Electrodialysis with bipolar membranes

The energy required for the water dissociation can be calculated from the Nernst equation for a concentration chain between solutions of different pH values. It is given by  

AG is the Gibbs free energy, Fis the Faraday constant, the R is the gas constant, T is the absolute temperature and ApH and A p are the pH value and the voltage difference between the two solutions separated by the bipolar membrane. For 1 mol L 1 acid and base solutions in the two phases separated by the bipolar membrane AG is 0.022 kWh mol and Arp is 0.828 [V] at 25 °C. 

The transport rate of H + and OH ions from the transition region into the outer phases cannot exceed the rate of their generation. However, the generation rate of H + and OH ions in a bipolar membrane is drastically increased compared to the rate obtained in water due to a catalytic reaction [26, 27]. Therefore, very high production rates of acids and bases can be achieved in bipolar membranes. 

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Novalic, S., Okwor, J., and Klaus, D.K. 1996. The characteristic of citric acid separation using electrodialysis with bipolar membranes. Desalination 105, 277-282. 

Quoc, A.L., Lamarche, F., and Makhlouf, J. 2000. Acceleration of pH variation in cloudy apple juice using electrodialysis with bipolar membranes. J. Agric. Food Chem. 48, 2160-2166. 

In this chapter only electromenbrane separation processes such as electrodialysis, electrodialysis with bipolar membranes and continuous electrodeionization will be discussed. 

Figure 5.10 Schematic diagram illustrating the acid and base production from the corresponding salt by electrodialysis with bipolar membranes.

The key element in electrodialysis with bipolar membranes is the bipolar membrane. Its function is illustrated in Figure 5.11(a), which shows a bipolar membrane consisting of an anion- and a cation-exchange layer arranged in parallel between two electrodes. 

Electrodialysis with Bipolar Membrane System and Process Design... 

Electrodialysis with Bipolar Membrane Process Costs... 

Investment costs in electrodialysis with bipolar membranes Investment costs include nondepreciable items such as land and depreciable items such as the electrodialysis stacks, pumps, electrical equipment, and monitoring and control devices. The investment costs are determined mainly by the required membrane area for a certain plant capacity. The required membrane area for a given capacity plant can be calculated from the current density in a stack that is in electrodialysis with a bipolar membrane not limited by concentration-polarization effects. The required membrane area for a given plant capacity is given by ... 

Electrodialysis with bipolar membranes (EDBMs) [23] was applied recently to the production of mineral and organic acids [24-36], inhibition of enzymatic browning [37-39], and separation of protein [40-44]. These applications are based on water dissociation at the interface of a bipolar membrane (BPM) coupled with monopolar membrane action. A recent up-to-date overview gives the possibilities and the economic relevance of BPM technology [45]. 

Principle of Electrodialysis with Bipolar Membrane 21.2.3.1 H" and OH Generation... 

FI CU RE 21.32 (a) Electrodialysis (ED) and (b) electrodialysis with bipolar membrane (EDBM) configurations tested for recovery of magnesium... 

Electrodialysis (ED) Electrodialysis with bipolar membranes (EDBM)... 

Alvarez F, Alvarez R, Coca J, Sandeaux J, Sandeaux R, and Gavach C. Salicylic acid production by electrodialysis with bipolar membranes. J. Membr. Sci. 1997 123 61-69. 

H.P. Rapp, G. Eigenberger and H. Strathmann, Electrodialysis with bipolar membranes - theory and application , Proc. of ICOM 96 The 1996 International Congress on Membranes and Membrane Processes), Yokohama, Aug. 18-23, p. 506-507. 

S. Novalic, J. Okwor and K.D. Kulbe, The characteristics of citric acid separation using electrodialysis with bipolar membranes, Desalination, 1996, 105, 277-282 E Alvarez, R. Alvalez, J. Coca, J. Sandeaux, R. Sandeaux and C. Gavach, Salicylic acid production by electrodialysis with bipolar membranes, J. Membr. Sci., 1997, 123, 61-69. 

Quoc, A.L., Mondor, M., Lamarche, F., Ippersiel, D., Bazinet, L., and Makhloul, J. 2006. Effect of a combination of electrodialysis with bipolar membranes and mild heat treatment on the browning and opalescence stability of cloudy apple juice. Food Res. Int. 39, 755-760. 

Application of conventional electrodialysis and electrodialysis with bipolar membranes in the development of new processes desalination of wastewater from organic synthesis processes to allow recovery and reuse in the system obtention of high value products that can increase their pharmacological activity by substitution of the anions or cations present in natural sources. 

Pourcelly G, Gavach C (2000) Electrodialysis water splitting - application of electrodialysis with bipolar membranes. In Kemperman AJB (ed) Handbook of bipolar membrane technology. Twenty University Press, Enschede... 

Tabaka K, Kimura K, Yamaguchi Y (1969) Process for producing L-glutamic add and a-ketoglutaric add. US Patent 3450599, Kyowa Hakko Kogyo, Tokyo Tongwen X, Weihua Y (2002) Citric acid production by electrodialysis with bipolar membranes. Chem Eng Process 41(6) 519-524... 

Dinculescu D, Guzin-Stoica A, Dobre T, Floarea O (2000) Experimental investigation of citric acid reactive extraction with solvent recycling. Bioprocess Eng 22 529-532 Pinacci P, Radaelli M (2002) Recovery of citric acid from fermentation broths by electrodialysis with bipolar membranes. Desalination 148 177-179... 

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