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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
Yu, L., Holmgren, A. & Hedlund, J. (2019). A novel method for fabrication of high-flux zeolite membranes on supports with arbitrary geometry. Journal of Materials Chemistry A, 7(17), 10325-10330
Open this publication in new window or tab >>A novel method for fabrication of high-flux zeolite membranes on supports with arbitrary geometry
2019 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10325-10330Article in journal (Refereed) Published
Abstract [en]

A novel procedure for the preparation of high-flux zeolite membranes was developed. This method relies on rendering the support hydrophobic, and thereby protected from the synthesis mixture and invasion of the support pores, while the cationic polymer on the surface still allowed deposition of zeolite seeds. Both high-flux MFI and CHA zeolite films were grown on both discs and tubular supports, which illustrates the applicability of the method to arbitrary membrane geometries. Typically, MFI disc membranes showed a very high CO2permeance of 85 × 10−7 mol m−2 s−1 Pa−1 and a CO2/H2 separation selectivity of 56 at 278 K and CHA disc membranes showed a very high CO2 permeance of 79 × 10−7 mol m−2 s−1 Pa−1 and a CO2/CH4 separation selectivity of 76 at 249 K. As the method is applicable to supports with complex geometries, it is suitable for preparation of membranes for industrial applications.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-73583 (URN)10.1039/C9TA00789J (DOI)000472183200016 ()2-s2.0-85064990509 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-24 (johcin)

Available from: 2019-04-11 Created: 2019-04-11 Last updated: 2019-07-10Bibliographically approved
Yu, L., Nobandegani, M. S., Holmgren, A. & Hedlund, J. (2019). Highly permeable and selective tubular zeolite CHA membranes. Journal of Membrane Science, 588, Article ID 117224.
Open this publication in new window or tab >>Highly permeable and selective tubular zeolite CHA membranes
2019 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 588, article id 117224Article in journal (Refereed) Published
Abstract [en]

Highly permeable and selective tubular zeolite CHA membranes with a thickness of about 450 nm and a length of 100 mm and an inner diameter of 7 mm were evaluated by single gas permeation experiments and for separation of an equimolar CO2/CH4 mixture. The membranes displayed high H2 and CO2 single gas permeances of 55 × 10−7 mol m−2 s−1 Pa−1 and 94 × 10−7 mol m−2 s−1 Pa−1, respectively, and a very low SF6 permeance of 3 × 10−9 mol m−2 s−1 Pa−1. The highest observed mixture separation factor was 99 with CO2 permeance of 60 × 10−7 mol m−2 s−1 Pa−1 at a feed pressure of 5 bar and permeate pressure of 0.12 bar. The corresponding CO2flux was 1.46 mol m−2 s−1. The highest observed flux was 1.98 mol m−2 s−1 with a separation factor of 52 at a feed pressure of 10 bar and permeate pressure of 0.12 bar at room temperature. To the best of our knowledge, this is the first report describing highly permeable and selective tubular CHA membranes. The results indicate that the membranes have a great potential for industrial separation of CO2from natural gas and biogas.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Tubular zeolite CHA membrane, Gas separation, High permeance, Biogas, Natural gas
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-75258 (URN)10.1016/j.memsci.2019.117224 (DOI)000481577200017 ()
Note

Validerad;2019;Nivå 2;2019-07-08 (johcin)

Available from: 2019-07-08 Created: 2019-07-08 Last updated: 2019-09-09Bibliographically approved
Faisal, A., Holmlund, M., Ginesy, M., Holmgren, A., Enman, J., Hedlund, J. & Grahn, M. (2019). Recovery of l-Arginine from Model Solutions and Fermentation Broth Using Zeolite-Y Adsorbent. ACS Sustainable Chemistry & Engineering, 7(9), 8900-8907
Open this publication in new window or tab >>Recovery of l-Arginine from Model Solutions and Fermentation Broth Using Zeolite-Y Adsorbent
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2019 (English)In: ACS Sustainable Chemistry & Engineering, ISSN 2168-0485, Vol. 7, no 9, p. 8900-8907Article in journal (Refereed) Published
Abstract [en]

Arginine was produced via fermentation of sugars using the engineered microorganism Escherichia coli. Zeolite-Y adsorbents in the form of powder and extrudates were used to recover arginine from both a real fermentation broth and aqueous model solutions. An adsorption isotherm was determined using model solutions and zeolite-Y powder. The saturation loading was determined to be 0.2 g/g using the Sips model. Arginine adsorbed from a real fermentation broth using either zeolite-Y powder or extrudates both showed a maximum loading of 0.15 g/g at pH 11. This adsorbed loading is very close to the corresponding value obtained from the model solution showing that under the experimental conditions the presence of additional components in the broth did not have a significant effect on the adsorption of arginine. Furthermore, a breakthrough curve was determined for extrudates using a 1 wt % arginine model solution. The selectivity for arginine over ammonia and alanine from the real fermentation broth at pH 11 was 1.9 and 8.3, respectively, for powder, and 1.0, and 4.1, respectively, for extrudates. To the best of our knowledge, this is the first time recovery of arginine from real fermentation broths using any type of adsorbent has been reported.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
Keywords
Arginine, FAU, Fermentation broth, Escherichia coli, Adsorption, Selectivity, Breakthrough
National Category
Chemical Process Engineering Bioprocess Technology
Research subject
Chemical Technology; Biochemical Process Engineering
Identifiers
urn:nbn:se:ltu:diva-73954 (URN)10.1021/acssuschemeng.9b00918 (DOI)000467351200095 ()2-s2.0-85065476739 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-05-27 (oliekm)

Available from: 2019-05-15 Created: 2019-05-15 Last updated: 2019-08-19Bibliographically approved
Grahn, M., Faisal, A., Öhrman, O. G. ., Zhou, M., Signorile, M., Crocellà, V., . . . Hedlund, J. (2019). Small ZSM-5 crystals with low defect density as an effective catalyst for conversion of methanol to hydrocarbons. Catalysis Today
Open this publication in new window or tab >>Small ZSM-5 crystals with low defect density as an effective catalyst for conversion of methanol to hydrocarbons
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2019 (English)In: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308Article in journal (Refereed) Epub ahead of print
Abstract [en]

This work presents the synthesis of nearly defect-free ZSM-5 nanosized crystals, prepared in fluoride medium by seeding with silicalite-1. This material was carefully characterized and its catalytic performances in the methanol to hydrocarbons (MTH) reaction were assessed. Such fluoride-based material was compared to a reference ZSM-5, produced through a conventional alkaline synthesis but from the same seeding. Despite both the materials show closely identical morphology and they have a comparable acid site population, the catalyst prepared using the fluoride route showed significantly longer lifetime in MTH compared to the catalyst prepared using conventional synthesis at high pH. The slower deactivation for the samples prepared using the fluoride route was ascribed, thanks to a thorough in situ IR spectroscopy study, to its lower density of internal defects. According to the UV-Raman characterization of coke on the spent catalyst, the fluoride-based ZSM-5 catalyst produces less molecular coke species, most probably because of the absence of enlarged cavities/channels as due to the presence of internal defects. On the basis of these observations, the deactivation mechanism in the ZSM-5 synthesized by fluoride medium could be mostly related to the deposition of an external layer of bulk coke, whereas in the alkali-synthesized catalyst an additional effect from molecular coke accumulating within the porous network accelerates the deactivation process.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
ZSM-5, defects, hydrocarbons, deactivation, MTH, IR spectroscopy, OH groups
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-76102 (URN)10.1016/j.cattod.2019.09.023 (DOI)2-s2.0-85073006485 (Scopus ID)
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-11-26
Nabavi, M. S., Zhou, M., Mouzon, J., Grahn, M. & Hedlund, J. (2019). Stability of colloidal ZSM-5 catalysts synthesized in fluoride and hydroxide media. Microporous and Mesoporous Materials, 278, 167-174
Open this publication in new window or tab >>Stability of colloidal ZSM-5 catalysts synthesized in fluoride and hydroxide media
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2019 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 278, p. 167-174Article in journal (Refereed) Published
Abstract [en]

ZSM-5 zeolite crystals with carefully controlled thicknesses in the range 20–110 nm, i.e. in the colloidal domain, were synthesized in fluoride and hydroxide media. The crystals were treated in steam at high temperature to evaluate the stability and evaluated by SEM, XRD, NMR and NH3-TPD. The results showed that the framework of crystals synthesized in fluoride media was more stable than the framework of crystals synthesized in hydroxide media. This should be an effect of lower concentration of structural defects and silanol groups in the former zeolites as reported by other groups. However, independently of the synthesis conditions, all crystals dealuminated rapidly when treated with steam at the conditions investigated in the present work.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
ZSM-5, Catalyst, Stability, Framework, Steam, Dealumination
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-71897 (URN)10.1016/j.micromeso.2018.11.007 (DOI)000459841900020 ()2-s2.0-85057248871 (Scopus ID)
Note

Validerad;2019;Nivå 2;2018-12-05 (svasva)

Available from: 2018-12-05 Created: 2018-12-05 Last updated: 2019-11-26Bibliographically approved
Yu, L., Fouladvand, S., Grahn, M. & Hedlund, J. (2019). Ultra-thin MFI membranes with different Si/Al ratios for CO2/CH4 separation. Microporous and Mesoporous Materials, 284, 258-269
Open this publication in new window or tab >>Ultra-thin MFI membranes with different Si/Al ratios for CO2/CH4 separation
2019 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 284, p. 258-269Article in journal (Refereed) Published
Abstract [en]

Ultra-thin MFI zeolite membranes with different Si/Al ratios (152, 47 and 26) were prepared on graded α-alumina supports in the presence of organic template molecules and evaluated for separation of equimolar CO2/CH4 mixtures at temperatures from 315 to 249 K. The thicknesses of all membranes were less than 500 nm and permporometry showed that the number and size of defects were low for the two membranes with the highest Si/Al ratio (152 and 47). The membrane with the lowest Si/Al ratio (26) also had low amounts of defects in the mesopore range, but did have a few macropore defects. All membranes showed very high CO2permeances in the entire temperature range studied and the permeances increased with increasing temperature. The CO2 permances were also correlated to the Si/Al ratio of the membranes. The higher permeances was observed for membranes with higher Si/Al ratio. The highest observed CO2 permeance was 142 × 10−7 mol s−1 m−2Pa−1 at room temperature for the membrane with Si/Al = 152. The separation factor, on the other hand, increased with decreasing temperature for the two membranes with the highest Si/Al ratio (152 and 47), but for the membrane with a Si/Al ratio of 26, the separation factor went through a maximum at ca. 270 K. The highest separation factor observed was 7.1 at 249 K for the membrane with Si/Al = 47. These observations are consistent with an adsorption controlled separation mechanism.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
MFI zeolite membranes, Si/Al ratios, CO2/CH4 separation, High permeance, Natural gas, Biogas
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-73759 (URN)10.1016/j.micromeso.2019.04.042 (DOI)000469893200031 ()2-s2.0-85064689829 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-04-30 (johcin)

Available from: 2019-04-24 Created: 2019-04-24 Last updated: 2019-06-20Bibliographically approved
Wei, J., Geng, S., Sarmad, S., Hedlund, J. & Oksman, K. (2018). Adsorption of Carbon Dioxide on Cellulose Nanofiber-Based Monolithic Cryogels Impregnated with Acetylated Cellulose Nanocrystals. In: : . Paper presented at 72nd Forest Products Society (FPS) International Convention, Madison, Wisconsin, USA, June 11–14, 2018.
Open this publication in new window or tab >>Adsorption of Carbon Dioxide on Cellulose Nanofiber-Based Monolithic Cryogels Impregnated with Acetylated Cellulose Nanocrystals
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2018 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Nanocellulose materials with large surface area are prospective as substrates to obtain low-carbon-footprint CO2 adsorbents. In this study, ice-templating was conducted to prepare cellulose nanofibers (CNFs) based cryogels with monolithic structure, which can provide a good mass flow during the adsorption process. Furthermore, since acetyl groups have shown relatively high CO2 affinity, cellulose nanocrystals (CNCs) were acetylated and then impregnated into the cryogel to improve its CO2 capacity. Meanwhile, different amounts of cellulose acetate (CA) were impregnated and characterized as references. The success of the acetylation of CNCs was confirmed by Fourier-transform infrared spectroscopy (FTIR) and the degree of substitution was determined by titration. Results from the scanning electron microscopy (SEM) demonstrated that the monolithic structure was maintained after the impregnation. According to the breakthrough test, the cryogel impregnated with 0.1g of acetylated CNCs exhibits a much higher CO2 capacity with a value of 1.49 mmol/g compared to the CA impregnated ones. The mechanical properties of the cryogels were also evaluated by compression testing, revealing the outstanding reinforcing effect of acetylated CNCs.

Keywords
Nanocellulose, cryogel, adsorption, carbon dioxide, acetylation
National Category
Chemical Process Engineering Bio Materials
Research subject
Wood and Bionanocomposites; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-71083 (URN)
Conference
72nd Forest Products Society (FPS) International Convention, Madison, Wisconsin, USA, June 11–14, 2018
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2019-01-16Bibliographically approved
Carvalho, L., Furusjö, E., Ma, C., Ji, X., Lundgren, J., Hedlund, J., . . . Wetterlund, E. (2018). Alkali enhanced biomass gasification with in situ S capture and a novel syngas cleaning: Part 2: Techno-economic analysis. Energy, 165(Part B), 471-482
Open this publication in new window or tab >>Alkali enhanced biomass gasification with in situ S capture and a novel syngas cleaning: Part 2: Techno-economic analysis
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2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 165, no Part B, p. 471-482Article in journal (Refereed) Published
Abstract [en]

Previous research has shown that alkali addition has operational advantages in entrained flow biomass gasification and allows for capture of up to 90% of the biomass sulfur in the slag phase. The resultant low-sulfur content syngas can create new possibilities for syngas cleaning processes. The aim was to assess the techno-economic performance of biofuel production via gasification of alkali impregnated biomass using a novel gas cleaning systemcomprised of (i) entrained flow catalytic gasification with in situ sulfur removal, (ii) further sulfur removal using a zinc bed, (iii) tar removal using a carbon filter, and (iv) CO2 reductionwith zeolite membranes, in comparison to the expensive acid gas removal system (Rectisol technology). The results show that alkali impregnation increases methanol productionallowing for selling prices similar to biofuel production from non-impregnated biomass. It was concluded that the methanol production using the novel cleaning system is comparable to the Rectisol technology in terms of energy efficiency, while showing an economic advantagederived from a methanol selling price reduction of 2–6 €/MWh. The results showed a high level of robustness to changes related to prices and operation. Methanol selling prices could be further reduced by choosing low sulfur content feedstocks.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Biomass gasification, Catalysis, Entrained-flowBio-methanol, Techno-economic analysis
National Category
Energy Systems Energy Engineering Chemical Process Engineering
Research subject
Energy Engineering; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-68206 (URN)10.1016/j.energy.2018.09.159 (DOI)000455171600039 ()2-s2.0-85056197830 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-12-03 (johcin)

Available from: 2018-04-05 Created: 2018-04-05 Last updated: 2019-01-25Bibliographically approved
Zhou, M. & Hedlund, J. (2018). Facile Preparation of Hydrophobic Colloidal MFI and CHA Crystals and Oriented Ultra-thin Films. Angewandte Chemie International Edition, 130(34), 11132-11136
Open this publication in new window or tab >>Facile Preparation of Hydrophobic Colloidal MFI and CHA Crystals and Oriented Ultra-thin Films
2018 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 130, no 34, p. 11132-11136Article in journal (Refereed) Published
Abstract [en]

We report novel routes for synthesis of defect-free, hydrophobic and monodispersed 10 nm (5 unit cells) thick MFI crystals and 100 nm CHA crystals. The crystals are obtained in high yield and display very high 1-butanol adsorption from aqueous solution. These crystals are assembled in monolayers for the growth of ultra-thin and uniformly oriented films with thicknesses of 36 nm and 330 nm, respectively, using a synthesis gel in the form of a powder. This method is very simple and may open up for industrial preparation of materials with improved performances.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-70084 (URN)10.1002/anie.201806502 (DOI)000442863700029 ()29969534 (PubMedID)
Note

Validerad;2018;Nivå 2;2018-08-14 (andbra)

Available from: 2018-07-06 Created: 2018-07-06 Last updated: 2018-09-10Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1053-4623

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