Hydrogen in Elektrolysis

Process description

Hydrogen can be produced in large quantities by electrolysis without CO₂ using energy from renewable sources.

In large-scale production, ordinary demineralized water is split into oxygen and hydrogen by means of electric current in an electrolyzer.

Commercial water electrolysis systems for industrial use are currently designed as alkaline electrolysis with the electrolyte potassium hydroxide or as membrane electrolysis "Proton Exchange Membrane (PEM) Electrolysis" with a proton conducting polymer membrane. In alkaline electrolysis, valves are also used to handle the aqueous electrolyte solution.

Currently, electrolysis plants are largely operated at atmospheric pressure. In principle, increasing the operating pressure has the advantage that the hydrogen produced at high pressure does not have to be recompressed as much for storage purposes, which results in potential energy savings.

Requirements

• Alkaline electrolysis at approx. 90°C and an operating pressure between atmospheric and 120 bar (commercially up to approx. 30 bar).

• Membrane electrolysis at approx. 90°C and an operating pressure of 350 bar.

• High requirement for tightness - gas tightness at high pressures.

• Safety of the valve.

• High demands on pressure-bearing materials to avoid hydrogen-induced stress corrosion cracking.

• Long service life even at high pressures.

Solutions

The electrolysis processes for hydrogen production, including water treatment, cooling, hydrogen purification and the generation of high-purity hydrogen, require reliable and safe valves from KLINGER Schöneberg.

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