Electrodialysis in dairy

What does electrodialysis do

• Ash decrease
• Adjustment of acidity
• Standardization of organoleptic properties
• Improvement of sensory properties; especially taste of acid whey
• Increase the competitiveness of the product
• Generates additional profit
• Lower ecological burden of the production cycle

Main advantages of Electrodialysis by MEGA

• D50, D70 and D90+ demineralization level reached only by ED
• Batch mode
• Design flexibility
• The EWDU units are manufactured in compliance with strict hygienic standards
• Reversibility of the whole ED unit
• Low processing temperature 8 – 15 °C
• Fully automatic process including CIP
• Service 24/7 and remote control

MEGA´s electrodialysis technology for use in the dairy industry

Electrodialyser (ED module/stack) is the main functional component in which the electrodialysis process runs. It simply transports all charged components (minerals, acids etc.) from the diluate loop to the concentrate loop. It is all driven by DC current.

MEGA manufactures electrodialysis reversal modules, which are used for demineralization of various types of liquid solutions.

What is electrodialysis

Electrodialysis (ED) is an electrochemical separation process that uses electrical power (DC voltage) to transfer dissociated ions (cations or anions) and other charged compounds through ion selective membranes and forming two different loops – desalinated loop (diluate) and concentrated loop (brine).

Anion and cation exchange membranes are arranged alternately in parallel between the anode and cathode (see the schematic diagram on the left).

Each type of membrane is permeable to only one type of ion depending on the charge (+ or -) allowing both types of ions to be removed/ transferred.

What is the electrodialysis reversal

The electrodialysis reversal (EDR) is a type of process when the DC polarity and concentrate and dilute loops (circuit) are periodically reversed (switched) which results in continuous self-cleaning. Thanks to the self-cleaning process the membranes have a much longer lifetime.

Minerals removed from the feed are transferred into the concentrate circuit and accumulated in the concentrate tank which is continuously diluted by soft water to prevent it from precipitation of minerals and to keep the required conductivity. pH is automatically controlled as well.

Batch system

At least two tanks are required. However, the recommended number is three. The system works the following way:

Pre-concentrated by-products are pumped from the first tank to the Feed/Diluate loop (circuit) of the EWDU unit to be processed and to achieve required demineralization rate.

When the product in the first tank (first batch) reaches the required demineralization rate, the unit switches automatically to the second tank. After the first batch is discharged, the tank is ready to be cleaned and again filled with a new pre-concentrated by-product. The first desalinated batch should be discharged. That’s why three tanks are better: the first one for the demineralization process; the second one for CIP and the last one for the new raw product, that is ready to be demineralized.