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.

scholarly journals ZSM-5 Filled Polyether Block Amide Membranes for Separating EA from Aqueous Solution by Pervaporation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jin Gu ◽  
Xinran Zhang ◽  
Yunxiang Bai ◽  
Le Yang ◽  
Chunfang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ethyl Acetate ◽  
Separation Factor ◽  
The Other ◽  
Total Flux ◽  
Feed Concentration ◽  
Similar Variation ◽  
Other Hand

ZSM-5 filled polyether block amide membranes (PEBA), PEBA/ZSM-5, were prepared and used to recover aroma, ethyl acetate (EA), from aqueous solution by pervaporation (PV). The membranes demonstrated high EA permselectivity, and with the increase of ZSM-5 loading, the separation factor increased initially and then decreased, while the total flux demonstrated the similar variation until the ZSM-5 loading was 10 wt%, at which it reached the lowest value. After that, it began to increase again. On the other hand, the separation factor, and total flux of the PEBA/ZSM-5 membrane containing 10 wt% ZSM-5, PEBA/ZSM-5-10, increased with the increase of feed concentration and temperature. The best PV performance, separation factor and total flux of PEBA/ZSM-5-10 membrane were 185.5 and 199.5 gm−2h−1, respectively, with feed concentration of 5 wt% EA at 50°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.

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.

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 Performance of a pervaporation system for the separation of an ethanol-water mixture using fractional condensation

2018 ◽  
Vol 77 (7) ◽  
pp. 1861-1869 ◽  
Author(s):  
Jie Liu ◽  
Jiding Li ◽  
Quan Chen ◽  
Xiaoduan Li
Keyword(s):  
Flow Velocity ◽  
Separation Factor ◽  
Polyvinylidene Fluoride ◽  
Separation Efficiency ◽  
Composite Membranes ◽  
Total Flux ◽  
Water Mixture ◽  
Term Operation ◽  
Fractional Condensation ◽  
Feed Temperature

Abstract Polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) composite membranes were fabricated and subsequently applied in ethanol recovery from an ethanol-water mixture by pervaporation (PV) using fractional condensation. The effects of feed temperature and feed flow velocity on the pervaporative properties of PDMS/PVDF composite membranes were investigated. Scanning electron microscopy (SEM) results showed that PDMS was coated uniformly on the surface of porous PVDF substrate, and the PDMS separation layer was dense with a thickness of 1.7 µm. Additionally, it was found that with increasing feed temperature, the total flux of the composite membrane increased, whereas the separation factor decreased. As the feed flow velocity increased, the total flux and separation factor increased. Besides, the permeate vapor was condensed by a two-stage fractional condenser maintained at different temperatures. The effects of the condensation conditions on fractions of ethanol-water vapor were studied to concentrate ethanol in product. The fractional condensers proved to be an effective way to enhance the separation efficiency. Under the optimum fractional condensation conditions, the second condenser showed a flux of 1,329 g/m2 h and the separation factor was increased to 17.2. Furthermore, the long-term operation stability was verified, indicating that the PV system incorporating fractional condensation was a promising approach to separate ethanol from the ethanol-water mixture.

scholarly journals A Novel Quantitative Prediction Approach for Pungency Level of Chinese Liquor (Baijiu) Based on Infrared Thermal Imager

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1107
Author(s):  
Yingxia He ◽  
Shuang Chen ◽  
Ke Tang ◽  
Yan Xu ◽  
Xiaowei Yu
Keyword(s):  
Aqueous Solution ◽  
Surface Temperature ◽  
Sensory Analysis ◽  
Alcoholic Beverages ◽  
Quantitative Prediction ◽  
Thermal Imager ◽  
Surface Temperatures ◽  
Tongue Surface ◽  
Ethanol Aqueous Solution ◽  
Prediction Approach

Pungency is a crucial sensory feature that influences consumers’ appreciation and preferences toward alcoholic beverages. However, the quantitation of pungency is challenging to achieve using sensory analysis because of persistence, accumulation, and desensitization to the pungency perception. This study aimed to design a novel pungency evaluation method based on the measurement of tongue surface temperature. An infrared thermal (IRT) imager technique for measuring tongue surface temperature was established. To validate its feasibility, the IRT technique was used to measure tongue surface temperatures after the tongue was stimulated by (1) water and Baijiu, (2) different concentrations of ethanol aqueous solution (10, 20, 30, 40, and 50%, v/v), (3) ethanol aqueous solution and Baijiu samples with the same ethanol content, and (4) 26 Baijiu samples with different pungency level. For all cases, tongue surface temperatures showed large differences as a result of the different stimulation. The results showed that the tongue surface temperature correlated with the pungency intensity obtained by the sensory analysis. The relationship between tongue surface temperature and pungency intensity was established by multiple linear regression analysis. The IRT technique was able to be a useful support tool to quantitatively predict the pungency of alcoholic beverages, based on the measurement of tongue surface temperature.

scholarly journals Double-Cross-Linked Networks Based on Methacryloyl Mucin

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1706
Author(s):  
Elena Olăreț ◽  
Brîndușa Bălănucă ◽  
Andra Mihaela Onaș ◽  
Jana Ghițman ◽  
Horia Iovu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Chemical Modification ◽  
Structural Modification ◽  
Aqueous Media ◽  
Cross Linking ◽  
Ph Values ◽  
Acid Aqueous Solution ◽  
Reaction Media ◽  
Double Cross

Mucin is a glycoprotein with proven potential in the biomaterials field, but its use is still underexploited for such applications. The present work aims to produce a synthesis of methacryloyl mucin single-network (SN) hydrogels and their double-cross-linked-network (DCN) counterparts. Following the synthesis of the mucin methacryloyl derivative, various SN hydrogels are prepared through the photopolymerization of methacrylate bonds, using reaction media with different pH values. The SN hydrogels are converted into DCN systems via supplementary cross-linking in tannic acid aqueous solution. The chemical modification of mucin is described, and the obtained product is characterized; the structural modification of mucin is assessed through FTIR spectroscopy, and the circular dichroism and the isoelectric point of methacryloyl mucin is evaluated. The affinity for aqueous media of both SN and DCN hydrogels is estimated, and the mechanical properties of the systems are assessed, both at macroscale through uniaxial compression and rheology tests and also at microscale through nanoindentation tests.

Novel pH-Sensitive Poly(Vinyl Alcohol) Based Polyampholyte as Pervaporation Membrane

2016 ◽  
Vol 852 ◽  
pp. 979-983
Author(s):  
Ping Rui Meng ◽  
Liang Bo Li
Keyword(s):  
Aqueous Solution ◽  
Vinyl Alcohol ◽  
Water Resistance ◽  
Graft Copolymerization ◽  
Sodium Acrylate ◽  
Poly Vinyl Alcohol ◽  
Permeate Flux ◽  
Ft Ir ◽  
Ethanol Aqueous Solution ◽  
Poly Acrylamide

Sodium acrylate (NaAA) and acrylamide (AM) were grafted onto poly (vinyl alcohol) (PVA) using potassium persulfate as an initiator, Graft copolymerization namely poly (vinyl alcohol)-g-poly (acrylamide/sodium acrylate) (PVA-g-PAM/SAC). The poly (vinyl alcohol)-g-poly (vinylamine/sodium acrylate) (PVAMC) was prepraed by Hofmann rearrangement.The PVAMC homogeneous membrane was characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM).The water resistance of the PVAMC membranes is the best when pH of the PVAMC solutions was 4, at that time the numbers of-NH3+ and-COO- groups trended to be equal, so the isoelectric point was pH=4. At 90 °C the pervaporation of PVAMC composite membrane was tested and showed that the separation factor and the permeate flux were about 1001 and 1341 g/(m2·h) for 90wt% ethanol aqueous solution, and they were about 1297 and 1040 g/(m2·h) for 90wt% isopropanol aqueous solution.

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