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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, 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
Yan, B., Yu, S., Zeng, C., Yu, L., Wang, C. & Zhang, L. (2019). Binderless zeolite NaX microspheres with enhanced CO2 adsorption selectivity. Microporous and Mesoporous Materials, 278, 267-274
Open this publication in new window or tab >>Binderless zeolite NaX microspheres with enhanced CO2 adsorption selectivity
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2019 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 278, p. 267-274Article in journal (Refereed) Published
Abstract [en]

Zeolite NaX@NaA core-shell microspheres were prepared via a post-treatment secondary growth of zeolite NaA films on outer surface of binderless zeolite NaX microspheres. The obtained core-shell microspheres were composed of intergrown octahedral NaX particles inside, with particles size of ca. 500–750 nm, and continuous zeolite NaA films on the outer surface with the thickness of about 2 μm. Higher CO2 separation performance was observed for the core-shell microspheres comparing to the parental binderless zeolite NaX microspheres. The ideal separation factors of zeolite NaX@NaA core-shell microspheres for CO2/CH4 and CO2/N2 were 13 and 47, and the adsorption selectivities for the corresponding binary mixtures were 308 and 923, significantly higher than the binderless zeolite NaX microspheres of 9 and 19 as well as 264 and 735, respectively. After K+ ion exchanging, the core-shell zeolite microspheres have even higher adsorption selectivities of 326 and 1109 for CO2/CH4 and CO2/N2 binary mixtures. The crushing strength of the binderless zeolite NaX microspheres was increased from 0.46 MPa to 3.42 MPa after the secondary growth. In addition, the growth of zeolite A film was resultant from interzeolite conversion and the interzeolite conversion was investigated by the conversion of zeolite NaX to NaA crystals in NaA membrane synthesis gel.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Zeolite, Core-shell microsphere, Membrane, Interzeolite conversion, CO2 separation
National Category
Chemical Engineering Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-72574 (URN)10.1016/j.micromeso.2018.12.002 (DOI)000459841900032 ()2-s2.0-85057613263 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-01-25 (svasva)

Available from: 2019-01-15 Created: 2019-01-15 Last updated: 2019-04-12Bibliographically 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
Cai, J., Jiang, L., Huaming, W., Chongqing, W., Yu, L. & Zhang, L. (2019). Preparation of carbon/cobalt composite from phenolic resin and ZIF-67 for efficient tannic acid adsorption. Microporous and Mesoporous Materials, 287, 9-17
Open this publication in new window or tab >>Preparation of carbon/cobalt composite from phenolic resin and ZIF-67 for efficient tannic acid adsorption
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2019 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 287, p. 9-17Article in journal (Refereed) Published
Abstract [en]

In the present work, a carbon/cobalt composite was prepared and evaluated for adsorption of ecologically harmful tannic acid (TA). The composite was prepared by simply mixing phenolic resin with ZIF-67 and following by carbonization. TEM and SEM images showed that ZIF-67 was etched by phenolic resin and cobalt nanoparticles were formed and evenly distributed in carbon. Macroporous structure was generated between the carbonized phenolic resin and ZIF-67. N2 adsorption-desorption isotherms results exhibited that the composite also had both micro- and meso-pores (average pore size of 5 nm) with a high surface area of 393 m2 g−1. Porous structure and evenly distributed cobalt nanoparticles facilitated the diffusion and adsorption of TA due to the formation of the complex between TA macromolecules and cobalt. The highest observed adsorption amount was as high as 2778 mg g−1, significantly higher than that of the carbon prepared from carbonization of phenolic resin (205 mg g−1) and ZIF-67 (1375 mg g−1). The carbon composite material is easy to recover and reuse due to the magnetic property. The reuse experiment also showed high stability of the composite. All of the results indicated a great potential of the developed carbon composite material in wastewater treatment in the industry.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Carbon composite, Phenolic resin, ZIF-67, Tannic acid adsorption, Wastewater treatment
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-74102 (URN)10.1016/j.micromeso.2019.05.046 (DOI)000475995600002 ()2-s2.0-85067963332 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-10 (oliekm)

Available from: 2019-05-30 Created: 2019-05-30 Last updated: 2019-08-16Bibliographically 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
Wang, L., Yu, L., Zeng, C., Wang, C. & Zhang, L. (2018). Fabrication of PAA-PETPTA Janus Microspheres with Respiratory Function for Controlled Release of Guests with Different Sizes. Langmuir, 34(24), 7106-7116
Open this publication in new window or tab >>Fabrication of PAA-PETPTA Janus Microspheres with Respiratory Function for Controlled Release of Guests with Different Sizes
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2018 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 24, p. 7106-7116Article in journal (Refereed) Published
Abstract [en]

Poly(acrylic acid)–poly(ethoxylated trimethylolpropane triacrylate) (PAA–PETPTA) Janus microspheres with “respiratory” function for controlled release were prepared by polymerization of acrylic acid–ethoxylated trimethylolpropane triacrylate (AA–ETPTA) Janus microdroplets in a continuous oil phase in a simple capillary-based microfluidic device with the assistance of UV radiation. The flow rate ratios of AA and ETPTA phases and surfactant content in the continuous oil phase have a significant effect on the structure of the Janus microspheres. PAA part in the Janus microspheres has respiratory function for loading and release due to the different stimuli responses to different pHs. The hollow structure of PETPTA part with different sizes of opening serves as the host materials for PAA and could control release rate further due to the different opening sizes. The obtained PAA–PETPTA Janus microspheres showed high rhodamine B (RhB) loading of 860 mg g–1 and different controlled-release behavior in water with different pHs. The release rate increases with the increase of pH and the contact area of PAA part with water. The maximum controlled-release time for RhB was about 3 h in water with pH of 5. In addition, the Janus microspheres also showed controlled-release behavior for larger size guests, e.g., 150 nm polystyrene beads, which indicated a wide range of application. The loading and release behaviors for guests, for instance, for RhB, have almost no change even after six times of reuse, which indicated a high stability.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-69185 (URN)10.1021/acs.langmuir.8b01055 (DOI)000436022900016 ()29801415 (PubMedID)2-s2.0-85047726685 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-06-25 (andbra)

Available from: 2018-06-07 Created: 2018-06-07 Last updated: 2018-07-25Bibliographically approved
Yan, B., Zeng, C., Yu, L., Wang, C. & Zhang, L. (2018). Preparation of hollow zeolite NaA/chitosan composite microspheres via in situ hydrolysis-gelation-hydrothermal synthesis of TEOS. Microporous and Mesoporous Materials, 257, 262-271
Open this publication in new window or tab >>Preparation of hollow zeolite NaA/chitosan composite microspheres via in situ hydrolysis-gelation-hydrothermal synthesis of TEOS
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2018 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 257, p. 262-271Article in journal (Refereed) Published
Abstract [en]

In situ hydrolysis-gelation-hydrothermal (HGH) synthesis of tetraethylorthosilicate (TEOS) technique was developed to prepare hollow zeolite NaA/chitosan composite microspheres. The chitosan solution coated calcium alginate microspheres served as template to generate hollow structure, which were pre-modified by oleic acid and coated by TEOS. Furthermore, the calcium alginate microspheres were prepared by a simple homemade double T-junction mixer. During the hydrothermal process, the TEOS hydrolyzed and provided silica source for the zeolite NaA shell, meanwhile the inner calcium alginate microsphere core dissolved by the alkaline synthesis mixture and left the hollow structure. The obtained products were characterized by XRD, FT-IR, SEM, TG et al. techniques. The preparation method for calcium alginate microspheres template was simple and the preparation process had no NaA crystal seeds been involved. The hollow size could be adjusted by controlling the synthesis parameters of calcium alginate/chitosan microspheres. In addition, the functional magnetic γ-Fe2O3 nanoparticles could be introduced into the cavity during synthesis of calcium alginate/chitosan microspheres and guest magnetic γ-Fe2O3 nanoparticles had no effect on the properties of host zeolite NaA. The obtained functional magnetic hollow NaA/chitosan microspheres had decent adsorption performance for Cu2+ ions and were easy to recycle.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-65471 (URN)10.1016/j.micromeso.2017.08.053 (DOI)000418106600029 ()2-s2.0-85028697677 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-09-18 (andbra)

Available from: 2017-09-04 Created: 2017-09-04 Last updated: 2018-01-11Bibliographically 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
Yu, L., Zeng, C., Wang, C. & Zhang, L. (2017). In situ impregnation−gelation−hydrothermal crystallization synthesis of hollow fiber zeolite NaA membrane. Microporous and Mesoporous Materials, 244, 278-283
Open this publication in new window or tab >>In situ impregnation−gelation−hydrothermal crystallization synthesis of hollow fiber zeolite NaA membrane
2017 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 244, p. 278-283Article in journal (Refereed) Published
Abstract [en]

Chitosan-assisted in situ impregnation−gelation−hydrothermal (IGH) crystallization process has been developed for the preparation of hollow fiber zeolite NaA membranes. Firstly, chitosan-zeolite NaA composite hollow fibers were prepared successfully by assistance of a simple homemade tube-in-orifice spinneret. The composite hollow fibers were initially prepared by in situ impregnation–gelation–hydrothermal transformation of chitosan-silica hollow fibers in aluminate solution. Zeolite NaA membranes can be subsequently obtained on the outer surface of chitosan-zeolite NaA composite hollow fibers by in situ microwave hydrothermal treatment. The zeolite crystals in the composite hollow fibers serve as seeds for the growth of zeolite membrane. Moreover, the chitosan-silica hollow fibers were prepared by solidification of chitosan hollow fibers, which were formed in the tube-in-orifice spinneret from a chitosan-silica sol viscous aqueous solution, in the sodium hydroxide solution. Pervaporation for separation of 90 wt% ethanol aqueous solution was employed to examine the obtained membranes. The hollow fiber membranes showed high permeation flux and high stability.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-60071 (URN)10.1016/j.micromeso.2016.10.047 (DOI)000399515500034 ()2-s2.0-85028250843 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-27 (rokbeg)

Available from: 2016-11-01 Created: 2016-11-01 Last updated: 2018-07-10Bibliographically approved
Ju, M., Li, Y., Yu, L., Wang, C. & Zhang, L. (2017). Preparation of size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres. Microporous and Mesoporous Materials, 247, 75-85
Open this publication in new window or tab >>Preparation of size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres
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2017 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 247, p. 75-85Article in journal (Refereed) Published
Abstract [en]

Size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres were prepared in a simple homemade T-type mixer by polymerization of furfuryl alcohol (FA) and hydrolysis of TEOS in H2SO4 water phase microdroplets to obtain polyfurfuryl alcohol (PFA)@silica microspheres, followed by carbonization and calcination. The FA and TEOS diffuse into the water phase from an oil phase. The flow rates of oil and water phase were 4 and 2 ml h−1, respectively. It was found that the concentration of FA has a more significant effect on the diameter of carbon@silica core-shell microspheres than TEOS due to the template effect of the PFA core. However, the diameter of the hollow silica microspheres was influenced by the concentration of TEOS more significantly. The obtained core-shell microspheres and hollow silica microspheres have large surface area of 555 and 769 m2 g−1, respectively. The hollow silica microspheres have both microporous and mesoporous structure, and the percentage of mesoporous volume was as high as 89%. In addition, based on the study results, a rational formation process of the carbon@silica core-shell microsphere and hollow silica microspheres was assumed.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-62765 (URN)10.1016/j.micromeso.2017.03.058 (DOI)000402947000011 ()2-s2.0-85016573622 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-04-04 (rokbeg)

Available from: 2017-03-29 Created: 2017-03-29 Last updated: 2018-09-13Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2656-857x

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