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  • 1.
    Cai, Juanjaun
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Jiang, Leilei
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Wei, Huaming
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Preparation of carbon/cobalt composite from phenolic resin and ZIF-67 for efficient tannic acid adsorption2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 287, p. 9-17Article in journal (Refereed)
    Abstract [en]

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

  • 2.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Maennlein, Alexis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Yu, Liang
    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.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Mechanical & Industrial Engineering (MIE), University of Toronto, Toronto, ON, M5S 3G8, Canada.
    Monolithic carbon aerogels from bioresources and their application for CO2 adsorption2021In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 323, article id 111236Article in journal (Refereed)
    Abstract [en]

    Monolithic binder-free CO2 adsorbents with high adsorption capacity, selectivity, adsorption-desorption kinetics, and regenerability are highly desired to both reduce the environmental impact of anthropogenic CO2 emissions and purify valuable gases from CO2. Herein, we report a strategy to prepare monolithic carbonaceous CO2 adsorbents from low-cost and underutilized bioresources, which enabled the formation of a delicate anisotropic, hierarchical porous structure. With optimized material composition and processing conditions, the biobased carbon adsorbent demonstrated a CO2 adsorption capacity of 4.49 mmol g-1 at 298 K and 100 kPa, relatively weak adsorbent-adsorbate affinity, good CO2/N2 selectivity, and advantageous hydrophobicity against water vapor. Moreover, the unique anisotropic porous structure provided high stiffness and good flexibility to the adsorbent in the axial and radial directions, respectively. We confirmed that this type of carbon adsorbent could be packed in a column for dynamic CO2 capture independent of any binders, indicating its promising future for further development toward widespread utilization.

  • 3.
    Gong, Jie
    et al.
    College of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou, 213001, Jiangsu, PR China.
    Tong, Fei
    College of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou, 213001, Jiangsu, PR China.
    Zhang, Chunyong
    College of Chemical and Environmental Engineering, Jiangsu University of Technology, Changzhou, 213001, Jiangsu, PR China.
    Nobandegani, Mojtaba Sinaei
    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.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Bacterial cellulose assisted synthesis of hierarchical pompon-like SAPO-34 for CO2 adsorption2022In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 331, article id 111664Article in journal (Refereed)
    Abstract [en]

    In the present work, a biosynthesis route for the preparation of hierarchical pompon-like SAPO-34 was developed. Commercially available bacterial cellulose aerogel was used as template. SiO2 loaded bacterial cellulose aerogel was used as silica source and a simple hydrothermal treatment was used for crystallization. XRD, FT-IR, SEM, TEM, N2 adsorption-desorption and TG techniques were employed to characterize the obtained samples. The hierarchical pompon-like SAPO-34 showed a spherical morphology that was comprised of nanosheets with a thickness less than 30 nm. The specific surface area of the hierarchical pompon-like SAPO-34 was 498 m2/g that was higher than the trigonal SAPO-34 crystals of 465 m2/g. The ultrasonic treatment experiment indicated a high stability of the pompon-like structure. In addition, the hierarchical pompon-like SAPO-34 exhibited a CO2 adsorption capacity of 2.26 mmol/g at 100 kPa and 298K and the corresponding CO2/CH4 ideal separation factor was 5.7, which was higher than that of trigonal SAPO-34 crystals. The saturated adsorption capacity and b-value were estimated using single site Langmuir, Toth and Sips adsorption isotherm models and the observed results were constant. Compared with trigonal SAPO-34, hierarchical pompon-like SAPO-34 displayed a higher saturated adsorption capacity, but a lower b-value.

  • 4.
    Hedlund, Jonas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba Sinaei
    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.
    The origin of the surface barrier in nanoporous materials2022In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 641, article id 119893Article in journal (Refereed)
    Abstract [en]

    Surface barriers are influencing the mass transfer in nanopores, but their origin is unclear and can be quite different in different materials. For MFI and CHA membranes studied here, we show that the surface barrier may be a surface diffusion process with higher activation energy than the surface diffusion process in the pores, but other possible mechanisms such as pore blocking and pore narrowing has not been ruled out. The higher activation energy is probably a result of less interaction between adsorbed molecules at the pore mouth than inside the pores, i.e. the barrier is simply a geometrical effect in these materials. For pure components at low concentration in MFI zeolite, we found that barrier is proportional to the product of the molecular weight and heat of desorption. For MFI and CHA zeolite, we observed that the barrier is a function of concentration and approach zero at high concentration and that the barriers of the components become more similar due to interaction between the components in mixtures, which explains the high and selective mass transfer displayed by these nanoporous materials at high concentration.

  • 5.
    Hedlund, Jonas
    et al.
    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.
    Nobandegani, Mojtaba Sinaei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Diffusion of small molecules in ultra-thin MFI membranes2019Conference paper (Other academic)
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  • 6.
    Ju, Minhua
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University.
    Li, Yupeng
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Preparation of size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres2017In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 247, p. 75-85Article in journal (Refereed)
    Abstract [en]

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

  • 7.
    Ju, Minhua
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University , P. R. China.
    Li, Yupeng
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University , P. R. China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University , P. R. China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University , P. R. China.
    Two-Phase Diffusion Technique for the Preparation of Ultramacroporous/Mesoporous Silica Microspheres via Interface Hydrolysis, Diffusion, and Gelation of TEOS2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 5, p. 2046-2056Article in journal (Refereed)
    Abstract [en]

    Honeycombed hierarchical ultramacroporous/mesoporous silica microspheres were prepared via the hydrolysis of TEOS in the oil-water interface, with subsequent diffusion and gelation in the acidic water-phase microdroplets with the assistance of a simple homemade microdevice. The diffusion of furfuryl alcohol (FA) also happened at a relatively high rate during the hydrolysis and diffusion of TEOS. Therefore, plenty of FA will be inside of the water microdroplets and form a decent number of polyfurfuryl alcohol (PFA) microparticles, thereby obtaining honeycombed hierarchical porosity silica microspheres with abundant ultramacroporous cavities and mesopores after calcination. It was found that the concentration of FA, residence time, and reaction temperature have significant effects on the porosity and pore size due to the influence on the diffusion rate and amount of FA in water-phase microdroplets. The honeycombed silica microspheres have obvious microscopic visible ultramacroporous cavities with the submicrometer cavity diameter as high as 85% porosity based on the rough overall volume of microsphere. N2 adsorption-desorption isotherms show that the honeycombed hierarchical porosity silica microspheres have a high surface area of 602 m2 g-1, a mesopore volume of 0.77 cm3/g, and a mesopore porosity of 99.6% based on the total pore volume of N2 adsorption-desorption. On the basis of the experiment results, a rational formation process of the honeycombed hierarchical porosity silica microspheres was deduced.

  • 8.
    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%.

  • 9.
    Li, Jie
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing, PR China.
    Jiang, Leilei
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing, PR China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing, PR China.
    Preparation of Silica@Silica Core–Shell Microspheres Using an Aqueous Two-Phase System in a Novel Microchannel Device2020In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 36, no 2, p. 576-584Article in journal (Refereed)
    Abstract [en]

    In the present work, a novel microchannel device was developed and used for the preparation of core–shell microspheres combining with a dextran/poly(ethylene glycol) diacrylate (DEX/PEGDA) aqueous two-phase system. Silica@silica core–shell microspheres were prepared as a model material. Silica@silica core–shell microspheres with different sizes of cores and thicknesses of shells were prepared by using different flowrate ratios of DEX/silica and PEGDA/silica aqueous solutions. The content of colloidal silica and the calcination temperature have a significant effect on the texture properties of the prepared core–shell microspheres. The surface area decreased from 199 to 177 m2/g with an increase in the colloidal silica content from 30 to 60 wt %. For a specific colloidal silica content (50 wt %), with the increase in calcination temperature from room temperature to 650 °C, the total pore volume went through a maximum of 0.7 cm3 g–1 with a surface area of 178 m2 g–1 and pore size of 7.32 nm at 450 °C. Due to the accumulation of metal nanoparticles in DEX, different metal nanoparticles (Ni and Pd) were successfully introduced into the core of the core–shell microspheres for the preparation of silica/metal nanoparticles@silica core–shell microsphere catalysts. The catalysts showed similar catalytic performance as the metal nanoparticles for hydrogenation of 4-nitrophenol with a conversion higher than 95%. However, the core–shell microsphere catalyst is much easier to recover. The reuse experiments indicated that the core–shell catalyst has high stability.

  • 10.
    Li, Jie
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    Xu, Zhenheng
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    Preparation of hundred-micron carbon spheres using solvent extraction in a simple microchannel device2022In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 343, article id 112186Article in journal (Refereed)
    Abstract [en]

    Carbon microspheres with a uniform size of about 170 μm were prepared in a simple co-flow microfluidic device using solvent extraction method. An ethanol solution of colloidal silica and phenol formaldehyde (PF) resol was used as the dispersion phase, and a mixture of hexane and diisopropylamine was used as the continuous phase. The droplets of PF resol resin/silica were generated in the continuous phase. Colloidal silica assisted the formation of the spherical structure and worked as a pore generator. The continuous phase was also used as extractant and catalyst for PF resin/silica microspheres formation. Curing, drying, carbonization and leaching were used for the post-treatment of the PF resin/silica microspheres to obtain porous carbon microspheres. The carbon microspheres displayed a narrow size distribution and a high surface area of 679 m2/g coupled with adjustable mesopores and large mesopore volume. Carbon microspheres prepared from the dispersion phase with different PF/silica ratios (denoted as carbon/silica (C/Si) ratios) were studied and the formation mechanism of the PF/silica microspheres was deeply explored.

  • 11.
    Li, Kang
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Cai, Juanjuan
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211816, China.
    C@TiO2 core-shell adsorbents for efficient rhodamine B adsorption from aqueous solution2021In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 320, article id 111110Article in journal (Refereed)
    Abstract [en]

    In the present work, C@TiO2 core-shell adsorbents were successfully prepared and the adsorption capacities for rhodamine B (RB) were investigated at different conditions. The adsorbents were prepared by first in-situ hydrolysis and deposition of TBOT on the surface of ZIF-8 nanoparticles to obtain ZIF-8@titania gel, and then carbonization. XRD, SEM, TEM, and N2 adsorption-desorption techniques were employed to characterize the adsorbents. The results showed that the adsorbents were comprised of TiO2 shell and carbon core. Large surface area and hierarchical pores, which were different from ZIF-8 derived porous carbon, were generated due to the less contraction of carbon during carbonization when robust TiO2 shell covered on the surface. The highest adsorption capacity for RB was 298 mg/g on C@TiO2. Apart from the hierarchical pores and large surface area, the low surface charge of C@TiO2 core-shell adsorbents was also observed, which also contributed to the high adsorption capacity for cationic dyes. The reuse experiments showed that the adsorbents maintained the high adsorption capacity after 5 cycles. The high stability is crucial for practical application.

  • 12.
    Li, Kang
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211800, China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Cai, Juanjuan
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211800, China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 211800, China.
    Removal of dyes from aqueous solution using novel C @ C composite adsorbents2021In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 313, article id 110840Article in journal (Refereed)
    Abstract [en]

    In the present work, novel porous C@C composite adsorbents were prepared and applied for the adsorption of methylene blue (MB) and rhodamine B (RB). The adsorbents were prepared by carbonizing resorcinol–formaldehyde (RF) resins-coated ZIF-8 composites that obtained using an in-situ deposition method. The effect of RF/ZIF-8 ratio and carbonization temperature on the particle size, specific surface area and pore size was investigated. High adsorption capacity resulted from the high surface area of 1842 m2/g and a sufficient pore size of 4.4 nm. The effect of temperature, initial dyes concentration and pH on the adsorption capacity was investigated to optimize the adsorption conditions, and maximum adsorption capacity of 681 and 462 mg/g was observed for MB and RB, respectively. Langmuir model and pseudo-second-order adsorption kinetics model can be used to well describe the obtained adsorption isotherms. The estimated saturated adsorption capacity for MB and RB was 806 and 476 mg/g, respectively. The used C@C-1000 could be regenerated in methanol solution, and after 5 cycles, the adsorption capacity was maintained above 92% of the maximum.

  • 13.
    Matsakas, Leonidas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Gerber, Milena
    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.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Preparation of low carbon impact lignin nanoparticles with controllable size by using different strategies for particles recovery2020In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 147, article id 112243Article in journal (Refereed)
    Abstract [en]

    Lignin still remains an underutilized plentiful resource whose conversion to high-added value products is a cornerstone towards establishing a viable biomass biorefinery. Bio-materials in the form of nanoparticles represent promising high-value products with numerous downstream applications. The aim of the current work was to develop a method that would allow controlling the size of (birch and spruce) lignin nano- and micro-particles for their subsequent recovery into a solid product. We tested different two-step and one-step isolation processes and demonstrated that particle size could be easily controlled to meet different ranges (<100 nm, <500 nm, and>1 μm). In general, two-step isolation methods, i.e. a step of decrease of solvent concentration followed by isolation of lignin particles, were better for the isolation of well-defined spherical particles. In particular, the rate at which ethanol concentration was decreased played a significant role in determining the size of lignin particles. Moreover, when lignin concentration was increased from 1 % to 5 % and 10 % (w/v), particle size and homogeneity decreased slightly, but productivity augmented. The present study demonstrates that different isolation methods can be applied to obtain renewable, customarily sized, lignin spherical micro- and nano-particles.

  • 14.
    Miana, Marta Pérez
    et al.
    Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50018 Zaragoza, Spain; Chemical and Environmental Engineering Department, Universidad de Zaragoza, 50018 Zaragoza, Spain.
    Coronas, Joaquín
    Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50018 Zaragoza, Spain; Chemical and Environmental Engineering Department, Universidad de Zaragoza, 50018 Zaragoza, Spain.
    Hedlund, Jonas
    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.
    Highly permeable ZIF-8 membranes for C2H4/C2H6 separation in a wide temperature range2024In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 330, no Part A, article id 125329Article in journal (Refereed)
    Abstract [en]

    Ethylene/ethane separation is a critical and energy-consuming process in the chemical industry due to the similar properties of the compounds and the great need of ethylene for e.g., polymer production. Many materials have been studied for their implementation as membranes as an energetically favorable alternative to conventional distillation and adsorption processes. Metal-organic frameworks (MOF) have revealed promising properties as highly permeable and selective membranes. Among the most studied and promising MOF candidates is ZIF-8, known for its thermal stability and small pores connected by narrow-sized windows. In this work, we present an analysis of the influence of parameters such as temperature, feed pressure and feed flowrate on the separation of ethylene/ethane through a thin ZIF-8/alumina disc membrane. We observed that the temperature has a significant effect on the separation. The ethylene permeance increased with decreased temperature and reached 8.1 × 10−7 mol/(m2·s·Pa) at −30 °C. At this temperature, the ethylene/ethane selectivity was 2.5. The study concluded with a considerable enhancement of the permeance of ZIF-8 membranes for ethylene/ethane separations, while maintaining a good selectivity compared to the reported values in the literature. The results have important implications for the development of more cost-effective and energy-efficient membrane-based separation technologies for ethylene purification.

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  • 15.
    Nobandegani, Mojtaba Sinaei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Darbandi, Tayebeh
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Kheirinik, Mahdi
    Persian Gulf Star Oil Company.
    Birjandi, Mohammad Reza Sardashti
    Center of Process Integration and Control (CPIC), Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, PoBox: 98135-987, Iran.
    Shahraki, Farhad
    Center of Process Integration and Control (CPIC), Department of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, PoBox: 98135-987, Iran.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    One-dimensional Modelling and Optimisation of an Industrial Steam Methane Reformer2021In: Chemical and biochemical engineering quarterly, ISSN 0352-9568, E-ISSN 1846-5153, Vol. 35, no 4, p. 369-379Article in journal (Refereed)
    Abstract [en]

    Steam methane reforming is one of the most promising processes to convert natural gas into valuable products such as hydrogen. In this study, a one-dimensional model was used to model and optimise an industrial steam methane reformer, using mass and thermal balances coupled with pressure drop in the reformer tube. The proposed model was validated by the experimental data. Furthermore, the effects of flowrate and temperature of the feed, tube wall temperature, and tube dimension on the reformer performance were studied. Finally, a multiobjective optimisation was done for methane slip minimisation and hydrogen production maximisation using genetic algorithm. The results illustrated the optimum feed flowrate of 2761.9 kmol h–1 (minimum 32 mol.% produced hydrogen and maximum 0.15 mol.% unreacted methane). This is one of the few studies on investigation of steam methane reformer using a simple and effective model, and genetic algorithm.

  • 16.
    Nobandegani, Mojtaba Sinaei
    et al.
    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.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zeolite Membrane Process for Industrial CO2/CH4 Separation2022In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 446, no 4, article id 137223Article in journal (Refereed)
    Abstract [en]

    Zeolite membrane processes were designed for biogas upgrading for feed pressures ranging from 5 to 20 bar and compared with corresponding polymeric membrane processes. The mass transfer through zeolite membranes was estimated by a model accounting for adsorption and diffusion through the surface barriers and the interior of the pores, while the mass transfer through polymeric membranes was estimated using reported permeances for commercial polymeric membranes. The zeolite membranes displayed approximately three orders of magnitude higher permeance and up to 7 times higher selectivity. To reach a low methane loss, two and three membrane stages were needed for zeolite and polymeric membranes, respectively, because of the differences in selectivity. Due to the higher selectivity, the electricity need for the zeolite membrane process was only 50–60% of that for the corresponding polymeric membrane process. As a result of the much higher permeability, the zeolite membrane processes were much more compact than the equivalent polymeric membrane processes. The estimated cost for zeolite membranes prepared in small scale including modules was much lower than the cost for industrially produced polymeric membranes including modules.

  • 17.
    Nobandegani, Mojtaba Sinaei
    et al.
    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.
    Mayne, Benjamin
    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.
    Adsorption and transport of CO2 and CH4 in CHA zeolite2019Conference paper (Other academic)
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  • 18.
    Nobandegani, Mojtaba
    et al.
    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.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mass transport of CO2 over CH4 controlled by the selective surface barrier in ultra-thin CHA membranes2022In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 332, article id 111716Article in journal (Refereed)
    Abstract [en]

    The adsorption and mass transport of CO2 and CH4 in CHA zeolite were studied experimentally. First, large and well-defined CHA crystals with varying Si/Al ratios and morphologies ideal for adsorption studies were prepared. Then, adsorption isotherms were measured, and adsorption parameters were estimated from the data. In the next step, permeation experiments for pure components and mixtures were conducted for a defect-free CHA membrane with a Si/Al ratio of 80 and a thickness of 600 nm over a wide temperature range. A maximum selectivity of 243 in combination with a CO2 permeance of 70 × 10−7 mol/(m2 s Pa) was observed for a feed of an equimolar CO2/CH4 mixture at 273 K and 5.5 bar. Finally, a simple model accounting for adsorption and diffusion through the surface barriers and the interior of the pores of the membrane was fitted to the permeation data. The fitted model indicated that the surface barrier was a surface diffusion process at the pore mouth with higher activation energy than the diffusion process within the pores. The model also showed that the highly selective mass transport in the membrane was mostly a result of a selective surface barrier and, to a lesser extent, a result of adsorption selectivity.

  • 19.
    Shu, Jiahui
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, No. 30, Puzhu Road(s), Nanjing 211816, PR China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ding, Rong
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, No. 30, Puzhu Road(s), Nanjing 211816, PR China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, No. 30, Puzhu Road(s), Nanjing 211816, PR China.
    Efficient synthesis of polyether polyols in simple microreactors2021In: Reaction Chemistry & Engineering, E-ISSN 2058-9883, Vol. 6, no 4, p. 685-693Article in journal (Refereed)
    Abstract [en]

    Polyether polyols as a crucial chemical for the synthesis of polyurethanes have attracted much attention, especially for propylene oxide-based polyether polyols due to their ready availability and good structural diversity. In the present work, microreactors configured with a SIMM-V2 micromixer and stainless steel capillary were developed for the continuous and efficient synthesis of propylene oxide-based polyether polyols. For the conversion of propylene oxide higher than 95%, the reaction time was less than 60 s that was significantly shorter than that in a batch reactor. Also, the reaction temperature can be controlled precisely, thereby obtaining high purity polyether polyol products. To identify the maximum performance of the microreactors, while keeping the conversion of PO higher than 95%, the novel process windows of the reactors were determined by investigating the relations of reaction temperature and pressure, reaction temperature and residence time, and feed flow rate and residence time. The results showed that high quality polyether polyols could be easily prepared in the microreactors under flexible operating conditions. In addition, polyether polyols with higher molecular weights could also be prepared by using a two SIMM-V2 configured microreactor. This work showed that the microreactors are promising candidates for the synthesis of polyether polyols in the industry.

  • 20.
    Tong, Fei
    et al.
    School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China. State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
    Gong, Jie
    School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou 213001, China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Li, Ming
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
    Transparent and anti-fogging AlPO4-5 films constructed by oblique oriented nano-flake crystals2022In: Chinese Journal of Chemical Engineering, ISSN 1004-9541, E-ISSN 2210-321X, Vol. 44, p. 332-340Article in journal (Refereed)
    Abstract [en]

    In the present work, transparent and anti-fogging AlPO4-5 films were prepared on glass substrates using a novel developed process. The process entails a simple in-situ sol-gel followed by vapor phase transport. The in-situ sol-gel process was implemented by coating the precursor sols for the synthesis of AlPO4-5 on the glass substrates successively using the spin-coating method. The films and powders scribed from the films were characterized by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). The unique films were composed of oblique oriented nano-flake AlPO4-5 crystals with the thickness of about 20 nm. The formation of nano-flake crystals can be ascribed to the high concentration of the precursors, resulting in the formation of a supersaturation system. The obtained films showed high antifogging performance due to the superhydrophilicity with a water contact angle of lower than 1.0°. The silicone oil contact angle was also low about 8.2°. In addition, heteroatom-substituted AlPO4-5 films showing different colors can be obtained easily by simply adding transition metal ions in the phosphate acid solution during the preparation that can extend the application of the method for different coating demand.

  • 21.
    Wang, Liwei
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing, P. R. China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zeng, Changfeng
    College of Mechanical and Power Engineering , Nanjing Tech University , Nanjing , P. R. China. .
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing, P. R. China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemical Engineering , Nanjing Tech University , Nanjing, P. R. China.
    Fabrication of PAA-PETPTA Janus Microspheres with Respiratory Function for Controlled Release of Guests with Different Sizes2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 24, p. 7106-7116Article in journal (Refereed)
    Abstract [en]

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

  • 22.
    Yan, Baili
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Yu, Shuang
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Zeng, Changfeng
    College of Mechanic and Power Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Binderless zeolite NaX microspheres with enhanced CO2 adsorption selectivity2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 278, p. 267-274Article in journal (Refereed)
    Abstract [en]

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

  • 23.
    Yan, Baili
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing .
    Zeng, Changfeng
    College of Mechanic and Power Engineering, Nanjing Tech University.
    Yu, Liang
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Preparation of hollow zeolite NaA/chitosan composite microspheres via in situ hydrolysis-gelation-hydrothermal synthesis of TEOS2018In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 257, p. 262-271Article in journal (Refereed)
    Abstract [en]

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

  • 24.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Al-Jariry, Nadin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Serikbayeva, Toizhan
    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.
    Ultra-thin zeolite CHA and FAU membranes for desalination by pervaporation2022In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 294, article id 121177Article in journal (Refereed)
    Abstract [en]

    In the present work, ultra-thin zeolite CHA and FAU membranes, with thicknesses of 600 and 500 nm, respectively, were evaluated for desalination by pervaporation at various temperatures. Single gas permeation experiments were employed to verify high quality of the membranes. At 90 °C, the observed water fluxes for CHA and FAU membranes were as high as 24 and 28 kg/(m2‧h), respectively. A mathematical model was used to estimate the effect of the support. The results showed that the mass transfer resistance of the support reduced the flux. The water flux corrected for the mass transfer resistance over the support was as high as 40 and 51 kg/(m2‧h) at 90 °C for CHA and FAU membranes, respectively. To the best of our knowledge, these are the highest reported water fluxes for desalination by zeolite membranes in a pervaporation process.

  • 25.
    Yu, Liang
    et al.
    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.
    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.
    Ultra-thin MFI membranes with different Si/Al ratios for CO2/CH4 separation2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 284, p. 258-269Article in journal (Refereed)
    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.

  • 26.
    Yu, Liang
    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.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ultra-thin MFI membranes for removal of C3+ hydrocarbons from methane2018In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 551, p. 254-260Article in journal (Refereed)
    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. 

  • 27.
    Yu, Liang
    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.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ultra-thin MFI membranes for olefin/nitrogen separation2017In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 524, p. 428-435Article in journal (Refereed)
    Abstract [en]

    The recovery of light hydrocarbons such as propylene and ethylene from vent streams in polymer plants is desirable since it opens up for more efficient conversion of the monomers with high economic value. Consequently, polymer membrane vapour-gas separation systems have been used for this purpose for decades [1,2]. However, an alternative is zeolite membranes. In this work, ultra-thin MFI zeolite membranes (0.5 µm) were used to separate propylene or ethylene from binary 20/80 olefin/nitrogen mixtures at different temperatures. The membranes were olefin selective with high permeance at all investigated temperatures. At room temperature, the permeance of propylene was 22×10-7 mol m-2 s-1 Pa-1 and the separation factor was 43, which corresponds to a separation selectivity of around 80. For a mixture of 20 mol.% ethylene in nitrogen, the maximum separation factor was 6 (corresponds to a separation selectivity of 8.4) at 277 K with an ethylene permeance of 57×10-7 mol m-2 s-1 Pa-1. The membrane selectivity was governed by more extensive adsorption of olefin, especially propylene, as compared to nitrogen. Comparing with ethylene, propylene has higher heat of adsorption, which probably caused the higher propylene/nitrogen selectivity compared to ethylene/nitrogen selectivity. The permeance and the selectivity for propylene were much higher than for commercial polymeric membranes. For ethylene, the permeance was much higher, and the selectivity was comparable to commercial polymeric membranes. Modelling showed that the pressure drop over the support limited the flux through the membranes especially at higher temperatures and in particular for the ethylene/nitrogen system with high flux. Further, modelling indicated that the result obtained at high temperatures, where the flux was high, was also affected by concentration polarization. However, for the propylene/nitrogen system at the optimum separation temperature, the pressure drop over the support and the concentration polarisation were small. The results show that ultra-thin MFI zeolite membranes are promising candidates for light olefins/nitrogen separation in polymer plants.

  • 28.
    Yu, Liang
    et al.
    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.
    Large and Highly Selective and Permeable CHA Zeolite Membranes2023In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 62, no 39, p. 16058-16069Article in journal (Refereed)
    Abstract [en]

    Large (100 cm2 membrane area) tubular chabazite (CHA) zeolite membranes (450 nm thick) were experimentally evaluated for the separation of CO2/CH4 in an industrial laboratory. An industrially relevant feed flow rate of 250 Ndm3/min was used. The feed pressure and temperature were varied in the ranges of 5–18 bar and 292–318 K, respectively. For a CO2/CH4 feed with a molar ratio of 1:1, the experimental CO2/CH4 selectivity was high at 205, and the CO2 permeance arrived at 52 × 10–7 mol/(m2·s·Pa) at 5 bar and 292 K. As far as we know, there is no report in the literature on large CHA membranes with such high permeability and selectivity. A high CO2/CH4 selectivity was also observed for a 1:4 CO2/CH4 feed. However, as indicated by mathematical modeling, concentration polarization was still an issue for membrane performance, especially at high operating pressures, even though the flow rate of the feed was relatively high. Without concentration polarization, the theoretical CO2/CH4 selectivity was 41% higher than the experimental value for a 1:1 CO2/CH4 feed at 18 bar. The corresponding CO2 permeance without concentration polarization was 23% higher than the experimentally observed value, reaching 34 × 10–7 mol/(m2·s·Pa). CHA membrane processes for the removal of CO2 from CH4 were designed, and the electricity consumption and module cost of the process were also estimated. All of the results in this study indicate a great potential of the large CHA membranes for biogas and natural gas upgrading; however, concentration polarization should be minimized in industrial processes.

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  • 29.
    Yu, Liang
    et al.
    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.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Biogas upgrading by zeolite membranes2016Conference paper (Other academic)
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  • 30.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Holmgren, Allan
    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 novel method for fabrication of high-flux zeolite membranes on supports with arbitrary geometry2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10325-10330Article in journal (Refereed)
    Abstract [en]

    A novel procedure for the preparation of high-flux zeolite membranes was developed. This method relies on rendering the support hydrophobic, and thereby protected from the synthesis mixture and invasion of the support pores, while the cationic polymer on the surface still allowed deposition of zeolite seeds. Both high-flux MFI and CHA zeolite films were grown on both discs and tubular supports, which illustrates the applicability of the method to arbitrary membrane geometries. Typically, MFI disc membranes showed a very high CO2permeance of 85 × 10−7 mol m−2 s−1 Pa−1 and a CO2/H2 separation selectivity of 56 at 278 K and CHA disc membranes showed a very high CO2 permeance of 79 × 10−7 mol m−2 s−1 Pa−1 and a CO2/CH4 separation selectivity of 76 at 249 K. As the method is applicable to supports with complex geometries, it is suitable for preparation of membranes for industrial applications.

  • 31.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Holmgren, Allan
    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.
    Highly permeable CHA membranes prepared by fluoride synthesisfor efficient CO2/CH4 separation2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 16, p. 6847-6853Article in journal (Refereed)
    Abstract [en]

    All-silica CHA nanocrystals, much smaller (20–200 nm) than previously reported, were prepared by an improved method developed in the present work. The nanocrystals are prepared by adding milled crystals to a fluoride synthesis mixture and we observed that much smaller crystals are obtained by adding a much higher fraction of milled crystals. In the next step, CHA membranes with a thickness of ca. 1.3 μm were prepared by hydrothermal treatment of a monolayer of nanocrystals supported on porous graded alumina discs in a fluoride synthesis gel. Finally, the membranes were calcined at 480 °C. The highest measured single gas CO2 permeance was 172 × 10−7 mol m−2 s−1 Pa−1 at room temperature. The highly permeable membranes were evaluated for separation of CO2 from an equimolar mixture with CH4 at varying temperatures. The highest observed CO2 mixture permeance was 84 × 10−7 mol m−2 s−1 Pa−1 at 276 K with a separation selectivity of 47 at 9 bar feed pressure and atmospheric permeate pressure. At room temperature, the CO2 mixture permeance was also as high as 78 × 10−7 mol m−2 s−1 Pa−1 with a separation selectivity of 32. To the best of our knowledge, these CO2 permeances are by far the highest reported for CHA membranes, while the selectivity is similar to that reported previously at comparable test conditions.

  • 32.
    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.

  • 33.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Kyriazidou, Iliana
    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.
    Highly permeable DDR membranes2023In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 687, article id 122039Article in journal (Refereed)
    Abstract [en]

    In this study, DDR membranes with a layer thickness of approximately 700 nm were studied for separation feeds comprising mixtures of CO2 and CH4. The membranes displayed the highest CO2 over CH4 permselectivity and CO2 permeability reported in literature. This was ascribed to a defect-free and ultra-thin zeolite film as well as an open and highly permeable support. For equimolar mixtures, the highest CO2 over CH4 permselectivity of 727 was observed when the pressure at the feed side was 5 bar(a) and the permeate pressure was 1 bar(a) at 25 °C. At these conditions, the CO2 permeability was very high at 45 × 10−7 mol/(m2 s Pa). Separation experiments for 80/20 and 20/80 mixtures were also performed, and in these cases, CO2 over CH4 permselectivities of 1011 and 622 were observed, respectively. For all feeds, the membrane permselectivity decreased slightly at higher temperature and in all cases, higher permselectivity was observed when vacuum was applied at the permeate side. One-stage membrane processes for upgrading biogas to biomethane at three different operating pressures were designed based on the experimental data. In all cases, a quite low membrane area, methane slip and power need were observed.

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  • 34.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Liu, Dong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Yan, Baili
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Zeng, Changfeng
    College of Mechanic and Power Engineering, Nanjing Tech University.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    A Universal Biological-materials-assisted Hydrothermal Route to Prepare Various Inorganic Hollow Microcapsules in the Presence of Pollens2016In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 301, p. 26-33Article in journal (Refereed)
    Abstract [en]

    A universal bio-economical hydrothermal route has been developed to prepare various inorganic hollow microcapsules with the help of rapeseed pollens for the first time. The pollens were used without any modifications. TiO2, ZnO, zeolite ZSM-5, BaTiO3 and ZnS were prepared by this route using the regular synthesis solutions added with rapeseed pollens. The obtained products were examined by scanning and transmission electron microscopy, X-ray diffraction, FT-IR, N2 adsorption and thermogravimetric analysis. The hollow microcapsules are composed of inorganic particles around the derivations of pollens. And the diameter of the hollow has been demonstrated almost the same size as the derivations microspheres. The derivations were decomposed in high temperature crystallization procedure; therefore, no additional procedure is needed to remove the templates for the hollow structure. The hollow microcapsules prepared with rapeseeds have much higher specific surface area. The formation mechanism can be ascribed to the template effect of derivative microspheres formed from decomposition of these pollen grains. Furthermore, other pollens are also used in the preparation by the universal hydrothermal route. Still, inorganic hollow microcapsules but with different hollow diameters were obtained probably resulting from the different size of the derivations.

  • 35.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mayne, Benjamin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba Sinaei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grekou, Triantafyllia
    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.
    Recovery of helium from natural gas using MFI membranes2022In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 644, article id 120113Article in journal (Refereed)
    Abstract [en]

    The development of more efficient technology for the production of helium from natural gas is pressing as the current resources are dwindling. In the present work, ultra-thin MFI membranes were evaluated for the separation of an equimolar CH4/N2/He mixture in a wide temperature range 120–293K. The membrane was highly selective towards CH4 and N2 at all the investigated conditions, which resulted in a helium rich retentate. The observed selectivity should be a result of selective adsorption of CH4 and N2. A maximum (CH4+N2)/He separation factor of 152 was observed at 153 K and a feed pressure of 3 bar and a permeate pressure of 0.2 bar. At these conditions, separation factors were 265 and 38 for CH4/He and N2/He, respectively, and the CH4 and N2 fluxes were 1.12 and 0.16 mol/(m2⋅s), respectively. To the best of our knowledge, these are the best results reported in the open literature for the recovery of helium from natural gas using membrane technology. The high selectivity and flux indicated that the ultra-thin MFI membranes are a promising candidate for efficient helium production from natural gas.

  • 36.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba
    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 performance fluoride MFI membranes for efficient CO2/H2 separation2020In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 616, article id 118623Article in journal (Refereed)
    Abstract [en]

    In the present work, ultra-thin MFI zeolite membranes with a thickness of about 450 nm prepared in fluoride media were evaluated for separation of equimolar CO2/H2 gas mixtures. Both dry and humid mixtures were evaluated. For dry gas mixtures, the membrane selectivity increased from 13 to 45 when the temperature decreased from 318 to 285 K, and CO2 flux was very high and almost constant at 4 mol m−2 s−1, corresponding to CO2 permeance of 100 × 10−7 mol m−2 s−1 Pa−1 (29851 GPU). For humid gas mixtures with a partial pressure of water of 3.5 kPa, the CO2 flux decreased from 3.27 to 0.10 mol m−2 s−1 when the temperature decreased from 316 to 288 K. The corresponding CO2 permeance decreased from 79 to 2.5 × 10−7 mol m−2 s−1 Pa−1 (from 23582 to 746 GPU). At the highest temperature 318 K, the CO2/Hseparation selectivity was slightly higher for the humid gas mixture. For the humid gas mixture, the CO2 flux increased from 3.27 to 3.76 mol m−2 s−1 at 318 K and from 0.52 to 0.90 mol m−2 s−1 at 296 K when the permeate pressure was reduced from atmospheric to vacuum, respectively. The separation selectivity of CO2/H2 was almost not affected by the permeate pressure. The results show that ultra-thin fluoride MFI zeolite membranes are promising candidates for separation of CO2 from dry or humid synthesis gas.

  • 37.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba
    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.
    Highly permeable and selective CHA membranes for efficient CO2/CH4 separation2019Conference paper (Refereed)
  • 38.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba
    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.
    Industrially relevant CHA membranes for CO2/CH4 separation2022In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 641, article id 119888Article in journal (Refereed)
    Abstract [en]

    In the present work, single channel tubular zeolite CHA membranes with a length of 50 cm and a membrane area of 100 cm2 were evaluated by SEM and permeation experiments with single components and industrially relevant humid mixtures. The membranes comprised well-intergrown and smooth CHA films with a thickness of <500 nm supported on the inside of a highly porous tube. For single component permeation, a very low SF6 permeance of 4.5 × 10−10 mol/(m2‧s‧Pa) was observed, which indicated nearly defect free membranes. On the contrary, the membranes displayed a very high CO2 permeance of 128 × 10−7 mol/(m2‧s‧Pa), which illustrated the very high permeability of the CHA pores. Finally, the membranes displayed excellent selectivity for separation of industrially relevant CO2/CH4/H2O mixtures, which was attributed to selective interaction between the CO2 molecules and the polar water molecules in the pores. The highest observed CO2/CH4 separation selectivity was as high as 198 in combination with a CO2 permeance of 14 × 10−7 mol/(m2‧s‧Pa) at a feed pressure of 600 kPa (including 2.2 kPa water) and 293K. The corresponding CO2 flux was 0.39 mol/(m2‧s) and the corresponding CO2/CH4 separation factor was 162. The observed membrane performance was reduced by concentration polarisation due to the limited feed flow in the experimental setup. The corresponding selectivity and CO2 permeance corrected for concentration polarisation were as high as 236 and 16 × 10−7 mol/(m2‧s‧Pa), and the corrected CO2 flux was 0.44 mol/(m2‧s) and corrected separation factor was 198. An estimate showed that even at a low feed pressure of 500 kPa, it would be sufficient with as few as 64 membranes for processing of a feed of 100 Nm3/h raw biogas, i.e. the capacity of a typical biogas plant at a large farm, to biomethane with high purity. These results illustrated that the membranes are promising candidates for industrial separation of CO2 from e.g. natural gas and biogas.

  • 39.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nobandegani, Mojtaba Sinaei
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Holmgren, Allan
    ZeoMem Sweden AB, Luleå, Sweden.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Highly permeable and selective tubular zeolite CHA membranes2019In: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 588, article id 117224Article in journal (Refereed)
    Abstract [en]

    Highly permeable and selective tubular zeolite CHA membranes with a thickness of about 450 nm and a length of 100 mm and an inner diameter of 7 mm were evaluated by single gas permeation experiments and for separation of an equimolar CO2/CH4 mixture. The membranes displayed high H2 and CO2 single gas permeances of 55 × 10−7 mol m−2 s−1 Pa−1 and 94 × 10−7 mol m−2 s−1 Pa−1, respectively, and a very low SF6 permeance of 3 × 10−9 mol m−2 s−1 Pa−1. The highest observed mixture separation factor was 99 with CO2 permeance of 60 × 10−7 mol m−2 s−1 Pa−1 at a feed pressure of 5 bar and permeate pressure of 0.12 bar. The corresponding CO2flux was 1.46 mol m−2 s−1. The highest observed flux was 1.98 mol m−2 s−1 with a separation factor of 52 at a feed pressure of 10 bar and permeate pressure of 0.12 bar at room temperature. To the best of our knowledge, this is the first report describing highly permeable and selective tubular CHA membranes. The results indicate that the membranes have a great potential for industrial separation of CO2from natural gas and biogas.

  • 40.
    Yu, Liang
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
    Zeng, Changfeng
    College of Mechanic and Power Engineering, Nanjing Tech University.
    Wang, Chongqing
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Zhang, Lixiong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing.
    In situ impregnation−gelation−hydrothermal crystallization synthesis of hollow fiber zeolite NaA membrane2017In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 244, p. 278-283Article in journal (Refereed)
    Abstract [en]

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

  • 41.
    Zhou, Ming
    et al.
    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.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ultrathin DDR Films with Exceptionally High CO2 Flux and Uniformly Adjustable Orientations2022In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 32, no 18, article id 2112427Article in journal (Refereed)
    Abstract [en]

    Thin and oriented zeolite films are important for advanced separations, catalysis, and sensing. Strategies for tailoring zeolites for applications include controlling their crystal size, shape, and orientation. Here, three siliceous DDR zeolite ultrathin films with different orientations achieved by homoepitaxial growth from 60 nm-sized seed particles are reported. The 0.5 µm thick membrane shows a separation selectivity of 400 for CO2–CH4 mixtures and CO2 permeance of 25 × 10-7 mol m-2 s-1 Pa-1 at 20 °C and 1 bar, leading to a record-high performance among all reported DDR membranes. Furthermore, the seed nanoparticles are grown into mono-dispersed DDR sub-micron crystals with trigonal and tabular habits. These crystals are assembled in monolayers for the growth of ultrathin and uniformly (h0h)-oriented and c-oriented films with maximum surface pore diameter of 0.365 and 0.263 nm, respectively, by using the 1-adamantanamine template in fluoride medium. The novel strategy not only provides high-performance membrane candidates for industrial CO2 separation, but also inspires interfacial engineering, pore size, and orientation controlling for other microporous crystals, and their membranes.

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