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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
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
Mu, L., Wu, J., Matsakas, L., Chen, M., Vahidi, A., Grahn, M., . . . Shi, Y. (2018). Lignin from Hardwood and Softwood Biomass as a Lubricating Additive to Ethylene Glycol. Molecules, 23(3), Article ID 537.
Open this publication in new window or tab >>Lignin from Hardwood and Softwood Biomass as a Lubricating Additive to Ethylene Glycol
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2018 (English)In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 23, no 3, article id 537Article in journal (Refereed) Published
Abstract [en]

Ethylene glycol (EG)-based lubricant was prepared with dissolved organosolv lignin from birch wood (BL) and softwood (SL) biomass. The effects of different lignin types on the rheological, thermal, and tribological properties of the lignin/EG lubricants were comprehensively investigated by various characterization techniques. Dissolving organosolv lignin in EG results in outstanding lubricating properties. Specifically, the wear volume of the disc by EG-44BL is only 8.9% of that lubricated by pure EG. The enhanced anti-wear property of the EG/lignin system could be attributed to the formation of a robust lubrication film and the strong adhesion of the lubricant on the contacting metal surface due to the presence of a dense hydrogen bonding (H-bonding) network. The lubricating performance of EG-BL outperforms EG-SL, which could be attributed to the denser H-bonding sites in BL and its broader molecular weight distribution. The disc wear loss of EG-44BL is only 45.7% of that lubricated by EG-44SL. Overall, H-bonding is the major contributor to the different tribological properties of BL and SL in EG-based lubricants.

Place, publisher, year, edition, pages
MDPI, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Bioprocess Technology Chemical Process Engineering
Research subject
Machine Elements; Biochemical Process Engineering; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-67800 (URN)10.3390/molecules23030537 (DOI)000428514100028 ()29495559 (PubMedID)2-s2.0-85043353975 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-03-01 (andbra)

Available from: 2018-03-01 Created: 2018-03-01 Last updated: 2019-04-02Bibliographically 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
Nyberg, E., Grahn, M. & Minami, I. (2017). Additives to Improve Tribological Properties of Ionic Liquid as Base Fluids. In: : . Paper presented at 72nd STLE Annual Meeting & Exhibition, Atlanta, GA, May 21-25 2017. Atlanta, GA
Open this publication in new window or tab >>Additives to Improve Tribological Properties of Ionic Liquid as Base Fluids
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Room temperature ionic liquids (RTILs) have several properties which make them interesting candidates as base fluids for extreme conditions. However, a lack of compatibility with tribo-improving additives combined with an often overly aggressive nature is limiting their use as base fluids. To overcome these drawbacks, hydrocarbon-imitating RTIL base fluids have recently been developed. These lubricants aim for a more balanced interaction with metal surfaces while enabling compatibility with common additives, so that the reactivity with the lubricated surface can be tuned in a manner similar to hydrocarbon base oil–additive systems. In this work, the effects of several common additives in the novel RTIL were examined by laboratory tribotesting. Surface analysis was performed in order to study the lubrication mechanisms.

Place, publisher, year, edition, pages
Atlanta, GA: , 2017
Keywords
Tribology, ionic liquids, friction, wear, performance additive
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Chemical Process Engineering
Research subject
Machine Elements; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-70341 (URN)
Conference
72nd STLE Annual Meeting & Exhibition, Atlanta, GA, May 21-25 2017
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-08-14Bibliographically approved
Farzaneh, A., DeJaco, R. F., Ohlin, L., Holmgren, A., Siepmann, J. I. & Grahn, M. (2017). Comparative Study of the Effect of Defects on Selective Adsorption of Butanol from Butanol/Water Binary Vapor Mixtures in Silicalite-1 Films. Langmuir, 33(34), 8420-8427
Open this publication in new window or tab >>Comparative Study of the Effect of Defects on Selective Adsorption of Butanol from Butanol/Water Binary Vapor Mixtures in Silicalite-1 Films
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2017 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 34, p. 8420-8427Article in journal (Refereed) Published
Abstract [en]

A promising route for sustainable 1-butanol (butanol) production is ABE (acetone, butanol, ethanol) fermentation. However, recovery of the products is challenging because of the low concentrations obtained in the aqueous solution, thus hampering large-scale production of biobutanol. Membrane and adsorbent-based technologies using hydrophobic zeolites are interesting alternatives to traditional separation techniques (e.g., distillation) for energy-efficient separation of butanol from aqueous mixtures. To maximize the butanol over water selectivity of the material, it is important to reduce the number of hydrophilic adsorption sites. This can, for instance, be achieved by reducing the density of lattice defect sites where polar silanol groups are found. The density of silanol defects can be reduced by preparing the zeolite at neutral pH instead of using traditional synthesis solutions with high pH. In this work, binary adsorption of butanol and water in two silicalite-1 films was studied using in situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy under equal experimental conditions. One of the films was prepared in fluoride medium, whereas the other one was prepared at high pH using traditional synthesis conditions. The amounts of water and butanol adsorbed from binary vapor mixtures of varying composition were determined at 35 and 50 °C, and the corresponding adsorption selectivities were also obtained. Both samples showed very high selectivities (100-23 000) toward butanol under the conditions studied. The sample having low density of defects, in general, showed ca. a factor 10 times higher butanol selectivity than the sample having a higher density of defects at the same experimental conditions. This difference was due to a much lower adsorption of water in the sample with low density of internal defects. Analysis of molecular simulation trajectories provides insights on the local selectivities in the zeolite channel network and at the film surface.

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-65148 (URN)10.1021/acs.langmuir.7b02097 (DOI)000409292500008 ()28767246 (PubMedID)2-s2.0-85028620796 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-09-05 (rokbeg)

Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-07-10Bibliographically 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
Nyberg, E., Mouzon, J., Grahn, M. & Minami, I. (2017). Formation of Boundary Film from Ionic Liquids Enhanced by Additives. Applied Sciences, 7(5), Article ID 433.
Open this publication in new window or tab >>Formation of Boundary Film from Ionic Liquids Enhanced by Additives
2017 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 7, no 5, article id 433Article in journal (Refereed) Published
Abstract [en]

Room temperature ionic liquids (RTILs) have several properties that make them interesting candidates as base fluids for extreme conditions. However, a lack of compatibility with tribo-improving additives combined with an often overly aggressive nature is limiting their use as base fluids. To overcome these drawbacks, hydrocarbon-imitating RTIL base fluids have recently been developed. In this study, the effects of several common additives in the novel RTIL (P-SiSO) were examined by laboratory tribotesting. A reciprocating steel-steel ball-on-flat setup in an air atmosphere was used, where the lubricant performance was evaluated over a range of loads and temperatures. Surface analyses after testing were carried out using optical profilometry, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Neat P-SiSO displayed high performance in the tribotests. At an elevated load and temperature, a shift in lubrication mode was observed with an accompanying increase in friction and wear. Surface analysis revealed a boundary film rich in Si and O in the primary lubrication mode, while P was detected after a shift to the secondary lubrication mode. An amine additive was effective in reducing wear and friction under harsh conditions. The amine was determined to increase formation of the protective Si–O film, presumably by enhancing the anion activity.

Place, publisher, year, edition, pages
Basel: MDPI, 2017
Keywords
gränsskiktssmörjning, jonvätska, friktion, nötning, tribologi
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Chemical Process Engineering
Research subject
Machine Elements; Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-63211 (URN)10.3390/app7050433 (DOI)000404449000002 ()2-s2.0-85018920929 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-05-10 (rokbeg)

Available from: 2017-05-02 Created: 2017-05-02 Last updated: 2018-11-26Bibliographically 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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ORCID iD: ORCID iD iconorcid.org/0000-0002-4755-5754

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