Bipolar membrane polarization behavior with systematically varied interfacial areas in the junction region

2021 ◽  
Author(s):  
Subarna Kole ◽  
Gokul Venugopalan ◽  
Deepra Bhattacharya ◽  
Le Zhang ◽  
John Cheng ◽  
...  
Keyword(s):  
Electric Field ◽  
Water Dissociation ◽  
Bipolar Membrane ◽  
Junction Region ◽  
Bipolar Membranes ◽  
Membrane Polarization ◽  
Interfacial Areas ◽  
Left Image ◽  
The Right ◽  
The Relationship

Left image is the relationship for the overpotential for water dissociation as a function of bipolar junction electric field whereas the right image presents micrographs and the procedure to make bipolar membranes with micropatterned interfaces.

Bipolar Membranes with Systematically Varied Interfacial Areas in the Junction Region

2021 ◽  
Vol MA2021-01 (45) ◽  
pp. 1826-1826
Author(s):  
Subarna Kole ◽  
Christopher G. Arges
Keyword(s):  
Junction Region ◽  
Bipolar Membranes ◽  
Interfacial Areas

Effect of added salt and increase in ionic strength on skim milk electroacidification performances

2001 ◽  
Vol 68 (2) ◽  
pp. 237-250 ◽  
Author(s):  
LAURENT BAZINET ◽  
DENIS IPPERSIEL ◽  
CHRISTINE GENDRON ◽  
BEHZAD MAHDAVI ◽  
JEAN AMIOT ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Protein Profile ◽  
Skim Milk ◽  
Operation Time ◽  
Water Dissociation ◽  
Bipolar Membrane ◽  
Cathode Voltage ◽  
Experimental Conditions ◽  
Bipolar Membranes ◽  
Added Salt

Bipolar-membrane electroacidification (BMEA) technology, which uses the property of bipolar membranes to split water and the demineralization action of cation-exchange membranes (CEM), was tested for the production of acid casein. BMEA has numerous advantages in comparison with conventional isoelectric precipitation processes of proteins used in the dairy industry. BMEA uses electricity to generate the desired ionic species to acidify the treated solutions. The process can be precisely controlled, as electro-acidification rate is regulated by the effective current density in the cell. Water dissociation at the bipolar membrane interface is continuous and avoids local excess of acid. In-situ generation of dangerous chemicals (acids and bases) reduces the risks associated with the handling, transportation, use and elimination of these products. The aim of this study was to evaluate the performance of BMEA in different conditions of added ionic strength (μadded = 0, 0·25, 0·5 and 1·0 M) and added salt (CaCl2, NaCl and KCl).The combination of KCl and μadded = 0·5 M gave the best results with a 45% decrease in energy consumption. The increased energy efficiency was the result of a decrease in the anode/cathode voltage difference. This was due to an increase of conductivity, produced by addition of salt, necessary to compensate for the lack of sufficiently mobile ions in the skim milk. However, the addition of salts, irrespective of type or ionic strength, increased the required operation time. The protein profile of isolates were similar under all experimental conditions, except at 1·0 M-CaCl2.

scholarly journals Impacts of Flow Rate and Pulsed Electric Field Current Mode on Protein Fouling Formation during Bipolar Membrane Electroacidification of Skim Milk

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 200
Author(s):  
Vladlen S. Nichka ◽  
Thibaud R. Geoffroy ◽  
Victor Nikonenko ◽  
Laurent Bazinet
Keyword(s):  
Reynolds Number ◽  
Electric Field ◽  
Flow Rate ◽  
Skim Milk ◽  
Current Mode ◽  
Pulsed Electric Field ◽  
Bipolar Membrane ◽  
Solution Flow ◽  
Bipolar Membranes ◽  
Protein Fouling

Fouling is one of the major problems in electrodialysis. The aim of the present work was to investigate the effect of five different solution flow rates (corresponding to Reynolds numbers of 162, 242, 323, 404 and 485) combined with the use of pulsed electric field (PEF) current mode on protein fouling of bipolar membrane (BPM) during electrodialysis with bipolar membranes (EDBM) of skim milk. The application of PEF prevented the fouling formation by proteins on the cationic interface of the BPM almost completely, regardless of the flow rate or Reynolds number. Indeed, under PEF mode of current the weight of protein fouling was negligible in comparison with CC current mode (0.07 ± 0.08 mg/cm2 versus 5.56 ± 2.40 mg/cm2). When a continuous current (CC) mode was applied, Reynolds number equals or higher than 323 corresponded to a minimal value of protein fouling of BPM. This positive effect of both increasing the flow rate and using PEF is due to the facts that during pauses, the solution flow flushes the accumulated protein from the membrane while in the same time there is a decrease in concentration polarization (CP) and consequently decrease in H+ generation at the cationic interface of the BPM, minimizing fouling formation and accumulation.

scholarly journals Fouling Mitigation by Optimizing Flow Rate and Pulsed Electric Field during Bipolar Membrane Electroacidification of Caseinate Solution

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 534
Author(s):  
Vladlen S. Nichka ◽  
Victor V. Nikonenko ◽  
Laurent Bazinet
Keyword(s):  
Electric Field ◽  
Flow Rate ◽  
Current Density ◽  
Pulsed Electric Field ◽  
Pause Duration ◽  
High Flow ◽  
Constant Current ◽  
Bipolar Membrane ◽  
Bipolar Membranes ◽  
Protein Fouling

The efficiency of separation processes using ion exchange membranes (IEMs), especially in the food industry, is significantly limited by the fouling phenomenon, which is the process of the attachment and growth of certain species on the surface and inside the membrane. Pulsed electric field (PEF) mode, which consists in the application of constant current density pulses during a fixed time (Ton) alternated with pause lapses (Toff), has a positive antifouling impact. The aim of this study was to investigate the combined effect of three different relatively high flow rates of feed solution (corresponding to Reynolds numbers of 187, 374 and 560) and various pulse–pause ratios of PEF current regime on protein fouling kinetics during electrodialysis with bipolar membranes (EDBM) of a model caseinate solution. Four different pulse/pause regimes (with Ton/Toff ratios equal to 10 s/10 s, 10 s/20 s, 10 s/33 s and 10 s/50 s) during electrodialysis (ED) treatment were evaluated at a current density of 5 mA/cm2. It was found that increasing the pause duration and caseinate solution flow rate had a positive impact on the minimization of protein fouling occurring on the cationic surface of the bipolar membrane (BPM) during the EDBM. Both a long pause and high flow rate contribute to a more effective decrease in the concentration of protons and caseinate anions at the BPM surface: a very good membrane performance was achieved with 50 s of pause duration of PEF and a flow rate corresponding to Re = 374. A further increase in PEF pause duration (above 50 s) or flow rate (above Re = 374) did not lead to a significant decrease in the amount of fouling.

scholarly journals Low-waste fermentation-derived organic acid production by bipolar membrane electrodialysis—an overview

2021 ◽  
Author(s):  
Éva Hülber-Beyer ◽  
Katalin Bélafi-Bakó ◽  
Nándor Nemestóthy
Keyword(s):  
Organic Acid ◽  
Acid Production ◽  
Free Acid ◽  
Raw Materials ◽  
Fermentation Broth ◽  
Water Dissociation ◽  
Bipolar Membrane ◽  
Organic Acid Production ◽  
Bipolar Membranes ◽  
Bipolar Membrane Electrodialysis

AbstractOrganic acids, e.g, citric acid, fumaric acid, lactic acid, malic acid, pyruvic acid and succinic acid, have important role in the food industry and are potential raw materials for the sustainable chemical industry. Their fermentative production based on renewable raw materials requires innovatively designed downstream processing to maintain low environmental impact and resource efficiency throughout the production process. The application of bipolar membranes offers clean and effective way to generate hydrogen ions required for free acid production from its salt. The water dissociation reaction inside the bipolar membrane triggered by electric field plays key role in providing hydrogen ion for the replacement of the cations in organic acid salts. Combined with monopolar ion-exchange membranes in a bipolar membrane electrodialysis process, material flow can be separated beside the product stream into additional reusable streams, thus minimizing the waste generation. This paper focuses on bipolar membrane electrodialysis applied for organic acid recovery from fermentation broth.

scholarly journals Bipolar Membrane and Water Splitting in Electrodialysis

2021 ◽  
Author(s):  
Ireneusz Miesiac ◽  
Beata Rukowicz
Keyword(s):  
Current Flow ◽  
Electrode Reaction ◽  
Dissociation Rate ◽  
Water Dissociation ◽  
Bipolar Membrane ◽  
Water Conductivity ◽  
Electron Hole ◽  
Bipolar Membranes ◽  
Side Process ◽  
Mobility Of Ions

AbstractThe traditional view of the conductivity of electrolytes is based on the mobility of ions in an electric field. A new concept of water conductivity introduces an electron–hole mechanism known from semiconductor theory. The electrolyte ions in the hydrogen bond network of water imitate the structure of a doped silicon lattice. The source of the current carriers is the electrode reaction generating H+ and OH− ions. The continuity of current flow is provided through the electron–hole mechanism, and the movement of electrolyte ions is only a side process. Bipolar membrane in the semiconductor approach is an electrochemical diode forward biased. Generation of large amounts of H+ and OH− has to be considered as a result of current flow and does not require any increase in the water dissociation rate. Bipolar membranes are essential in electrodialysis stacks for the recovery of acids and bases by salt splitting. Graphic Abstract

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