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Karimi, Somayeh
Publications (4 of 4) Show all publications
Karimi, S., Mortazavi, Y., Khodadadi, A. A., Holmgren, A., Korelskiy, D. & Hedlund, J. (2020). Functionalization of silica membranes for CO2 separation. Separation and Purification Technology, 235, Article ID 116207.
Open this publication in new window or tab >>Functionalization of silica membranes for CO2 separation
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2020 (English)In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 235, article id 116207Article in journal (Refereed) Published
Abstract [en]

Five organic CO2-philic functional groups were incorporated in silica matrixes for preparation of functionalized silica membranes to explore the CO2 separation performance. Chemical groups including acetate, trifluoromethyl, methacrylate, urea and vinyl groups were anchored in the silica network using the co-condensation method.

The information from 29Si solid-state NMR and FTIR analyses indicates the successful formation of a covalent bond between functional groups and the silica network. The thickness of the functionalized silica layers was measured by SEM and the thermal stability of the organic groups was determined by thermogravimetric analysis (TGA).

The gas permeance and mixed gas selectivity of CO2/N2 was measured in the temperature range of 253–373 K with a feed pressure of 9 bar. A maximum selectivity of as high as 10 was observed for a trifluoromethyl functionalized silica membrane with a CO2 permeance of 5.5 × 10−7 mol s−1 m−2 Pa−1. Permporometry measurements indicated that the contribution of flow through micropores to the total flow for all the functionalized silica membranes varied between 62 and 82%. All membranes were CO2 selective.

 

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
CO2 separation, Functionalized silica membrane, Co-condensation
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-76487 (URN)10.1016/j.seppur.2019.116207 (DOI)2-s2.0-85073520358 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-10-23 (johcin)

Available from: 2019-10-23 Created: 2019-10-23 Last updated: 2019-10-29Bibliographically 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
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
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