Electrolysis

Electrolysis is the process of using electricity to split water into hydrogen and oxygen. This reaction takes place in a unit called an electrolyser. Our electrolysers can range in size from small, appliance-size equipment that is well-suited for small-scale distributed hydrogen production to large-scale, central production facilities that could be tied directly to our renewable or other non-greenhouse-gas-emitting forms of electricity production. Like fuel cells, electrolysers consist of an anode and a cathode separated by an electrolyte. Different electrolysers function in different ways, mainly due to the different types of electrolyte material involved and the ionic species it conducts.

In a polymer electrolyte membrane (PEM) (Or the Proton Exchange Membrane electrolyser) electrolyser, the electrolyte is a solid specialty plastic material.

• Water reacts at the anode to form oxygen and positively charged hydrogen ions (protons).
• The electrons flow through an external circuit and the hydrogen ions selectively moves across the PEM to the cathode.
• At the cathode, hydrogen ions combine with electrons from the external circuit to form hydrogen gas.

Anode Reaction: 2 H2O → O2 + 4H+ + 4e-

Cathode Reaction: 4 H+ + 4e- → 2 H2

Our PEM systems provide fast response times and production flexibility making it ideal for hydrogen generation utilizing renewable power sources. With minimal maintenance and siting requirements, these electrolysers can produce up to 4,000 Nm3/h of hydrogen gas at 99.9998% purity on-demand. Featuring a scalable modular design that can be containerized (0.27 - 492 Nm³/h), these systems offer solutions that are well-suited for a variety of industrial, fuelling, and renewable energy applications.

Alkaline water electrolysis uses a sodium or potassium hydroxide carrier liquid for the process.

• At the cathode, water molecules are reduced by electrons to hydrogen and negatively charged hydroxide ions.
• At the anode, hydroxide ions are oxidized to oxygen and water while releasing electrons. Overall, a water molecule reacts to hydrogen and oxygen in the ratio of 2:1.

Cathode Reaction: 2 H2O (l)+2e−→H2 (g)+2 OH− (aq)

Anode Reaction: 2 OH− (aq) →0.5 O2(g) + H2O (l) + 2e−

Overall reaction: H2O (l)→H2 (g) + 0.5O2 (g)