Lactic Acid and Salt Separation Using Membrane Technology

Membranes, vol. 11, pp. 107

Abstract

Acid whey is a by-product of cheese and yoghurt manufacture. The protein and lactose within acid whey can be recovered using nanofiltration and electrodialysis, but this leaves a waste stream that is a mixture of salts and lactic acid. To further add value to the acid whey treatment process, the possibility of recovering this lactic acid was investigated using either low energy reverse osmosis membranes or an electrodialysis process. Partial separation between lactic acid and potassium chloride was achieved at low applied pressures and feed pH in the reverse osmosis process, as a greater permeation of potassium chloride was observed under these conditions. Furthermore, lactic acid retention was enhanced by operating at lower temperature. Partial separation between lactic acid and potassium chloride was also achieved in the electrodialysis process. However, the observed losses in lactic acid increased with the addition of sodium chloride to the feed solution. This indicates that the separation becomes more challenging as the complexity of the feed solution increases. Neither process was able to achieve sufficient separation to avoid the use of further purification processes.

Authors 5

1. Sahar Talebi

   The University of Melbourne

   Affiliation as printed

   The ARC Dairy Innovation Hub, Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia

2. Michael Garthe Aachen Chemical Process Engineering

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering, RWTH University, Forckenbeckstraße 51, 52074 Aachen, Germany

3. Florian Roghmans Aachen Chemical Process Engineering

   RWTH Aachen University

   Affiliation as printed

   Chemical Process Engineering, RWTH University, Forckenbeckstraße 51, 52074 Aachen, Germany

4. George Q. Chen

   The University of Melbourne

   Affiliation as printed

   The ARC Dairy Innovation Hub, Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia

5. Sandra Elizabeth Kentish corresponding

   The University of Melbourne

   Affiliation as printed

   The ARC Dairy Innovation Hub, Department of Chemical Engineering, University of Melbourne, Parkville, VIC 3010, Australia