make-up water for sodium hydroxide and chlorine production electrolytic systems

Reading time:

Membrane cells develop current densities of up to 7 000 A·m–2 and, therefore, require very advanced qualities from the NaCℓ brine they receive, resulting in the following treatments :

  • sulphate removal by precipitating BaSO4 in Densadeg (injecting BaCO3 or Ba Cℓ2);
  • removing traces of Ca2+ from specific softening resins (down to below 50 mg · L–1 Ca2+);
  • vacuum dechlorination, often in sidestream mode and, if necessary, supplemented with bisulphite (figure 25).
Chemical purification brine electrolysis membrane cell - Aracruz plant Secured image
Figure 25. Chemical purification of brine for electrolysis using membrane cells. Schematic diagram of the Aracruz plant (Brazil)

Bookmark tool

Click on the bookmark tool, highlight the last read paragraph to continue your reading later