Uhde Chlorine Engineers (Italia) Srl

Liquid HCI Electrolysis with Gas Diffusion Electrodes Technology

Chlorine is used as an oxidizing agent in several organic processes and gaseous HCl is often released as a by-product. It is not always possible to find an use for the acid and the discharge to waste treatment is not a satisfactory solution.

The recover of chlorine from hydrochloric acid has several advantages:

  • No costs related to hydrochloric acid disposal.
  • Business is made independent from Cl2 and HCl prices.
  • Reduced investment versus the installation of a traditional chlor-alkali plant of the same capacity
  • Interesting for regions with high Cl2 demand or excess caustic soda.

Gas Diffusion Electrode based electrolysis

ThyssenKrupp Uhde Chlorine Engineers (Italia) S.r.l. HCl membrane electrolyzers are based on the application of Gas Diffusion Electrode technology, also known as Oxygen Depolarized Cathode (ODC), to the electrolysis process. This innovative technology has been developed and industrialized with its Partners Bayer MaterialScience AG, Bayer Technology Services GmbH and De Nora Noth America. The principle consists in the oxygen reaction with the hydrogen ions that migrate through the membrane at the cathode side of the cell, resulting in an operating voltage lower than approx 1 V versus the standard reaction of hydrogen evolution, and the consequent energy savings.

Technology highlights

  • Metallic electrolyzers for robustness and durability.
  • High reliability.
  • Easy to start/operate (operational flexibility).
  • Power consumption around 1100-1200 kWh/t Cl2 (at 5 kA/m2).
  • Quality of product (99.9% Cl2).
  • Industrially proven.

Figure 1
215.000 KTPY Cl2
Caojing - Shanghai

All pictures courtesy of Bayer MaterialScience.