Electrodialysis wine industry

Synthetic membranes with calibrated pores are used for various operations in the wine industry ultrafiltration, front-end microfiltration, tangential microfiltration and reverse osmosis. Electrodialysis and pervaporation, special separation techniques described elsewhere in this book (Section 12.5.1), also make use of membranes. 

The two water desalination applications described above represent the majority of the market for electrodialysis separation systems. A small application exists in softening water, and recently a market has grown in the food industry to desalt whey and to remove tannic acid from wine and citric acid from fruit juice. A number of other applications exist in wastewater treatment, particularly regeneration of waste acids used in metal pickling operations and removal of heavy metals from electroplating rinse waters [11]. These applications rely on the ability of electrodialysis membranes to separate electrolytes from nonelectrolytes and to separate multivalent from univalent ions. 

Food industry and medical supplies Edible salt production from seawater,23 demineralization of whey,24 recovery of amino acids from fermentation liquor,25 separation of amino acids,26 preparation of lactic acid27, gluconic acid28 amino acids,29 etc. from their salts, stabilization of grape juice30 and pre-treatment of wine,31 deacidification of sour orange juice,32 desalination of soups, desalination of soybean sauce,33 continuous fermentation in the presence of electrodialysis,34 de-ionization of sugar solution.35... 

The first indnstrial electrodialysis nnit with a 45 m membrane surface went into operation in 1996. Its resnlts, consistent with those of the many earlier pilot tests, showed that electrodialysis can be applied on an industrial scale for the tartrate stabilization of wine. The optimnm effectiveness of this techniqne is subject to choosing a pair of (anion and cation) membranes that best preserve the wine s natnral balance, and combining it with an antomatic testing system to restrict the treatment to the minimum required to achieve tartrate stability. 

Ultraflltration is also used to fractionate and concentrate proteins from potato processing wastewaters. Other protein wheys can be processed by reverse osmosis. Electrodialysis is used for a number of applications in the food and beverage industry, including deionization or deacidification of fruit juices, wines and, in the dairy industry, milk and whey. It often competes directly with ion exchange processes. 

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