4. Process and auxiliary equipment

4.1 Process description

Figure 16 provides an overview of the PEM water electrolysis process by functional block (in English-language literature, everything other than the stack is referred to as the "Balance-of-Plant" or BOP):

• the electrochemical reactor itself (stack), as described above;

• the conversion of electrical power that supplies the reactor with direct current/voltage;

• the water purification system that supplies the anodic loop with water of suitable purity;

• the anodic and cathodic fluidic loops that...