What are Electrolysers?

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About Electrolysers

It is an apparatus that produces hydrogen through a chemical process (electrolysis) capable of splitting water molecules into hydrogen and oxygen molecules by using electricity.

Working

An electrolyser consists of a conductive electrode stack separated by a membrane to which a high voltage and current is applied.
This causes an electric current in the water which causes it to break down into its components: hydrogen and oxygen.
The oxygen generated in parallel is released into the atmosphere or can be stored for later use as a medical or industrial gas in some cases.
The hydrogen is stored as a compressed gas or liquefied for use in industry or in hydrogen fuel cells, which can power transport vehicles such as trains, ships and even aircraft.

Types of Electrolysers

Alkaline electrolysers: Alkaline electrolysis is a mature and commercially available technology used primarily by the fertiliser and chlorine industries.
It presently accounts for almost two-thirds of the global electrolyser capacity.
It uses thick membranes and nickel-based electrodes.
Proton exchange membrane (PEM) electrolysers: It operates at high pressure, due to the use of thin perfluorosulfonic acid (PFSA) membranes.
However, the PFSA acidic environment makes it necessary to use gold and titanium plated electrodes and metals such as platinum, iridium, and ruthenium as catalysts.
They are the most popular because they produce high-purity hydrogen and are easy to cool.
Solid oxide electrolysis cell (SOEC) electrolysers : They utilise heat to make hydrogen from steam and are best placed where there is a heat source available (nuclear or industrial facilities).
They operate at high temperatures (500 – 850degrees).
Anion exchange membrane (AEM) electrolysers: They operate at significantly lower temperatures of 50 – 60 degrees.
They combine the less harsh conditions of alkaline electrolysers with the simplicity and high efficiency of PEM electrolysers.

Q1: What is hydrogen?

It is a clean alternative to methane, also known as natural gas. It’s the most abundant chemical element, estimated to contribute 75% of the mass of the universe.

Source:Domestic manufacturing of electrolysers can be game changer for industrial emissions