scholarly journals Pervaporation dehydration of ethanol-water mixture using crosslinked poly(vinyl alcohol) membranes

2016 ◽  
Vol 19 (4) ◽  
pp. 97-106
Author(s):  
Hai Le Tran ◽  
Minh Ngoc Duy Vuu ◽  
Quan Minh Hoang ◽  
Nguyen Thi Nguyen ◽  
Phong Thanh Mai

Crosslinked poly(vinyl alcohol) (PVA) composite membranes were synthesized by casting selective crosslinked PVA films on the polyacrylonitrile (PAN) porous substrates. The PVA films were prepared by in-situ crosslinking technique using four different crosslinking agents, such as glutaraldehyde, fumaric acid, maleic acid and malic acid. The separation performance in terms of permeation flux and separation factor of prepared membranes were evaluated for pervaporation dehydration of ethanol/water mixture of 80/20 wt% at 60 oC. The prepared membranes were also characterized by FTIR, SEM, swelling and sessile drop contact angle measurements. It was found that the chemical structure of the PVA membrane was changed via crosslinking reaction. The physicochemical properties (hydrophilicity and swelling degree) and separation performance of the prepared membranes were affected by the chemical structures of the crosslinking agents. Furthermore, there was a trade-off between permeation flux and selectivity of the resulting membranes. When the flux increased, the separation factor decreased. The results of this study contributed to enrich the data of the crosslinking reaction of PVA membranes, and expected to help researcher in suitable choosing crosslinking agent for producing pervaporation PVA membrane for dehydration of ethanol solutions.

2011 ◽  
Vol 287-290 ◽  
pp. 2053-2056
Author(s):  
Zhen Huang ◽  
Wei Juan Jiang ◽  
Xiao Han Shi ◽  
Li Jun Teng

Three-layered zeolite LTA-filled poly (vinyl alcohol) (PVA) composite membranes have been fabricated for water removal from highly concentrated ethanol solution by means of pervaporation. Higher separation factor and higher fluxes are both achieved after adding zeolite 3A, 4A and 5A. Through evaluating separation factor and permeation flux, separation performances of the composite membranes are elucidated in terms of the zeolite pore size and processing temperature.


2011 ◽  
Vol 239-242 ◽  
pp. 1331-1334
Author(s):  
Zhen Huang ◽  
Yu Hua Guo ◽  
Gui Mei Guo ◽  
Li Jun Teng

Pervaporation performances of three –layer zeolite-filled poly (vinyl alcohol) composite membranes have been investigated for ethanol dehydration. Compared the neat polymer counterparts, high separation factor and high fluxes are both achieved by these membranes, indicating that ethanol/water separation is enhanced with the zeolites. Zeolites used include 3A, 4A, 5A, NaX, NaY, silicalite-1 and Beta. Through evaluating separation factor, ethanol flux and total pervaporation flux, separation performances of composite membranes are elucidated in detail in terms of the zeolite pore size, its hydrophilic/hydrophobic nature as well as its crystal framework.


2011 ◽  
Vol 675-677 ◽  
pp. 383-386 ◽  
Author(s):  
Lu Bai ◽  
Ping Qu ◽  
Shuai Li ◽  
Yuan Gao ◽  
Li Ping Zhang

In this study, pervaporation membranes were prepared from poly( vinyl alcohol) (PVA) with different amounts of cellulose nanocrystals as filler, and characterized by scanning electron microscopy (SEM). The characterization results demonstrated that cellulose nanocrystal particles dispersed homogeneously within the PVA matrix. Moreover, the pervaporation performance of these membranes was investigated using the separation of ethanol-water mixture as model system. Among all the prepared membranes, PVA/cellulose nanocomposite membrane containing 1 wt% cellulose nanocrystals exhibited the best pervaporation performance, whose averaged permeation flux reduced slightly but separation factor was increased from 83 to 163 for 80% aqueous solution of ethanol at 80 °C respectively.


2011 ◽  
Vol 63 (8) ◽  
pp. 1695-1700 ◽  
Author(s):  
J. H. Lv ◽  
G. M. Xiao

Cellulose acetate/ polyacrylonitrile (CA/PAN) membranes were prepared and used to separate pyridine / water mixtures by pervaporation. The membranes were characterized through SEM. The effects of feed concentration, operation temperature and downstream pressure on the separation performance were evaluated. Experimental results indicated the increase of operation temperature could raise the permeation flux and the separation factor, while increasing feed concentration and downstream pressure would raise the separation factor and decrease the permeation flux. Under the conditions that pyridine solution was 99 wt.%, operation temperature was 323 K and downstream pressure was 20 mmHg, the CA/PAN blend membrane showed its best separation performance that the permeation flux was 56 · g · m−2 h−1 and the separation factor was 182.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bedriye Ucpinar Durmaz ◽  
Ayse Aytac

Abstract Bio-based films containing poly (vinyl alcohol)/casein have poor mechanical and water vapor barrier properties that limit their use in packaging application. Some properties such as water resistance and tensile strength can be increased by the cross-linking process. For this reason, poly(vinyl alcohol)/sodium caseinate (PVA/SC) blends were crosslinked by adding glutaraldehyde (GLA) and glyoxal (GL) at different ratios in this work. The films were prepared by solution casting technique. Fourier transform infrared analysis (FTIR) confirmed the crosslinking reaction between the components. As a result of the crosslinking, the thicknesses, water vapor barrier properties and water contact angle values of the films have increased. The total soluble matters (TSM) of PVA/SC film decreased with increasing amounts of crosslinkers and GLA crosslinked films exhibited lower TSM. The addition of GLA and GL resulted in more strengthened films as verified by the tensile test. On the other hand, GLA crosslinked films were more flexible than un-crosslinked and GL crosslinked PVA/SC films. The hydrophilic PVA/SC film became more hydrophobic with the increasing amounts of crosslinkers. With the crosslinking, the PVA/SC film became more thermally stable. In conclusion, the crosslinked PVA/SC films were obtained with suitable properties for packaging applications.


2013 ◽  
Vol 807-809 ◽  
pp. 591-595
Author(s):  
Hong Liang Chen ◽  
Ji Song Yang ◽  
Yan Wang ◽  
Hui Ying Li ◽  
Xin Xin Li ◽  
...  

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.


2018 ◽  
Vol 16 (2) ◽  
pp. 144 ◽  
Author(s):  
Retno Ariadi Lusiana ◽  
Dwi Siswanta ◽  
Mudasir Mudasir

Preparation of membrane using crosslinking reaction between chitosan and citric acid showed that functional group modification increased the number of active carrier groups which lead to better transport capacity of the membrane. In addition, the substitution of the carboxyl group increased creatinine permeation of chitosan membrane. The transport capacity of citric acid crosslinked chitosan membrane for creatinine was found to be 6.3 mg/L. The presence of cyanocobalamin slightly hindered the transport of creatinine although compounds did not able to pass through citric acid crosslinked chitosan/poly(vinyl alcohol) blend membrane, as compounds no found in the acceptor phase.


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