scholarly journals Hydrophobic *BEA-Type Zeolite Membranes on Tubular Silica Supports for Alcohol/Water Separation by Pervaporation

Membranes ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 86 ◽  
Author(s):  
Kyohei Ueno ◽  
Saki Yamada ◽  
Toshinari Watanabe ◽  
Hideyuki Negishi ◽  
Takuya Okuno ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Separation Performance ◽  
Water Mixture ◽  
Water Separation ◽  
Zeolite Membranes ◽  
Pure Silica ◽  
Large Pore ◽  
Silica Supports ◽  
Alcohol Water ◽  
Type Zeolite

Hydrophobic pure-silica *BEA-type zeolite membranes with large pores were prepared on tubular silica supports by hydrothermal synthesis using a secondary growth method and were applied to the separation of alcohol/water mixtures by pervaporation (PV), an alternative energy-efficient process for production of biofuels. Amorphous pure-silica tubular silica supports, free of Al atoms, were used for preparing the membranes. In this study, the effects of the synthesis conditions, such as the H2O/SiO2 and NH4F/SiO2 ratios in the synthetic gel, on the membrane formation process and separation performance were systematically investigated. The successfully prepared dense and continuous membranes exhibited alcohol selectivity and high flux for the separation of ethanol/water and butanol/water mixtures. The pure-silica *BEA membranes obtained under optimal conditions (0.08SiO2:0.5TEAOH:0.7NH4F:8H2O) showed high PV performance with a separation factor of 229 and a flux of 0.62 kg·m−2·h−1 for a 1 wt % n-butanol/water mixture at 318 K. This result was attributed to the hydrophobicity and large pore size of the pure-silica *BEA membrane. This was the first successful synthesis of hydrophobic large-pore zeolite membranes on tubular supports with alcohol selectivity, and the obtained results could provide new insights into the research on hydrophobic membranes with high permeability.

Fabrication of pure-silica *BEA-type zeolite membranes on tubular silica supports coated with dilute synthesis gel via steam-assisted conversion

2020 ◽  
Vol 247 ◽  
pp. 116934 ◽  
Author(s):  
Kyohei Ueno ◽  
Saki Yamada ◽  
Hideyuki Negishi ◽  
Takuya Okuno ◽  
Hiromasa Tawarayama ◽  
...  
Keyword(s):  
Zeolite Membranes ◽  
Pure Silica ◽  
Silica Supports ◽  
Type Zeolite

scholarly journals Gravity-Driven Separation of Oil/Water Mixture by Porous Ceramic Membranes with Desired Surface Wettability

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 457
Author(s):  
Chunlei Ren ◽  
Wufeng Chen ◽  
Chusheng Chen ◽  
Louis Winnubst ◽  
Lifeng Yan
Keyword(s):  
Porous Ceramic ◽  
Ceramic Membranes ◽  
Separation Performance ◽  
Water Mixture ◽  
Alumina Membrane ◽  
Water Separation ◽  
Alumina Membranes ◽  
Oil Water Separation ◽  
Gravity Driven ◽  
Oil Water

Porous Al2O3 membranes were prepared through a phase-inversion tape casting/sintering method. The alumina membranes were embedded with finger-like pores perpendicular to the membrane surface. Bare alumina membranes are naturally hydrophilic and underwater oleophobic, while fluoroalkylsilane (FAS)-grafted membranes are hydrophobic and oleophilic. The coupling of FAS molecules on alumina surfaces was confirmed by Thermogravimetric Analysis and X-ray Photoelectron Spectroscopy measurements. The hydrophobic membranes exhibited desired thermal stability and were super durable when exposed to air. Both membranes can be used for gravity-driven oil/water separation, which is highly cost-effective. The as-calculated separation efficiency (R) was above 99% for the FAS-grafted alumina membrane. Due to the excellent oil/water separation performance and good chemical stability, the porous ceramic membranes display potential for practical applications.

scholarly journals Development of Methanol Permselective FAU-Type Zeolite Membranes and Their Permeation and Separation Performances

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 627
Author(s):  
Ayumi Ikeda ◽  
Chie Abe ◽  
Wakako Matsuura ◽  
Yasuhisa Hasegawa
Keyword(s):  
Separation Factor ◽  
Carbon Number ◽  
Zeolite Membrane ◽  
Separation Performance ◽  
Solvent Mixtures ◽  
Permeation Flux ◽  
Aqueous Mixtures ◽  
Chemical Production ◽  
Zeolite Membranes ◽  
Type Zeolite

The separation of non-aqueous mixtures is important for chemical production, and zeolite membranes have great potential for energy-efficient separation. In this study, the influence of the framework structure and composition of zeolites on the permeation and separation performance of methanol through zeolite membranes were investigated to develop a methanol permselective zeolite membrane. As a result, the FAU-type zeolite membrane prepared using a solution with a composition of 10 SiO2:1 Al2O3:17 Na2O:1000 H2O showed the highest permeation flux of 86,600 μmol m−2 s−1 and a separation factor of 6020 for a 10 wt% methanol/methyl hexanoate mixture at 353 K. The membrane showed a molecular sieving effect, reducing the single permeation flux of alcohol with molecular size for single-component alcohols. Moreover, the permeation flux of methanol and the separation factor increased with an increase in the carbon number of the alcohols and methyl esters containing 10 wt% methanol. In this study, the permeation behavior of FAU-type zeolite membranes was also discussed based on permeation data. These results suggest that the FAU-type zeolite membrane has the potential to separate organic solvent mixtures, such as solvent recycling and membrane reactors.

Microstructural optimization of MFI-type zeolite membranes for ethanol–water separation

2014 ◽  
Vol 2 (38) ◽  
pp. 16093-16100 ◽  
Author(s):  
Yong Peng ◽  
Huibin Lu ◽  
Zhengbao Wang ◽  
Yushan Yan
Keyword(s):  
Water Separation ◽  
Zeolite Membranes ◽  
Type Zeolite ◽  
Microstructural Optimization

scholarly journals Sustainable, Highly Efficient and Superhydrophobic Fluorinated Silica Functionalized Chitosan Aerogel for Gravity-Driven Oil/Water Separation

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 66
Author(s):  
Zhongjie Zhu ◽  
Lei Jiang ◽  
Jia Liu ◽  
Sirui He ◽  
Wei Shao
Keyword(s):  
Separation Efficiency ◽  
Dimensional Structure ◽  
Separation Performance ◽  
High Porosity ◽  
Water Mixture ◽  
Water Separation ◽  
Highly Efficient ◽  
Oil Water Separation ◽  
Gravity Driven ◽  
Oil Water

A superhydrophobic fluorinated silica functionalized chitosan (F-CS) aerogel is constructed and fabricated by a simple and sustainable method in this study in order to achieve highly efficient gravity-driven oil/water separation performance. The fluorinated silica functionalization invests the pristine hydrophilic chitosan (CS) aerogel with promising superhydrophobicity with a water contact angle of 151.9°. This novel F-CS aerogel possesses three-dimensional structure with high porosity as well as good chemical stability and mechanical compression property. Moreover, it also shows striking self-cleaning performance and great oil adsorption capacity. Most importantly, the as-prepared aerogels exhibits fast and efficient separation of oil/water mixture by the gravity driven process with high separation efficiency. These great performances render the prepared F-CS aerogel a good candidate for oil/water separation in practical industrial application.

scholarly journals Synthesis of C-Plane Oriented Hexagonal Tungsten Oxide Membranes on Tubular Substrates and Their Acetic Acid/Water Separation Performances

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Hiroto Kunishi ◽  
Shintaro Wada ◽  
Yuki Kamimoto ◽  
Ryoichi Ichino ◽  
Yan Lin ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Tungsten Oxide ◽  
Separation Performance ◽  
Water Mixture ◽  
Water Separation ◽  
Synthesis Conditions ◽  
Plane Orientation ◽  
Acetic Acid Water ◽  
Hexagonal Tungsten Oxide ◽  
Water Permeance

Hexagonal tungsten oxide (h-WO3) membrane is a novel candidate for dehydration of acetic acid (CH3COOH)/water mixtures owing to its molecular sieving property and acidic resistance. Meanwhile, c-plane orientation is an important factor for h-WO3 membranes because the pores of h-WO3 run along its c-axis. However, so far, high c-plane orientation has not been successful on tubular substrates. Here, the effect of synthesis conditions of h-WO3 membranes on tubular substrates against c-plane orientation and CH3COOH/water separation performance are investigated. The h-WO3 membranes were prepared by hydrothermal synthesis from a precursor sol containing various amounts of sodium tungstate (Na2WO4) in the presence of tubular substrates with seeds embedded on their outside surface. The seeding method and the amount of Na2WO4 in the precursor sol significantly affected both crystal orientation and densification of the membrane. A precursor sol with appropriate amounts of Na2WO4 was essential to simultaneously satisfy high c-plane orientation and densification of the membrane while excess Na2WO4 drastically decreased the degree of c-plane orientation. A highly c-plane oriented h-WO3 membrane was successfully obtained under the optimized condition, which exhibited a maximum separation factor of 40.0 and a water permeance of 1.53 × 10−7 mol·m−2·s−1·Pa−1 in a 90:10 wt % CH3COOH/water mixture. The water permeance approximately doubled compared to the previous report, possibly owing to the significantly higher degree of c-plane orientation. Furthermore, it was found that its separation ability can be maintained while stored in 90:10 wt % CH3COOH/water mixture with pH < 0 for more than 500 h.

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