membrane separation performance in terms both selectivity and flux was superior to that previously reported for the state-of-the-art CO2-selective zeolite and polymeric membranes. Our initial cost estimate of the membrane modules showed that the present membranes were economically viable. We also showed that the ceramic zeolite membrane separation system would be much more compact than a system relying on polymeric membranes. Our findings therefore suggest that the developed high flux ceramic zeolite membranes have great potential for selective, cost-effective and sustainable removal of CO2 from synthesis gas.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-10306 (URN)10.1039/C5TA02152A (DOI)000355736700047 ()2-s2.0-84930959021 (Scopus ID)91a22b0f-02d2-4414-8c78-7364ca1431e0 (Local ID)91a22b0f-02d2-4414-8c78-7364ca1431e0 (Archive number)91a22b0f-02d2-4414-8c78-7364ca1431e0 (OAI)
Note
Validerad; 2015; Nivå 2; 20150514 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Sjöberg, E., Barnes, S., Korelskiy, D. & Hedlund, J. (2015). MFI membranes for separation of carbon dioxide from synthesis gas at high pressures (ed.). Paper presented at . Journal of Membrane Science, 486, 132-137
Open this publication in new window or tab >>MFI membranes for separation of carbon dioxide from synthesis gas at high pressures
2015 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 486, p. 132-137Article in journal (Refereed) Published
Abstract [en]

Membranes are considered to be one of the most promising technologies for simple and energy efficient removal of carbon dioxide from gas mixtures. In the present work, MFI membranes with different Si/Al ratios and counter-ions were evaluated for separation of carbon dioxide from synthesis gas, i.e. a mixture of carbon dioxide and hydrogen. Single gas permeation experiments were also carried out. These membranes consisted of a 0.5 µm thick MFI film grown on graded alumina supports. The feed pressure was varied between 3 and 8 bar and the permeate pressure was kept constant at 1 bar, while the temperature was varied in a range of 273–350 K. The silicalite-1 membrane showed the best overall carbon dioxide separation performance, in terms of flux and separation factor, when compared with NaZSM-5 and BaZSM-5 membranes. The silicalite-1 membrane displayed a CO2/H2 separation factor of 31, with a carbon dioxide flux of ca. 560 kg m−2 h−1 at 8 bar feed pressure and a temperature of 273 K. The higher performance of the silicalite-1 membrane was attributed to a more suitable CO2 adsorption isotherm, which resulted in larger difference in fractional surface loading of CO2 between the feed and permeate side for this type of membrane, and consequently higher CO2 flux and CO2/H2 separation factor. Accordingly, the difference in membrane performance was larger at low temperature (273 K), while at elevated temperatures, the CO2/H2 separation factor decreased for all membranes and the difference between the membrane types diminished, as a result of decreased carbon dioxide adsorption.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-16142 (URN)10.1016/j.memsci.2015.03.041 (DOI)000353480700013 ()2-s2.0-84926432968 (Scopus ID)fbc07627-0a0a-4ac6-95d5-8fba3ff78b65 (Local ID)fbc07627-0a0a-4ac6-95d5-8fba3ff78b65 (Archive number)fbc07627-0a0a-4ac6-95d5-8fba3ff78b65 (OAI)
Note
Validerad; 2015; Nivå 2; 20150317 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Leppäjärvi, T., Malinen, I., Korelskiy, D., Kangas, J., Hedlund, J. & Tanskanen, J. (2015). Pervaporation of Ethanol/Water Mixtures through a High-silica MFI Membrane: Comparison of Different Semi-empirical Mass Transfer Models (ed.). Paper presented at . Periodica Polytechnica. Chemical Engineering, 59(2), 111-123
Open this publication in new window or tab >>Pervaporation of Ethanol/Water Mixtures through a High-silica MFI Membrane: Comparison of Different Semi-empirical Mass Transfer Models
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2015 (English)In: Periodica Polytechnica. Chemical Engineering, ISSN 0324-5853, Vol. 59, no 2, p. 111-123Article in journal (Refereed) Published
Abstract [en]

Pervaporation of binary ethanol/water solutions of 5-10 wt.% ethanol was studied experimentally through a thin supported high-silica MFI zeolite membrane of hydrophobic character in the temperature range of 30-70 degrees C. The fluxes obtained were very high, 2-14 kg m(-2)h(-1) with ethanol/water separation factors of 4-7. The loss of effective driving force was significant in the supporting layers, which limited the membrane performance. The correlation between the experimental data and three different semi-empirical mass-transfer models was examined The correlation was good especially when the driving force for mass-transfer was determined based solely on bulk feed, or the bulk feed and permeate conditions together Somewhat lower correlation was observed when the driving force was corrected with the effect of support resistance. This was most likely due to the inaccuracies of the used mass transfer parameters in the support. The investigated semi-empirical models can be applied for initial stage process design purposes.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-11079 (URN)10.3311/PPch.7665 (DOI)000356633600002 ()2-s2.0-84939120777 (Scopus ID)9fd64cbb-5fcc-426e-8f35-4fd66c5ac316 (Local ID)9fd64cbb-5fcc-426e-8f35-4fd66c5ac316 (Archive number)9fd64cbb-5fcc-426e-8f35-4fd66c5ac316 (OAI)
Note
Validerad; 2015; Nivå 2; 20141020 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Akhtar, F., Sjöberg, E., Korelskiy, D., Rayson, M., Hedlund, J. & Bergström, L. (2015). Preparation of graded silicalite-1 substrates for all-zeolite membranes with excellent CO2/H2 separation performance (ed.). Paper presented at . Journal of Membrane Science, 493, 206-211
Open this publication in new window or tab >>Preparation of graded silicalite-1 substrates for all-zeolite membranes with excellent CO2/H2 separation performance
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2015 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 493, p. 206-211Article in journal (Refereed) Published
Abstract [en]

raded silicalite-1 substrates with a high gas permeability and low surface roughness have been produced by pulsed current processing of a thin coating of a submicron silicalite-1 powder onto a powder body of coarser silicalite-1 crystals. Thin zeolite films have been hydrothermally grown onto the graded silicalite-1 support and the all-zeolite membranes display an excellent CO2/H2 separation factor of 12 at 0 °C and a CO2 permeance of 21.3×10-7 mol m-2 s-1 Pa-1 for an equimolar CO2/H2 feed at 505 kPa and 101 kPa helium sweep gas. Thermal cracking estimates based on calculated surface energies and measured thermal expansion coefficients suggest that all-zeolite membranes with a minimal thermal expansion mismatch between the graded substrate and the zeolite film should remain crack-free during thermal cycling and the critical calcination step.

National Category
Other Materials Engineering Chemical Process Engineering
Research subject
Engineering Materials; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-7494 (URN)10.1016/j.memsci.2015.06.020 (DOI)000360554300021 ()2-s2.0-84937053154 (Scopus ID)5e4f9cc9-1c4c-4998-94e9-a3f2fb37570b (Local ID)5e4f9cc9-1c4c-4998-94e9-a3f2fb37570b (Archive number)5e4f9cc9-1c4c-4998-94e9-a3f2fb37570b (OAI)
Note
Validerad; 2015; Nivå 2; 20150612 (dankor)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2459-7932

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