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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
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 2050-7488Article in journal (Refereed) Epub ahead of print
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)
Available from: 2019-04-11 Created: 2019-04-11 Last updated: 2019-04-11
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: 2019-04-12Bibliographically 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
Yu, L., Grahn, M. & Hedlund, J. (2018). Ultra-thin MFI membranes for removal of C3+ hydrocarbons from methane. Journal of Membrane Science, 551, 254-260
Open this publication in new window or tab >>Ultra-thin MFI membranes for removal of C3+ hydrocarbons from methane
2018 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 551, p. 254-260Article in journal (Refereed) Published
Abstract [en]

The removal of propane and heavier hydrocarbons (C3+) from natural gas is an important part of natural gas upgrading. In the present work, ultra-thin MFI zeolite membranes with a thickness of 400 nm and an estimated Si/Al ratio of 152 were evaluated for separation of C3H8 and n-C4H10 from binary and ternary mixtures with CH4. The membranes were selective towards the heavier hydrocarbons and showed high permeance at all investigated temperatures. At room temperature, the n-C4H10/CH4 separation selectivity was 25, coupled with an n-C4H10 permeance of 31 × 10−7 mol m−2 s−1 Pa−1 for a 10/90 n-C4H10/CH4 binary feed mixture. As the temperature was decreased to 281 K, the separation selectivity increased to as high as 55 with an n-C4H10 permeance of 25 × 10−7 mol m−2 s−1 Pa−1. The separation selectivities for a 10/90 C3H8/CH4 binary mixture were 9.5 and 19, with C3H8 permeances as high as 54 and 37 × 10−7 mol m−2 s−1 Pa−1 at 297 and 271 K, respectively. The higher selectivities observed for n-C4H10 containing mixtures was ascribed to stronger adsorption of n-C4H10 than C3H8 in MFI, thus resulting in higher adsorption selectivities of the n-C4H10 containing mixtures over CH4. For a 10/10/80 n-C4H10/C3H8/CH4 ternary mixture, the highest sum selectivity of (n-C4H10 + C3H8)/CH4 was 48 and the corresponding sum permance of (n-C4H10 + C3H8) was 26 × 10−7 mol m−2s−1 Pa−1 at 283 K, which were similar to the separation results of n-C4H10/CH4 binary mixture at the same conditions. The n-C4H10/CH4 and C3H8/CH4 separation selectivities from the ternary mixture were of course lower, but still as high as 32 and 16 at 283 K, with n-C4H10 and C3H8 permeances of 17 and 8 × 10−7 mol m−2 s−1 Pa−1, respectively. The results show that ultra-thin MFI zeolite membranes are promising candidates for separation of C3+ hydrocarbons from natural gas. 

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-67692 (URN)10.1016/j.memsci.2018.01.054 (DOI)000426032100026 ()2-s2.0-85041461960 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-02-19 (svasva)

Available from: 2018-02-19 Created: 2018-02-19 Last updated: 2018-07-18Bibliographically approved
Grahn, M., Higman, C., Holmgren, A. & Hedlund, J. (2017). Efficient syngas upgrading with high flux zeolite membranes. In: 34th Annual International Pittsburgh Coal Conference: Coal - Energy, Environment and Sustainable Development, PCC 2017. Paper presented at 34th Annual International Pittsburgh Coal Conference: Coal - Energy, Environment and Sustainable Development, PCC 2017, Pittsburgh, United States, 5-8 September 2017. International Pittsburgh Coal Conference
Open this publication in new window or tab >>Efficient syngas upgrading with high flux zeolite membranes
2017 (English)In: 34th Annual International Pittsburgh Coal Conference: Coal - Energy, Environment and Sustainable Development, PCC 2017, International Pittsburgh Coal Conference , 2017Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
International Pittsburgh Coal Conference, 2017
National Category
Chemical Engineering
Research subject
Chemical Technology; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-69010 (URN)
Conference
34th Annual International Pittsburgh Coal Conference: Coal - Energy, Environment and Sustainable Development, PCC 2017, Pittsburgh, United States, 5-8 September 2017
Available from: 2018-05-31 Created: 2018-05-31 Last updated: 2018-05-31Bibliographically approved
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: 2018-11-16Bibliographically approved
Ohlin, L., Farzaneh, A., Holmgren, A., Hedlund, J. & Grahn, M. (2017). Ternary Adsorption of Methane, Water and Carbon Dioxide in Zeolite Na-ZSM-5 Studied Using in Situ ATR-FTIR Spectroscopy. The Journal of Physical Chemistry C, 121(27), 14703-14711
Open this publication in new window or tab >>Ternary Adsorption of Methane, Water and Carbon Dioxide in Zeolite Na-ZSM-5 Studied Using in Situ ATR-FTIR Spectroscopy
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2017 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 27, p. 14703-14711Article in journal (Refereed) Published
Abstract [en]

The main component in biogas and natural gas is methane but these gases also contain water and carbon dioxide that often have to be removed in order to increase the calorific value of the gas. Membrane and adsorbent-based technologies using zeolites are interesting alternatives for efficient separation of these components. To develop efficient processes, it is essential to know the adsorption properties of the zeolite. In the present work, adsorption of methane, carbon dioxide and water from ternary mixtures in high silica zeolite Na-ZSM-5 was studied using in-situ ATR (Attenuated Total Reflection) – FTIR (Fourier Transform Infrared) spectroscopy. Adsorbed concentrations were extracted from the infrared spectra and the obtained loadings were compared to values predicted by the Ideal Adsorbed Solution Theory (IAST). The IAST could not fully capture the adsorption behavior of this ternary mixture, indicating that the adsorbed phase is not behaving as an ideal mixture. The CO2/CH4 adsorption selectivities determined for the ternary mixtures were compared to selectivities determined for binary mixtures in our previous work, indicating that the presence of water slightly improves the CO2/CH4 adsorption selectivity at lower temperatures. Further, the results show that water and carbon dioxide are adsorbed preferentially over methane in high silica zeolite Na-ZSM-5.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-64397 (URN)10.1021/acs.jpcc.7b04405 (DOI)000405761600035 ()2-s2.0-85024101175 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-08-08 (rokbeg)

Available from: 2017-06-22 Created: 2017-06-22 Last updated: 2018-05-28Bibliographically approved
Yu, L., Grahn, M., Ye, P. & Hedlund, J. (2017). Ultra-thin MFI membranes for olefin/nitrogen separation. Journal of Membrane Science, 524, 428-435
Open this publication in new window or tab >>Ultra-thin MFI membranes for olefin/nitrogen separation
2017 (English)In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 524, p. 428-435Article in journal (Refereed) Published
Abstract [en]

The recovery of light hydrocarbons such as propylene and ethylene from vent streams in polymer plants is desirable since it opens up for more efficient conversion of the monomers with high economic value. Consequently, polymer membrane vapour-gas separation systems have been used for this purpose for decades [1,2]. However, an alternative is zeolite membranes. In this work, ultra-thin MFI zeolite membranes (0.5 µm) were used to separate propylene or ethylene from binary 20/80 olefin/nitrogen mixtures at different temperatures. The membranes were olefin selective with high permeance at all investigated temperatures. At room temperature, the permeance of propylene was 22×10-7 mol m-2 s-1 Pa-1 and the separation factor was 43, which corresponds to a separation selectivity of around 80. For a mixture of 20 mol.% ethylene in nitrogen, the maximum separation factor was 6 (corresponds to a separation selectivity of 8.4) at 277 K with an ethylene permeance of 57×10-7 mol m-2 s-1 Pa-1. The membrane selectivity was governed by more extensive adsorption of olefin, especially propylene, as compared to nitrogen. Comparing with ethylene, propylene has higher heat of adsorption, which probably caused the higher propylene/nitrogen selectivity compared to ethylene/nitrogen selectivity. The permeance and the selectivity for propylene were much higher than for commercial polymeric membranes. For ethylene, the permeance was much higher, and the selectivity was comparable to commercial polymeric membranes. Modelling showed that the pressure drop over the support limited the flux through the membranes especially at higher temperatures and in particular for the ethylene/nitrogen system with high flux. Further, modelling indicated that the result obtained at high temperatures, where the flux was high, was also affected by concentration polarization. However, for the propylene/nitrogen system at the optimum separation temperature, the pressure drop over the support and the concentration polarisation were small. The results show that ultra-thin MFI zeolite membranes are promising candidates for light olefins/nitrogen separation in polymer plants.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Chemical Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-60705 (URN)10.1016/j.memsci.2016.11.077 (DOI)000392769000045 ()2-s2.0-85002293040 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-02 (andbra)

Available from: 2016-11-27 Created: 2016-11-27 Last updated: 2018-09-13Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1053-4623

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