The Electrolysis System
In water electrolysis, electrical energy is used to split water molecules (H2O) into their components: H2 as the main product and O2 as a by-product.
In addition to the stacks in which the electrochemical process is implemented, the electrolysis system contains all the necessary components and subsystems to guarantee an optimized process. Particular attention is paid to process water treatment, heat management and power supply. The gas treatment completes the system and guarantees the ambitious product qualities. The fully automated and self-protecting system is known as the Balance of Plant (BoP) and is divided into the following components:
1) Power Electronics regulates the voltage level and converts the alternating current into direct current, which is required for the stacks.
2) Purification and Gas Analysis Module removes impurities in the hydrogen stream and analyzes the quality of hydrogen and oxygen to continuously monitor the health of the system.
3) Supply Equipment for a turnkey solution, the compressed air supply for the instrumentation, a chiller, the nitrogen supply for inerting the system, etc. must already be integrated into the system.
4) Thermal Management Module ensures the optimum operating temperature range of the PEM stacks and thus has a major influence on system efficiency.
5) Safety Module ensures safe operation of the system.
Two main electrolyzer technologies are currently used in the industry. The first is alkaline electrolysis (ALK), in which a liquid electrolyte (potassium or sodium hydroxide) is used as the starting material. And secondly, polymer electrolyte membrane electrolyzers (PEM), which are fed with ultrapure water. PEM electrolysis offers the advantage of a high-purity process gas and flexible operation. PEM electrolyzers are therefore particularly preferred in connection with volatile, renewable energy systems.
In the context of the EU's decarbonization targets, on-site production of
