Mechanical Engineering Wiki / Electrolyzer
Electrolyzer
An electrolyser is a technical system that uses electricity to split water (H₂O) into its components hydrogen (H₂) and oxygen (O₂) - a process known as electrolysis. This key technology is essential for the production of green hydrogen, provided the electricity used comes from renewable sources.
How it works at a glance:
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Anode (positive pole): Oxygen is produced here. Electrons are removed from the water molecule.
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Cathode (negative pole): Hydrogen is produced here. Electrons are added.
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Electrolyte: Conducts the ions between the anode and cathode without the gases mixing.
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Power source: Supplies the direct current required for electrolysis.
The gases produced are then separated from the system and can be used in a variety of ways - hydrogen, for example, as a climate-neutral energy source in industry, mobility or for the intermediate storage of renewable energy.
Relevance for smart mechanical engineering:
In modern manufacturing, the electrolyzer plays a central role in sustainable production processes and the transformation towards low-CO₂ industries. Smart mechanical engineering companies such as MackSmaTec are helping to integrate this technology into industrial value chains with modular, scalable systems.
In-depth technical analysis of electrolysis processes
In order to understand the efficiency and scalability of electrolysers on an industrial scale, it is necessary to differentiate between the three dominant cell architectures. Each of these technologies has specific material science and thermal management requirements.
1. proton exchange membrane (PEM) electrolysis
PEM electrolysis is considered the most dynamic solution for smart mechanical engineering, as it can react extremely quickly to load changes (typical for wind and solar energy).
- Electrochemical process: Water is split into oxygen, electrons and protons (H⁺) at the anode. The proton-conducting polymer membrane only allows the protons to diffuse to the cathode, where they recombine to form H₂.
- Special technical feature: The solid membrane eliminates the need for a liquid electrolyte, which enables a very compact design and high power densities.
- Challenge: Due to the acidic environment, expensive precious metals such as iridium (anode) and platinum (cathode) must be used as catalysts.
2. alkaline electrolysis (AEL)
AEL is the most technologically mature and cost-effective variant that has been used on an industrial scale for decades.
- Electrolyte: A highly concentrated potassium hydroxide solution (KOH, approx. 20-30 %) is used here. A porous diaphragm separates the gas spaces.
- Advantage: Inexpensive materials such as nickel can be used for the electrodes, as the alkaline environment is less corrosive to non-precious metals.
3. high-temperature electrolysis (SOEC)
This technology operates at temperatures between 700 °C and 900 °C and offers the highest efficiency potential.
- Thermodynamics: As part of the energy is supplied as heat (steam), the need for electrical work is reduced. This leads to electrical efficiencies of over 85 %.
- Reversibility: SOEC cells can often be operated bidirectionally (generation of H₂ or reconversion to electricity).
Technical comparison of the systems
| Parameters | PEM | Alkaline (AEL) | High temperature (SOEC) |
|---|---|---|---|
| Operating temperature | 50 - 80 °C | 60 - 90 °C | 700 - 900 °C |
| Catalyst | Iridium / platinum | Nickel / steel | Ceramic oxides |
| System efficiency | ~ 65 - 75 % | ~ 60 - 70 % | > 85 % |
The smart approach: modularity and Power-to-X
The technical depth in modern mechanical engineering today lies in the Balance of Plant (BoP). This includes high-precision power electronics, efficient thermal management to extend the service life of membranes and integrated sensor technology for predictive maintenance. Modular systems allow these technologies to be precisely integrated into existing industrial value chains.