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  • 1.
    Akhtar, Farid
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Sjöberg, Erik
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rayson, Mark
    Department of Chemistry, The University of Surrey, Guildford.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Bergström, Lennart
    Department of Materials and Environmental Chemistry, Stockholm University.
    Preparation of graded silicalite-1 substrates for all-zeolite membranes with excellent CO2/H2 separation performance2015In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 493, p. 206-211Article in journal (Refereed)
    Abstract [en]

    raded silicalite-1 substrates with a high gas permeability and low surface roughness have been produced by pulsed current processing of a thin coating of a submicron silicalite-1 powder onto a powder body of coarser silicalite-1 crystals. Thin zeolite films have been hydrothermally grown onto the graded silicalite-1 support and the all-zeolite membranes display an excellent CO2/H2 separation factor of 12 at 0 °C and a CO2 permeance of 21.3×10-7 mol m-2 s-1 Pa-1 for an equimolar CO2/H2 feed at 505 kPa and 101 kPa helium sweep gas. Thermal cracking estimates based on calculated surface energies and measured thermal expansion coefficients suggest that all-zeolite membranes with a minimal thermal expansion mismatch between the graded substrate and the zeolite film should remain crack-free during thermal cycling and the critical calcination step.

  • 2.
    Faisal, Abrar
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zarebska, Agata
    Saremi, Pardis
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Ohlin, Lindsay
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    MFI zeolite as adsorbent for selective recovery of hydrocarbons from ABE fermentation broths2014In: Adsorption, ISSN 0929-5607, E-ISSN 1572-8757, Vol. 20, no 2-3, p. 465-470Article in journal (Refereed)
    Abstract [en]

    1-Butanol and butyric acid are two interesting compounds that may be produced by acetone, butanol, and ethanol fermentation using e.g. Clostridium acetobutylicum. The main drawback, restricting the commercialization potential of this process, is the toxicity of butanol for the cell culture resulting in low concentrations of this compound in the broth. To make this process economically viable, an efficient recovery process has to be developed. In this work, a hydrophobic MFI type zeolite with high silica to alumina ratio was evaluated as adsorbent for the recovery of butanol and butyric acid from model solutions. Dual component adsorption experiments revealed that both butanol and butyric acid showed a high affinity for the hydrophobic MFI zeolite when adsorbed from aqueous model solutions. Multicomponent adsorption experiments using model solutions, mimicking real fermentation broths, revealed that the adsorbent was very selective to the target compounds. Further, the adsorption of butyric and acetic acid was found to be pH dependent with high adsorption below, and low adsorption above, the respective pKa values of the acids. Thermal desorption of butanol from MFI type zeolite was also studied and a suitable desorption temperature was identified.

  • 3.
    Hedlund, Jonas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Rayson, Mark
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Öberg, Sven
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Briddon, Patrick R.
    School of Electrical, Electronic and Computer Engineering, University of Newcastle upon Tyne.
    Mass transport in porous media from first principles: an experimental and theoretical study2012In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 415-416, p. 271-277Article in journal (Refereed)
    Abstract [en]

    In the present work, the mass transport of helium through zeolite is experimentally determined by measuring the flow of helium through a zeolite membrane. By using a mathematical model, the mass transport through defects was accounted for to arrive at mass transport through zeolite pores. For the first time, we could thereby experimentally show that the mass transport of helium in zeolite pores is strongly controlled by the amount and location of hydrocarbons in the zeolite pores and varies several orders of magnitude. The mass transport of helium in ZSM-5 zeolite pores is first reduced gradually more than one order of magnitude when the loading of n-hexane is increased from 0 to 47% of saturation. As the loading of n-hexane is further increased to 54% of saturation, the mass transport of helium in the zeolite pores is further reduced abruptly by more than two orders of magnitude. This gradual decrease followed by an abrupt decrease of mass transport is caused by adsorption of n-hexane in the zeolite pores. In a similar yet different fashion, the mass transport of helium in the zeolite pores is reduced abruptly by almost two orders of magnitude when the loading of benzene is increased from 0 to 19% of saturation due to adsorption of benzene in the pore intersections. Effective medium approximation percolation models with parameters estimated using density functional theory employing the local density approximation, i.e. models with no adjustable parameters and the most sophisticated theory yet applied to this system, can adequately describe the experimental observations.

  • 4.
    Hedlund, Jonas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Korelskiy, Danil
    Sandström, Linda
    Lindmark, Jonas
    Permporometry analysis of zeolite membranes2009In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 345, no 1-2, p. 276-287Article in journal (Refereed)
    Abstract [en]

    In permporometry analysis of zeolite membranes, the permeance of a non-adsorbing gas, such as helium, is measured as a function of pressure of a strongly adsorbing compound, such as n-hexane in the case of silicalite-1 membranes. The adsorbing compound effectively blocks the transport of the non-adsorbing gas already at very low activity of the adsorbing compound. The plot of the permeance of the non-adsorbing gas as a function of relative pressure of the adsorbing compound is denoted a permporometry pattern. The present work is based on experimental data for a number of thin MFI membranes with a film thickness ranging from 300 to 1800 nm. An adsorption-branch permporometry experiment is simple and straightforward and after activation of the membrane by removing adsorbed species at 300 °C in a flow of dry gas, a full permporometry pattern is recorded within about 7 h for such membranes. It is shown how the distribution of flow-through defects can be estimated from the permporometry pattern using a simple model for permeation based on Knudsen diffusion. The estimated defect distribution is supported by SEM observations. In addition, the permeance of the non-adsorbing gas through defects measured in permporometry can be used to predict the permeance of molecules diffusing through defects in the membrane in mixture separation experiments and also indicate the separation factor. For instance, the helium permeance through defects in an MFI membrane measured by helium/n-hexane permporometry at room temperature can be used to estimate the permeance of 2,2-dimethylbutane (DMB) in a mixture separation experiment at a higher temperature with a feed containing both DMB and n-hexane by assuming Knudsen diffusion for both helium and DMB in the defects. Also, the separation factor αn-hexane/DMB in a mixture separation experiment at a certain temperature with an MFI membrane with a given defect distribution can be estimated from n-hexane/helium permporometry data recorded at the same temperature through an empirical correlation. In summary, adsorption-branch permporometry is a very effective tool for analysis of thin zeolite membranes, that in short time gives data that can be used to estimate the distribution of flow-through defects in the membrane and to estimate the transport of large molecules through defects in separation experiments and also estimate separation performance.

  • 5.
    Karimi, Somayeh
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mortazavi, Yadollah
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Khodadadi, Abbas Ali
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Sardari, Kaymar
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Esmaeili, Mohammad
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Antzutkin, Oleg
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    High flux acetate functionalized silica membranes based on in-situ co-condensation for CO2/N2 separation2016In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 520, p. 574-582Article in journal (Refereed)
    Abstract [en]

    Acetate-functionalized silica membranes were prepared via co-condensation. The molar ratio of functional groups in the silica matrix was varied in the range of 0–0.6, denoted by x. The presence of functional groups bonded to the silica network was revealed by FTIR and 29Si and 13C solid-state NMR analysis. The stability of the groups was studied by TG analysis. The membranes were evaluated for CO2/N2 mixture separation in a temperature range of 253–373 K using a feed pressure of 9 bar and a sweep gas kept at atmospheric pressure on the permeate side. The membranes were found to be CO2-selective at all the conditions studied. The highest observed selectivity was 16 for x=0.4, with a CO2 permeance of 5.12×10−7 mol s−1 m−2 Pa−1. For x=0.2, a permeance of as high as 20.74×10−7 mol s−1 m−2 Pa−1 with a CO2/N2 selectivity of 7.5 was obtained. This permeance is the highest reported for CO2/N2 separation using functionalized silica membranes. It is proposed that the separation mechanism between CO2 and N2 was the preferential adsorption of CO2, which inhibited adsorption and permeation of N2 through the silica pore network. Permporometry results revealed that as the loading of functional groups increased, the He permeance decreased. It was also indicated that the quantity of micropores in the functionalized membrane was higher than that in the parent silica membrane.

  • 6.
    Karimi, Somayeh
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Khodadadi, Abbas Ali
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Mortazavi, Yadollah
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Esmaeili, Mohammad
    Catalysis and Nanostructured Materials Research Laboratory, College of Engineering, School of Chemical Engineering, University of Tehran.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    A simple method for blocking defects in zeolite membranes2015In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 489, p. 270-274Article in journal (Refereed)
    Abstract [en]

    The abatement of defects in zeolite membranes is essential for achieving high selectivity. In the present work, a simple and effective method for blocking defects in ultra-thin (ca. 0.5 μm) MFI zeolite membranes has been developed. The method is based on deposition of an ultra-thin (∼15 nm) layer of amorphous silica on the top surface of the membrane. Permporometry data indicated that the amount of defects, especially defects larger than 4 nm, in the membranes was significantly reduced after the modification. In mixture separation experiments, the CO2/H2 separation factor increased dramatically after blocking the defects in a defective membrane that was selected for the experiments. For instance, at 263 K and 9 bar feed pressure, the CO2/H2 separation factor increased from 8.5 to 36 after modification of the membrane, whereas the CO2 flux only decreased by ca. 40%.

  • 7.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Development of permporometry for analysis of MFI membranes2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Zeolite membranes exhibiting high flux and high selectivity are of major interest for potential future applications. In order to achieve high flux and high selectivity, the zeolite film must be thin (< 1 µm) and free from flow-through defects. The development of thin defect free zeolite membranes requires powerful tools for characterization of flow-through defects in the membranes. Permporometry is one of the most straightforward and powerful techniques for characterization of flow-through pores in ceramic membranes. In permporometry, the flow of a non-condensable gas, e.g., helium, through the membrane is monitored as a function of the activity of a strongly adsorbing compound, e.g., hydrocarbon.In the present work, MFI membranes prepared by a seeding method were characterized by permporometry using helium as the non-condensable gas and n-hexane or benzene as the adsorbing compound. In order to appreciate permporometry data, the membranes were also characterized by scanning electron microscopy (SEM), single gas permeation and separation experiments. The permporometry data were then compared to the SEM morphology of the membranes, permeances of different probe molecules and membrane separation performance.In order to determine the conditions of the permporometry experiment leading to blocking of zeolite pores, a model describing helium transport in the zeolite pores in the presence of n-hexane or benzene was developed. The model is based on percolation theory and knowledge of the adsorption isotherms and adsorption sites for n-hexane and benzene in the zeolite pores. Parameters needed in the model were estimated by Density Functional Theory (DFT) using a Local-Density Approximation (LDA), the most sophisticated theory yet applied to this system. Based on the permporometry data, it was demonstrated that the model could adequately describe helium transport in zeolite pores in the presence of the hydrocarbons.The sensitivity of the permporometry technique towards the defect size has been improved considerably. It was revealed that high quality MFI membranes prepared in the present work contained mainly micropore defects which are most like the defects in the zeolite crystal lattice (intracrystalline defects).The work has shown how permporometry data could be used to estimate the area distribution of the flow-through defects in the membranes. The results on the defect distribution were corroborated by the SEM observations and the separation experiments. The width of cracks, including support cracks, and open grain boundaries observed by SEM was in excellent agreement with the defect width estimated from permporometry data. A straightforward correlation was observed between separation data and permporometry data, i.e. membranes of higher quality according to permporometry analysis exhibited greater separation performance. Also, the permeance of molecules diffusing through defects in the membrane in the separation experiment was found to scale with the permeance of helium through the defects measured in the permporometry experiment. In addition, this work showed that single gas permeance ratios could not detect slight variations in the membrane quality. For membranes with similar however slightly different amount of defects, the ratios are mainly affected by the membrane thickness and support morphology.To summarise, the present work demonstrates that permporometry data adequately reflect membrane quality and that permporometry is a very powerful technique for MFI membrane characterization.

  • 8.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Quality and performance of zeolite membranes2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Zeolite membranes displaying high flux and high selectivity are of major interest for potential industrial applications, such as gas and liquid separations. In order to achieve high flux and high selectivity, the zeolite membrane must be thin (< 1 µm) and free from flow-through defects. The development of thin defect-free zeolite membranes requires powerful tools for characterisation of the defects in the membranes. Permporometry is one of the most straightforward, non-destructive and powerful techniques for characterisation of flow-through pores in inorganic membranes. In permporometry, the flow of a non-adsorbing gas, e.g., helium, through the membrane is monitored as a function of the activity of a strongly adsorbing compound, e.g., hydrocarbon.The work showed how permporometry can be used to quantify defects in the mesopore range in MFI membranes. The results were in excellent agreement with SEM observations and separation experiments. For the first time, it was also shown that flow-through defects down to 0.7 nm in size in MFI membranes could be detected by permporometry and quantified using the permporometry data. The total amount of defects in high quality MFI membranes was found to be small accounting for less than 1% of the total membrane area. In turn, defects with a width below 1 nm constituted as much as 97% of the total area of defects for the best membranes. The permporometry results were consistent with SEM observations and separation experiments, demonstrating that permporometry data adequately reflect membrane quality and that the technique is a very powerful and reliable characterisation tool.This work also illustrated that single gas permeance ratios could not detect slight variations in the membrane quality. For membranes with similar however slightly different amount of defects, the ratios are mainly affected by the membrane thickness and support morphology.The MFI membranes were also evaluated for separation of dilute aqueous solutions of n-butanol and ethanol, and 1 µm zeolite X membranes were evaluated for separation of water from ethanol using pervaporation. The MFI membranes were selective to n-butanol and ethanol, whereas zeolite X membranes were selective to water. The flux observed for the MFI membranes was about 100 times higher than those previously reported for n-butanol/water and about 5 times higher than the highest reported for ethanol/water separation by pervaporation. The zeolite X membranes showed good pervaporation performance in terms of both flux and selectivity. However, both flux and selectivity were found to be reduced by a significant mass transfer resistance in the support in all the pervaporation experiments. At the same time, heat transfer limitations were found to be negligible.

  • 9.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Characterization of flow-through micropores in MFI membranes by permporometry2012In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 417-418, p. 183-192Article in journal (Refereed)
    Abstract [en]

    Permporometry was used for the first time to characterize flow-through micropore defects down to 0.7 nm in size in MFI zeolite membranes. Helium was used as the non-adsorbing gas and n-hexane or benzene was used as the adsorbate. The helium flow through zeolite pores was estimated using percolation theory and the remaining flow was assigned to flow-through defects. The area distribution of flow-through defects was estimated from the data using a simple model and similar results were obtained using both adsorbates. The total area of defects determined using n-hexane as the adsorbate was as low as about 0.7% of the membrane area and defects with a width below 1 nm constituted 97% of the total defect area for the best membrane. The permporometry results were supported by n-hexane/1,3,5-trimethylbenzene separation experiments. The permporometry data were also consistent with HR-SEM observations indicating the presence of narrow open grain boundaries, and absence of large cracks and pinholes

  • 10.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhou, Ming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    A study of CO2/CO separation by sub-micron b-oriented MFI membranes2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 70, p. 65475-65482Article in journal (Refereed)
    Abstract [en]

    Separation of CO2 and CO is of great importance for many industrial applications. Today, CO2 is removed from CO mainly by adsorption or physical or chemical absorption systems that are energy-intensive and expensive. Membranes are listed among the most promising sustainable and energy-efficient alternatives for CO2 separation. Here, we study CO2/CO separation by novel sub-micron b-oriented MFI zeolite membranes in a temperature range of 258-303 K and at a feed pressure of 9 bar. Under all experimental conditions studied, the membranes were CO2-selective and displayed high CO2 permeance ranging from 17 000 to 23 000 gpu. With decreasing temperature, the CO2/CO selectivity was increasing, reaching a maximum of 26 at 258 K. We also developed a mathematical model to describe the membrane process, and it indicated that the membrane separation performance was a result of selective adsorption of CO2 on the polar zeolite. The heat of adsorption of CO2 on the zeolite is more negative due to the high quadrupole moment and polarisability of the molecule as compared to CO. At the same time, diffusional coupling (correlation effects) at high adsorbed loadings was found to favour the overall CO2/CO selectivity of the membranes by reducing the diffusivity of the lighter CO molecule in the ca. 0.55 nm pores in the zeolite. The model also indicated that the separation performance was limited by the mass transfer resistance in the support and concentration polarisation on the feed side of the membrane.

  • 11.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Leppäjärvi, Tiina
    Department of Process and Environmental Engineering, University of Oulu.
    Zhou, Han
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Tanskanen, Juha
    Department of Process and Environmental Engineering, University of Oulu.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    High flux MFI membranes for pervaporation2013In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 427, p. 381-389Article in journal (Refereed)
    Abstract [en]

    MFI membranes with a thickness of 0.5 μm prepared on a graded α-alumina support were evaluated for separation of feed mixtures of 3 wt.% n-butanol/water and 10 wt.% ethanol/water by pervaporation. The membranes were selective to n-butanol and ethanol. The flux observed in the present work was about 100 times higher than that previously reported for n-butanol/water separation by pervaporation and about 5 times higher than that for ethanol/water separation by pervaporation. At 60 °C, the observed n-butanol/water flux was about 4 kg m−2 h−1 and the n-butanol/water separation factor was about 10 for the best membrane. At the same temperature, the membrane displayed an ethanol/water flux of ca. 9 kg m−2 h−1 and an ethanol/water separation factor of ca. 5. A mathematical model indicated significant mass transfer resistance in the support, which reduced the flux and the selectivity of the membranes.

  • 12.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Characterization of small defects in MFI membranes by permporometry, separation experiments and XHR-SEM2010Conference paper (Refereed)
  • 13.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Fouladvand, Shahpar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Karimi, Somayeh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Sjöberg, Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Efficient ceramic zeolite membranes for CO2/H2 separation2015In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2015, no 3, p. 12500-12506Article in journal (Refereed)
    Abstract [en]

    Membranes are considered one of the most promising technologies for CO2 separation from industrially important gas mixtures like synthesis gas or natural gas. In order for the membrane separation process to be efficient, membranes, in addition to being cost-effective, should be durable and possess high flux and sufficient selectivity. Current CO2-selective membranes are low flux polymeric membranes with limited chemical and thermal stability. In the present work, robust and high flux ceramic MFI zeolite membranes were prepared and evaluated for separation of CO2 from H2, a process of great importance to synthesis gas processing, in a broad temperature range of 235–310 K and at an industrially relevant feed pressure of 9 bar. The observed membrane separation performance in terms both selectivity and flux was superior to that previously reported for the state-of-the-art CO2-selective zeolite and polymeric membranes. Our initial cost estimate of the membrane modules showed that the present membranes were economically viable. We also showed that the ceramic zeolite membrane separation system would be much more compact than a system relying on polymeric membranes. Our findings therefore suggest that the developed high flux ceramic zeolite membranes have great potential for selective, cost-effective and sustainable removal of CO2 from synthesis gas.

  • 14.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nabavi, Mohammad Sadegh
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Selective blocking of grain boundary defects in high-flux zeolite membranes by cokin2017In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, no 16, p. 7295-7299Article in journal (Refereed)
    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%.

  • 15.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Zhou, Han
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    An experimental study of micropore defects in MFI membranes2014In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 186, p. 194-200Article in journal (Refereed)
    Abstract [en]

    In the present work, two ultra-thin MFI membranes, prepared using hydroxide and fluoride ions as mineralizing agents, respectively, were carefully examined by permporometry. The amount of micropore defects, as determined by permporometry, differed significantly between the two different membranes. For the first time, it was demonstrated that the micropore defects determined by permporometry were most likely open grain boundaries. The results were verified by direct observation of the open grain boundaries by a state-of-the-art XHR-scanning electron microscopy instrument. In addition, the permporometry data were also consistent with permeation data using 1,3,5-trimethylbenzene (TMB) as a probe molecule, separation data using an equimolar mixture of n-hexane and TMB, and nitrogen adsorption data.

  • 16.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhou, Han
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Correction: An experimental study of micropore defects in MFI membranes2014In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 197, p. 358-Article in journal (Refereed)
    Abstract [en]

    In the present work, two ultra-thin MFI membranes, prepared using hydroxide and fluoride ions as mineralizing agents, respectively, were carefully examined by permporometry. The amount of micropore defects, as determined by permporometry, differed significantly between the two different membranes. For the first time, it was demonstrated that the micropore defects determined by permporometry were most likely open grain boundaries. The results were verified by direct observation of the open grain boundaries by a state-of-the-art XHR-scanning electron microscopy instrument. In addition, the permporometry data were also consistent with permeation data using 1,3,5-trimethylbenzene (TMB) as a probe molecule, separation data using an equimolar mixture of n-hexane and TMB, and nitrogen adsorption data

  • 17.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhou, Han
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Reprint of: An experimental study of micropore defects in MFI membranes2014In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 192, p. 69-75Article in journal (Refereed)
    Abstract [en]

    In the present work, two ultra-thin MFI membranes, prepared using hydroxide and fluoride ions as mineralizing agents, respectively, were carefully examined by permporometry. The amount of micropore defects, as determined by permporometry, differed significantly between the two different membranes. For the first time, it was demonstrated that the micropore defects determined by permporometry were most likely open grain boundaries. The results were verified by direct observation of the open grain boundaries by a state-of-the-art XHR-scanning electron microscopy instrument. In addition, the permporometry data were also consistent with permeation data using 1,3,5-trimethylbenzene (TMB) as a probe molecule, separation data using an equimolar mixture of n-hexane and TMB, and nitrogen adsorption data

  • 18.
    Korelskiy, Danil
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Zhou, Han
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    An experimental study of micropore defects in MFI membranes2013Conference paper (Refereed)
  • 19.
    Leppäjärvi, Tiina
    et al.
    Department of Process and Environmental Engineering, University of Oulu.
    Malinen, Ilkka
    Department of Process and Environmental Engineering, University of Oulu.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Tanskanen, Juha
    Oulu University.
    Maxwell-Stefan Modeling of Ethanol and Water Unary Pervaporation Through a High-silica MFI Zeolite Membrane2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 1, p. 323-332Article in journal (Refereed)
    Abstract [en]

    The pervaporative mass transfer of pure ethanol and water through a thin (0.5 mu m) supported high-silica MFI membrane was studied experimentally at 30-70 degrees C, and modeled on the basis of the Maxwell-Stefan formalism. The temperature dependency of adsorption was described with the temperature dependency of pure component saturated vapor pressure. Two scenarios of coverage dependency, i.e., coverage-dependent and coverage-independent Maxwell-Stefan diffusivity, were applied in the modeling of the mass transfer through the zeolite film. In addition, the mass-transfer resistance of the support layers was taken into account. The derived unary models provided good representations of ethanol and water pervaporation flux. The study illustrates that pure component steady-state pervaporation flux measurements at different conditions offer a feasible basis for determining diffusion coefficients. Basically, pure component adsorption isotherms and derived diffusivities can be used in the modeling of pervaporative mass transfer of mixtures using zeolite membranes

  • 20.
    Leppäjärvi, Tiina
    et al.
    Department of Process and Environmental Engineering, University of Oulu.
    Malinen, Ilkka
    Department of Process and Environmental Engineering, University of Oulu, University of Oulu.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Kangas, Jani
    University of Oulu.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Tanskanen, Juha
    Department of Process and Environmental Engineering, University of Oulu.
    Pervaporation of Ethanol/Water Mixtures through a High-silica MFI Membrane: Comparison of Different Semi-empirical Mass Transfer Models2015In: Periodica Polytechnica. Chemical Engineering, ISSN 0324-5853, Vol. 59, no 2, p. 111-123Article in journal (Refereed)
    Abstract [en]

    Pervaporation of binary ethanol/water solutions of 5-10 wt.% ethanol was studied experimentally through a thin supported high-silica MFI zeolite membrane of hydrophobic character in the temperature range of 30-70 degrees C. The fluxes obtained were very high, 2-14 kg m(-2)h(-1) with ethanol/water separation factors of 4-7. The loss of effective driving force was significant in the supporting layers, which limited the membrane performance. The correlation between the experimental data and three different semi-empirical mass-transfer models was examined The correlation was good especially when the driving force for mass-transfer was determined based solely on bulk feed, or the bulk feed and permeate conditions together Somewhat lower correlation was observed when the driving force was corrected with the effect of support resistance. This was most likely due to the inaccuracies of the used mass transfer parameters in the support. The investigated semi-empirical models can be applied for initial stage process design purposes.

  • 21. Sjöberg, Erik
    et al.
    Barnes, Simon
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    MFI membranes for separation of carbon dioxide from synthesis gas at high pressures2015In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 486, p. 132-137Article in journal (Refereed)
    Abstract [en]

    Membranes are considered to be one of the most promising technologies for simple and energy efficient removal of carbon dioxide from gas mixtures. In the present work, MFI membranes with different Si/Al ratios and counter-ions were evaluated for separation of carbon dioxide from synthesis gas, i.e. a mixture of carbon dioxide and hydrogen. Single gas permeation experiments were also carried out. These membranes consisted of a 0.5 µm thick MFI film grown on graded alumina supports. The feed pressure was varied between 3 and 8 bar and the permeate pressure was kept constant at 1 bar, while the temperature was varied in a range of 273–350 K. The silicalite-1 membrane showed the best overall carbon dioxide separation performance, in terms of flux and separation factor, when compared with NaZSM-5 and BaZSM-5 membranes. The silicalite-1 membrane displayed a CO2/H2 separation factor of 31, with a carbon dioxide flux of ca. 560 kg m−2 h−1 at 8 bar feed pressure and a temperature of 273 K. The higher performance of the silicalite-1 membrane was attributed to a more suitable CO2 adsorption isotherm, which resulted in larger difference in fractional surface loading of CO2 between the feed and permeate side for this type of membrane, and consequently higher CO2 flux and CO2/H2 separation factor. Accordingly, the difference in membrane performance was larger at low temperature (273 K), while at elevated temperatures, the CO2/H2 separation factor decreased for all membranes and the difference between the membrane types diminished, as a result of decreased carbon dioxide adsorption.

  • 22.
    Ye, Pengcheng
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Efficient Separation of N2 and He at Low Temperature Using MFI Membranes2016In: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 62, no 8, p. 2833-2842Article in journal (Refereed)
    Abstract [en]

    Ultra-thin MFI membranes were evaluated for N2/He separation over the temperature range of 85–260 K for the first time. The membranes were rather nitrogen selective at all the conditions investigated. A highest N2/He selectivity of 75.7 with a high N2 flux of 83 kg/m2/h was observed at 124 K. The separation was attributed to adsorption selectivity to N2, effectively hindering the transport of He in the zeolite pores. The exceedingly high permeance even at low temperatures was ascribed to the ultrathin (<1μm) membrane used. As the pressure ratios increased, a better separation performance was obtained. A mathematical model showed the largest difference of adsorbed loading over the film at ca. 120 K was the main reason for the observed maximum selectivity. Further, the modelling indicated the selectivity would increase 2–3 times by reducing the influence of defects, concentration polarization, and pressure drop over the support.

  • 23.
    Ye, Pengcheng
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Cryogenic air separation at low pressure using MFI membranes2015In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 487, p. 135-140Article in journal (Refereed)
    Abstract [en]

    Ultra-thin MFI membranes were for the first time evaluated for air separation at low feed pressures ranging from 100 to 1000 mbar at cryogenic temperature. The membrane separation performance at optimum temperature at all investigated feed pressures was well above the Robeson upper bound for polymeric membranes at near room temperature. The O2/N2 separation factor at optimum temperature increased as the feed pressure was decreased and reached 5.0 at 100 mbar feed pressure and a membrane temperature of 67 K. The corresponding membrane selectivity was 6.3, and the O2 permeance was as high as 8.6×10−7 mol m−2 s−1 Pa−1. This permeance was about 100 times higher than that reported for promising polymeric membranes. The membrane selectivity and high O2 permeance was most likely a result of O2/N2 adsorption selectivity. The increase in O2/N2 separation factor with decreasing pressure and temperature was probably due to increased adsorption selectivity at reduced temperature. This work has demonstrated the potential of MFI zeolite membranes for O2/N2 separations at cryogenic temperature.

  • 24.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Very High Flux MFI Membranes for Alcohol Recovery via Pervaporation at High Temperature and Pressure2015In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 153, p. 138-145Article in journal (Refereed)
    Abstract [en]

    Ultra-thin MFI membranes (0.5 μm) were evaluated for recovery of alcohols from dilute aqueous mixtures by pervaporation at high temperature and pressure for the first time. The feed pressure was sufficiently high to keep the feed in liquid state at high temperature, while the permeate pressure was kept at atmospheric and a low flow of sweep gas was used to reduce the partial pressure on the permeate side. Atmospheric pressure on the permeate side is more practical than vacuum. High feed temperature and pressure result in high fugacity in the liquid feed, which, in combination with lower permeate pressure, results in a large driving force. Consequently, the membrane exhibited very high fluxes for feeds comprised of 10 wt% ethanol/water and 5 wt% n-butanol/water mixtures at 110 °C and 140 °C, respectively. The flux observed for 10 wt% ethanol/water mixtures was as high as about 52 kg m-2 h-1, i.e., 6 times higher than the highest previously reported flux for this separation using zeolite membranes in pervaporation. For 5 wt% n-butanol/water mixtures, the flux was 40 kg m-2 h-1, which is 11 times higher than the highest previously reported flux for this separation by zeolite membranes. At these conditions, the membrane displayed separation factors for ethanol/water and n-butanol/water mixtures of 5 and 16, respectively. However, after about 6 hours of operation, the separation factor decreased significantly and the flux increased due to formation of defects in the membrane when the feed was saturated with silica. Lower membrane stability was observed for silica free feeds. The work has shown that it is possible to obtain high flux in pervporation by using ultra-thin membranes in combination with high feed temperature. The observed membrane selectivity was not excellent, due to pressure drop over the support as well as likely concentration polarization on the feed side resulting from the high flux. Membrane stability was also an issue at these conditions, however it was shown that stability could be improved by saturating the feed with silica.

  • 25.
    Zhou, Han
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Leppäjärvi, Tiina
    Department of Process and Environmental Engineering, University of Oulu.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Tanskanen, Juha
    Department of Process and Environmental Engineering, University of Oulu.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Ultrathin zeolite X membranes for pervaporation dehydration of ethanol2012In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 399–400, p. 106-111Article in journal (Refereed)
    Abstract [en]

    Discrete Faujasite zeolite nanocrystals with an average size of about 60 nm were attached as a well-defined monolayer on the surface of porous graded alumina supports. Ultrathin zeolite X films with a total thickness of about 1 μm were grown from the seed monolayers by hydrothermal treatment in clear synthesis solutions. One of the membranes showed a total flux of 3.37 ± 0.08 kg m -2 h -1 and a separation factor of 296 ± 4 for dehydration of a 90/10 wt.% ethanol/water mixture by pervaporation at 65 °C. Moreover, the membranes displayed stable performance during pervaporation for 5.5 h operation. A mathematical model indicated that the flux and selectivity of the membranes were limited by pressure drop in the supports. Therefore, in order to obtain higher flux, the permeability of the support must be improved.

  • 26.
    Zhou, Han
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Sjöberg, Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Ultra-thin hydrophobic MFI membranes2013Conference paper (Refereed)
  • 27.
    Zhou, Han
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Sjöberg, Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Ultrathin Hydrophobic MFI Membranes2014In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 192, p. 76-81Article in journal (Refereed)
    Abstract [en]

    Hydrophobic MFI membranes with a film thickness of less than 500 nm and a very low amount of defects were grown on α-alumina supports in fluoride media at near neutral pH (denoted TPAF-MFI membrane). These membranes are at least 4 times thinner than previous membranes prepared in fluoride media at near neutral pH; moreover, corresponding separation performance is the first time reported in this paper. For comparison, MFI membranes with a film thickness of about 500 nm were grown in hydroxide media at high pH (denoted TPAOH-MFI membrane). According to the permporometry results, the amount of defects in the TPAF-MFI membranes is about half of that in the TPAOH-MFI membranes, and most of the defects in both membranes are smaller than 1 nm. The membranes were evaluated for separation of a feed of 5 kPa n-butanol and 5kPa water, with 91 kPa helium as balance gas and 101 kPa helium as sweep gas. Both membranes displayed high permeance and the TPAF-MFI membrane was more selective to n-butanol than the TPAOH-MFI membrane. Interestingly, the total permeance and n-butanol/water separation factor increased to 11×10-7 mol/(m2 s Pa) and 19, respectively, after activation of the TPAF-MFI membrane at 300 ˚C in a helium flow saturated with n-butanol at 25 ˚C. The TPAF-MFI membrane also displayed a CO2/H2 separation factor of 6 at 25˚C and a CO2 permeance of 26×10-7 mol/(m2 s Pa) for a feed of 450 kPa CO2 and 450 kPa H2 and 101 kPa helium sweep gas.

  • 28.
    Zhou, Ming
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    A Uniformly Oriented MFI Membrane for Improved CO2 Separation2014In: Angewandte Chemie, ISSN 0044-8249, Vol. 126, no 13, p. 3560-3563Article in journal (Refereed)
    Abstract [en]

    Membrane separation of CO2 from natural gas, biogas, synthesis gas, and flu gas is a simple and energy-efficient alternative to other separation techniques. But results for CO2-selective permeance have always been achieved by randomly oriented and thick zeolite membranes. Thin, oriented membranes have great potential to realize high-flux and high-selectivity separation of mixtures at low energy cost. We now report a facile method for preparing silica MFI membranes in fluoride media on a graded alumina support. In the resulting membrane straight channels are uniformly vertically aligned and the membrane has a thickness of 0.5 μm. The membrane showed a separation selectivity of 109 for CO2/H2 mixtures and a CO2 permeance of 51×10−7 mol m−2 s−1 Pa−1 at −35 °C, making it promising for practical CO2 separation from mixtures

  • 29.
    Zhou, Ming
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ye, Pengcheng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    A Uniformly Oriented MFI Membrane for Improved CO2 Separation2014In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 53, no 13, p. 3492-3495Article in journal (Refereed)
    Abstract [en]

    Membrane separation of CO2 from natural gas, biogas, synthesis gas, and flu gas is a simple and energy-efficient alternative to other separation techniques. But results for CO2-selective permeance have always been achieved by randomly oriented and thick zeolite membranes. Thin, oriented membranes have great potential to realize high-flux and high-selectivity separation of mixtures at low energy cost. We now report a facile method for preparing silica MFI membranes in fluoride media on a graded alumina support. In the resulting membrane straight channels are uniformly vertically aligned and the membrane has a thickness of 0.5m. The membrane showed a separation selectivity of 109 for CO2/H-2 mixtures and a CO2 permeance of 51x10(-7)molm(-2)s(-1)Pa(-1) at -35 degrees C, making it promising for practical CO2 separation from mixtures

1 - 29 of 29
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