Hydrogen production from water electrolysis is an effective choice for hydrogen production from renewable resources

 

Hydrogen production from water electrolysis is a promising choice for hydrogen production from renewable resources. Hydrogen production from water electrolysis is a process in which water is decomposed into hydrogen and oxygen by electricity.
 
The reaction takes place in a unit called an electrolyzer. Water electrolysis hydrogen production equipment has a wide range of sizes, from small equipment which is very suitable for small distributed hydrogen production to large centralized production facilities which can be directly linked with renewable energy or other non greenhouse gas emissions.
 
How does it work?
Like fuel cells, water electrolyzers consist of anodes and cathodes separated by electrolytes. The function of different electrolyzers is slightly different, which is mainly due to the different types of electrolyte materials used
 
Polymer electrolyte membrane electrolyzer
In polymer electrolyte membrane (PEM) electrolyzer, electrolyte is a kind of solid special plastic material.
 
Water reacts at the anode to form oxygen and positively charged hydrogen ions (protons).
 
The electrons flow through the external circuit, and the hydrogen ion selectively passes through the PEM to the cathode.
 
At the cathode, hydrogen ions combine with electrons from an external circuit to form hydrogen. Anodic reaction: 2h 2O → Ò 2 + 4H + + 4E medium cathode reaction: 4H + + 4E medium - → 2H 2
 
Alkaline electrolyzer
The alkaline electrolyzer is operated by the transport of hydroxyl ions (OH - generated on the cathode side through the electrolyte from the cathode to the anode with hydrogen). Electrolyzers using liquid alkaline solutions of sodium hydroxide or potassium hydroxide as electrolytes have been commercialized for many years. The new method of using solid alkaline exchange membrane as electrolyte shows hope in laboratory scale.