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Hua, J., Björling, M., Grahn, M., Larsson, R. & Shi, Y. (2019). A smart friction control strategy enabled by CO2 absorption and desorption. Scientific Reports, 9(1), Article ID 13262.
Open this publication in new window or tab >>A smart friction control strategy enabled by CO2 absorption and desorption
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 13262Article in journal (Refereed) Published
Abstract [en]

Intelligent control of friction is an attractive but challenging topic and it has rarely been investigated for full size engineering applications. In this work, it is instigated if it would be possible to adjust friction by controlling viscosity in a lubricated contact. By exploiting the ability to adjust the viscosity of the switchable ionic liquids, 1,8-Diazabicyclo (5.4.0) undec-7-ene (DBU)/ glycerol mixture via the addition of CO2, the friction could be controlled in the elastohydrodynamic lubrication (EHL) regime. The friction decreased with increasing the amount of CO2 to the lubricant and increased after partial releasing CO2. As CO2 was absorbed by the liquid, the viscosity of the liquid increased which resulted in that the film thickness increased. At the same time the pressure-viscosity coefficient decreased with the addition of CO2. When CO2 was released again the friction increased and it was thus possible to control friction by adding or removing CO2.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Chemical Process Engineering Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Chemical Technology; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-76046 (URN)10.1038/s41598-019-49864-w (DOI)000485680900059 ()31519987 (PubMedID)2-s2.0-85072208170 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-09-18 (johcin)

Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2019-10-25Bibliographically 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
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
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ORCID iD: ORCID iD iconorcid.org/0000-0002-4755-5754

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