High-performance ammonia-selective MFI nanosheet membranes

2021 ◽  
Author(s):  
Xuekui Duan ◽  
Donghun Kim ◽  
Katabathini Narasimharao ◽  
Shaeel Al-Thabaiti ◽  
Michael Tsapatsis
Keyword(s):  
Separation Factor ◽  
High Performance ◽  
Hydrogen Separation ◽  
Mfi Zeolite ◽  
Industrial Use ◽  
High Separation Factor ◽  
High Separation

MFI zeolite nanosheet membranes exhibit high separation factor and flux for the separation of ammonia over hydrogen and nitrogen and hold promise for industrial use. These membranes also exhibit high performance for hydrogen separation from hydrocarbons.

scholarly journals VTOS Cross-Linked PDMS Membranes for Recovery of Ethanol from Aqueous Solution by Pervaporation

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jin Gu ◽  
Yunxiang Bai ◽  
Lin Zhang ◽  
Lirong Deng ◽  
Chunfang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Separation Factor ◽  
Pdms Membrane ◽  
Total Flux ◽  
Cross Linking ◽  
High Separation Factor ◽  
Ethanol Aqueous Solution ◽  
High Ethanol ◽  
Feed Temperature ◽  
High Separation

PDMS membranes were prepared by cross-linking with vinyltriethoxysilane (VTOS) on polyacrylonitrile (PAN) substrate to increase hydrophobicity and improve pervaporation (PV) performance. It was shown that the membranes had high ethanol permselectivity and flux. The effects of cross-linking temperature, the content of cross-linking agent, and feed temperature on PV performance of VTOS cross-linked PDMS membranes were investigated. For 6 wt% ethanol aqueous solution, the PDMS membrane had the high separation factor of 15.5 and total flux 573.3 g·m−2·h−1, respectively, when the feed temperature was 40°C, H-PDMS : VTOS : DBTDL = 1 : 0.2 : 0.02 and cross-linking temperature was 80°C.

Simultaneous separation of Am and Cm from Nd and Sm by multi-step extraction using the TODGA-DTPA-BA-HNO3 system

2020 ◽  
Vol 108 (9) ◽  
pp. 689-699 ◽  
Author(s):  
Yuji Sasaki ◽  
Keisuke Morita ◽  
Masahiko Matsumiya ◽  
Masahiko Nakase
Keyword(s):  
Separation Factor ◽  
Chemical Behavior ◽  
Trivalent Metal ◽  
Basic Study ◽  
Ionic Radii ◽  
Simultaneous Separation ◽  
Separation Factors ◽  
Trivalent Metal Ions ◽  
High Separation Factor ◽  
High Separation

AbstractThe simultaneous separation of Am and Cm from lanthanides is important for atomic energy fields. However, the process is difficult owing to the chemical behavior of trivalent metal ions with similar ionic radii. All lanthanides, Am, and Cm can be extracted by diglycolamide (DGA). In addition, relatively high separation factors between An and Ln were obtained by the extraction system of TODGA, DTPA (diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid) and HNO3. In this work, DTPA-BA (diethylenetriamine-N,N′,N″-triacetic-N,N″-bisamide), which is an improved version of DTPA, was employed for the separation of Ln and An. After performing a basic study on DTPA-BA, a relatively high separation factor (approximately 8) for actinides/lanthanides was obtained. Then, the multi-step extraction was performed. Thus, the recoveries of 94.7 % for Nd and 4.7 % for Am and Cm in organic phase, and 5.3 % Nd and 95.3 % for Am and Cm in aqueous phase were obtained.

Fundamental Study on Multistage Extraction Using TDdDGA for Separation of Lanthanides Present in Nd Magnets

JOM ◽  
2021 ◽  
Author(s):  
Yuji Sasaki ◽  
Keisuke Morita ◽  
Masahiko Matsumiya ◽  
Ryoma Ono ◽  
Hidenobu Shiroishi
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Separation Factor ◽  
Basic Research ◽  
Fundamental Study ◽  
High Separation Factor ◽  
High Separation

AbstractThe separation of Dy from Nd has been studied from the viewpoint of recycling Dy from Nd magnets. N,N,N′,N′-tetradodecyl-DGA (TDdDGA) has a relatively high separation factor between Dy and Nd (above 10) in HNO3 medium. After basic research on batchwise multistage extractions using eight extraction stages with 0.1 M TDdDGA in n-dodecane as organic phase, ten stages with an aqueous phase (0.7 M HNO3 with metals), and six stages with another aqueous phase (0.7 M HNO3 without metals), approximately 99% of Dy was recovered into the organic phase with 1% coextraction of Nd.

scholarly journals Enhancing Pervaporation Membrane Selectivity by Incorporating Star Macromolecules Modified with Ionic Liquid for Intensification of Lactic Acid Dehydration

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1811
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Roman Dubovenko ◽  
Ilya Faykov ◽  
Kseniya Subbotina ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Lactic Acid ◽  
Polymer Matrix ◽  
Separation Factor ◽  
Membrane Structure ◽  
High Performance ◽  
Separation Efficiency ◽  
Pharmaceutical Chemical ◽  
Permeate Flux ◽  
Membrane Components

Modification of polymer matrix by hybrid fillers is a promising way to produce membranes with excellent separation efficiency due to variations in membrane structure. High-performance membranes for the pervaporation dehydration were produced by modifying poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) to facilitate lactic acid purification. Ionic liquid (IL), heteroarm star macromolecules (HSM), and their combination (IL:HSM) were employed as additives to the polymer matrix. The composition and structure of hybrid membranes were characterized by X-ray diffraction and FTIR spectroscopy. Scanning electron microscopy was used to investigate the membranes surface and cross-section morphology. It was established that the inclusion of modifiers in the polymer matrix leads to the change of membrane structure. The influence of IL:HSM was also studied via sorption experiments and pervaporation of water‒lactic acid mixtures. Lactic acid is an essential compound in many industries, including food, pharmaceutical, chemical, while the recovering and purifying account for approximately 50% of its production cost. It was found that the membranes selectively remove water from the feed. Quantum mechanical calculations determine the favorable interactions between various membrane components and the liquid mixture. With IL:HSM addition, the separation factor and performance in lactic acid dehydration were improved compared with pure polymer membrane. The best performance was found for (HSM: IL)-PPO/UPM composite membrane, where the permeate flux and the separation factor of about 0.06 kg m−2 h−1 and 749, respectively, were obtained. The research results demonstrated that ionic liquids in combination with star macromolecules for membrane modification could be a promising approach for membrane design.

Preparation of Silicalite-1 Membranes with Seeding Method and its Separation Performance for Low Ethanol/Water Mixture

2013 ◽  
Vol 807-809 ◽  
pp. 591-595
Author(s):  
Hong Liang Chen ◽  
Ji Song Yang ◽  
Yan Wang ◽  
Hui Ying Li ◽  
Xin Xin Li ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Separation Factor ◽  
High Performance ◽  
Separation Performance ◽  
Water Mixture ◽  
Synthesis Conditions ◽  
Seeding Method

High performance silicalite-1 membranes were successfully synthesized on silica tubes by seeding method after filling the tubes with water and glycerol mixtures. After seeding the silica tubes with 200 nm seeds, all the silicalite-1 membranes show acceptable separation performance towards ethanol/water mixture after 4-12 h hydrothermal synthesis, and the highest flux of membrane with 8 h hydrothermal synthesis reaches about 0.98 kg/m2.h and the separation factor reaches about 60 towards 3 wt.% ethanol/water mixture. This result shows that the as-synthesized silicalite-1 membrane can concentrate the ethanol from 3% to about 65%, and the ethanol can be obtained over 600 g/m2.h by using the silicalite-1 membrane, which shows that seeding method and suitable control of synthesis conditions is possible for preparing high-performance silicalite-1 membranes.

Bayberry-like ZnO/MFI zeolite as high performance methanol-to-aromatics catalyst

2016 ◽  
Vol 52 (10) ◽  
pp. 2011-2014 ◽  
Author(s):  
Ning Wang ◽  
Weizhong Qian ◽  
Kui Shen ◽  
Chang Su ◽  
Fei Wei
Keyword(s):  
High Performance ◽  
Catalytic Efficiency ◽  
Mfi Zeolite ◽  
Zeolite Structure ◽  
Zeolite P ◽  
Two Sides

A unique bayberry-shaped MFI zeolite structure with a zeolite shell (1–1.5 μm in thickness) and numerous zeolite nanowires (500–800 nm in length) vertically grown on two sides of the shell is prepared. The catalytic efficiency is significantly higher than that of the conventional ZnO/MFI zeolite.

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