Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Adsorption Properties of MFI-Type Zeolite Films for Upgrading of Biofuels
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering. (Chemical Technology)
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

With the depleting reservoirs of fossil fuels, increasing environmental concerns for flue-gas emissions from fossil-fuel combustion and growing world population, the need for the development of new sustainable fuels is higher than ever. However, to be able to compete with today’s mature technologies for production of fuels from fossil sources, new efficient processing alternatives for upgrading of biofuels must be developed.

   Bio-fuels produced by e.g. fermentative processes are promising alternatives to traditional chemicals and fuels produced from fossil sources. Recovery of biofuels by selective membranes and adsorbents has been identified as promising energy efficient recovery routes.

In this work, adsorption properties of MFI-type zeolite films were studied using in situ ATR-FTIR spectroscopy in order to understand the adsorption properties of these zeolites.

   Single component adsorption isotherms of butanol and water vapor were determined at different temperatures using ATR-FTIR spectroscopy. The Langmuir and Sips model were successfully fitted to experimental data, and the fitted parameters obtained in this work were in very good agreement with values reported in the literature. Adsorbed amounts of butanol and water from binary vapor mixtures were extracted from the infrared spectra as well as the adsorption selectivities. The silicalite-1 film prepared in fluoride medium found to be significantly more butanol selective due to the exceptionally low density of defects in the structure.

   Biogas (methane) is another promising biofuel that is commonly produced by anaerobic degradation of biomass. However, before it may be used, contaminants have to be removed from the gas; two of the most abundant contaminants in biogas are carbon dioxide and water vapor. Adsorption of a ternary mixture of methane, carbon dioxide and water vapor in zeolite Na-ZSM-5 has been studied at various compositions and temperatures using ATR–FTIR spectroscopy. The amount adsorbed determined from experimental data were compared to predictions by the Ideal Adsorbed Solution Theory (IAST). This result confirms that Na-ZSM-5 could be a promising membrane material for upgrading of biogas.

Place, publisher, year, edition, pages
Lluleå: Luleå University of Technology, 2016.
National Category
Engineering and Technology Chemical Engineering
Research subject
Chemical Technology
Identifiers
URN: urn:nbn:se:ltu:diva-60958ISBN: 978-91-7583-781-9 (print)ISBN: 978-91-7583-782-6 (electronic)OAI: oai:DiVA.org:ltu-60958DiVA: diva2:1052600
Public defence
2017-02-20, C305, Luleå tekniska universitet, 10:00
Opponent
Supervisors
Available from: 2016-12-09 Created: 2016-12-07 Last updated: 2017-10-19Bibliographically approved
List of papers
1. Adsorption of Butanol and Water Vapors in Silicalite‑1 Films with a Low Defect Density
Open this publication in new window or tab >>Adsorption of Butanol and Water Vapors in Silicalite‑1 Films with a Low Defect Density
Show others...
2016 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, 11789-11798 p.Article in journal (Refereed) Published
Abstract [en]

Pure silica zeolites are potentially hydrophobic and have therefore been considered to be interesting candidates for separating alcohols, e.g., 1-butanol, from water. Zeolites are traditionally synthesized at high pH, leading to the formation of intracrystalline defects in the form of silanol defects in the framework. These silanol groups introduce polar adsorption sites into the framework, potentially reducing the adsorption selectivity toward alcohols in alcohol/water mixtures. In contrast, zeolites prepared at neutral pH using the fluoride route contain significantly fewer defects. Such crystals should show a much higher butanol/water selectivity than crystals prepared in traditional hydroxide (OH−) media. Moreover, silanol groups are present at the external surface of the zeolite crystals; therefore, minimizing the external surface of the studied adsorbent is important. In this work, we determine adsorption isotherms of 1-butanol and water in silicalite-1 films prepared in a fluoride (F−) medium using in situ attenuated total reflectance−Fourier transform infrared (ATR−FTIR) spectroscopy. This film was composed of well intergrown, plate-shaped b-oriented crystals, resulting in a low external area. Single-component adsorption isotherms of 1-butanol and water were determined in the temperature range of 35− 80 °C. The 1-butanol isotherms were typical for an adsorbate showing a high affinity for a microporous material and a large increase in the amount adsorbed at low partial pressures of 1-butanol. The Langmuir−Freundlich model was successfully fitted to the 1-butanol isotherms, and the heat of adsorption was determined. Water showed a very low affinity for the adsorbent, and the amounts adsorbed were very similar to previous reports for large silicalite-1 crystals prepared in a fluoride medium. The sample also adsorbed much less water than did a reference silicalite-1(OH−) film containing a high density of internal defects.The results show that silicalite-1 films prepared in a F− medium with a low density of defects and external area are very promising for the selective recovery of 1-butanol from aqueous solutions.

National Category
Other Chemical Engineering Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-60688 (URN)10.1021/acs.langmuir.6b03326 (DOI)000388156000009 ()2-s2.0-84995812342 (Scopus ID)
Note

Validerad; 2016; Nivå 2; 2016-12-02 (andbra)

Available from: 2016-11-25 Created: 2016-11-25 Last updated: 2017-10-19Bibliographically approved
2. Adsorption of Water and Butanol in Silicalite-1 Film Studied with in-situ ATR-FTIR Spectroscopy
Open this publication in new window or tab >>Adsorption of Water and Butanol in Silicalite-1 Film Studied with in-situ ATR-FTIR Spectroscopy
Show others...
2015 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, no 17, 4887-4894 p.Article in journal (Refereed) Published
Abstract [en]

Biobutanol produced by, e.g., acetone–butanol–ethanol (ABE) fermentation is a promising alternative to petroleum-based chemicals as, e.g., solvent and fuel. Recovery of butanol from dilute fermentation broths by hydrophobic membranes and adsorbents has been identified as a promising route. In this work, the adsorption of water and butanol vapor in a silicalite-1 film was studied using in situ attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy to better understand the adsorption properties of silicalite-1 membranes and adsorbents. Single-component adsorption isotherms were determined in the temperature range of 35–120 °C, and the Langmuir model was successfully fitted to the experimental data. The adsorption of butanol is very favorable compared to that of water. When the silicalite-1 film was exposed to a butanol/water vapor mixture with 15 mol % butanol (which is the vapor composition of an aqueous solution containing 2 wt % butanol, a typical concentration in an ABE fermentation broth, i.e., the composition of the gas obtained from gas stripping of an ABE broth) at 35 °C, the adsorption selectivity toward butanol was as high as 107. These results confirm that silicalite-1 quite selectively adsorbs hydrocarbons from vapor mixtures. To the best of our knowledge, this is the first comprehensive study on the adsorption of water and butanol in silicalite-1 from vapor phase.

Abstract [sv]

Bio-butanol produced by e.g. acetone–butanol–ethanol (ABE) fermentation is a promising alternative to petroleum-based chemicals as e.g. solvent and fuel. Recovery of butanol from dilute fermentation broths by hydrophobic membranes and adsorbents has been identified as a promising route. In this work, the adsorption of water and butanol vapor in a silicalite-1 film was studied using in-situ ATR-FTIR spectroscopy in order to better understand the adsorption properties of silicalite-1 membranes and adsorbents. Single component adsorption isotherms were determined in the temperature range of 35-120°C and the Langmuir model was successfully fitted to the experimental data. The adsorption of butanol is very favorable compared to that of water. When the silicalite-1 film was exposed to a butanol/water vapor mixture with 15 mol% of butanol (which is the vapor composition of an aqueous solution containing 2 wt% of butanol, a typical concentration in an ABE fermentation broth, i.e. the composition of the gas obtained from gas stripping of an ABE broth) at 35 °C, the adsorption selectivity towards butanol was as high as 107. These results confirm that silicalite-1 quite selectively adsorbs hydrocarbons from vapor mixtures.

National Category
Chemical Process Engineering
Research subject
Chemical Technology
Identifiers
urn:nbn:se:ltu:diva-11363 (URN)10.1021/acs.langmuir.5b00489 (DOI)a506afed-96a6-4841-b99b-143794fb680d (Local ID)a506afed-96a6-4841-b99b-143794fb680d (Archive number)a506afed-96a6-4841-b99b-143794fb680d (OAI)
Note
Validerad; 2015; Nivå 2; 20150420 (magr)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-10-19Bibliographically approved
3. Colloidal Defect-Free Silicalite-1 Single Crystals: Preparation, Structure Characterization, Adsorption, and Separation Properties for Alcohol/Water Mixtures
Open this publication in new window or tab >>Colloidal Defect-Free Silicalite-1 Single Crystals: Preparation, Structure Characterization, Adsorption, and Separation Properties for Alcohol/Water Mixtures
Show others...
2015 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, no 30, 8488-8494 p.Article in journal (Refereed) Published
Abstract [en]

In this work, colloidal silicalite-1 single crystals are for the first time synthesized using fluoride as mineralizing agent at near neutral pH. SEM, TEM, DLS, XRD, solid-state 29Si MAS NMR, and adsorption/desorption experiments using nitrogen, water, n-butanol, and ethanol as adsorbates were used to characterize the crystals. The single crystals have a platelike habit with a length of less than 170 nm and an aspect ratio (length/width) of about 1.2, and the thickness of the crystals is less than 40 nm. Compared with silicalite-1 crystals grown using hydroxide as mineralizing agent, the amount of structural defects in the lattice is significantly reduced and the hydrophobicity is increased. Membrane separation and adsorption results show that the synthesized defect-free crystals present high selectivity to alcohols from alcohol/water mixtures. The n-butanol/water adsorption selectivities were ca. 165 and 14 for the defect-free crystals and a reference sample containing defects, respectively, illustrating the improvement in n-butanol/water selectivity by eliminating the polar silanol defects.

National Category
Chemical Process Engineering Physical Chemistry
Research subject
Chemical Technology; Chemistry of Interfaces
Identifiers
urn:nbn:se:ltu:diva-7846 (URN)10.1021/acs.langmuir.5b02520 (DOI)64403f34-d43d-43de-9d6f-b5e17b81fbdc (Local ID)64403f34-d43d-43de-9d6f-b5e17b81fbdc (Archive number)64403f34-d43d-43de-9d6f-b5e17b81fbdc (OAI)
Note
Validerad; 2015; Nivå 2; 20150725 (magr)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-10-19Bibliographically approved

Open Access in DiVA

fulltext(9563 kB)161 downloads
File information
File name FULLTEXT01.pdfFile size 9563 kBChecksum SHA-512
8e24b1bb14d3d998e0fe712f45d7eac77861f5767807f8414f53b536b8bc59b238e7f12856d7bdad16170171c0a9a927aebe0ee621c98a0f296d492317bde237
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Farzaneh, Amirfarrokh
By organisation
Department of Civil, Environmental and Natural Resources Engineering
Engineering and TechnologyChemical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 161 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 193 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf