Green hydrogen electrolyzer technology development is advancing as Vaisala refractometers are used in a German engineering project to improve the efficiency and durability of alkaline electrolysers.
The project brings together iChemAnalytics GmbH, Dr.-Ing. Max Schlötter GmbH & Co. KG, and WHW Hillebrand to develop a fully automated test bench for electrolyser stacks and evaluate new electrode coatings under different operating conditions.
At the centre of the project is the challenge of accurately monitoring potassium hydroxide (KOH) electrolyte concentration in a highly corrosive environment, where changes in concentration can affect efficiency, cell voltage, ageing and component life.
Green hydrogen electrolyzer technology development and KOH monitoring
Alkaline electrolysers use an electric current to split water into hydrogen and oxygen in a liquid alkaline solution, typically potassium hydroxide. In this project, the electrolyte operates at high concentration, elevated temperatures and pressure, creating demanding conditions for process measurement.
To address this, the engineering team selected inline refractometers from Vaisala to provide real-time KOH concentration measurements on both sides of the membrane within the test bench.
According to the project team, laboratory analysis was ruled out because it would not provide results quickly enough for process control. The inline approach enables continuous measurement during operation, helping the researchers assess performance in real time.
Vaisala technology supports electrolyser efficiency and durability testing
The test bench is designed to support several objectives, including the development of a fully automated electrolyser test system, the evaluation of new electrode coatings, and the assessment of long-term operational stability.
Engineers are using the system to conduct accelerated stress testing under a range of conditions, including different temperatures and electrolyte behaviours, in order to improve component performance and extend operating life.
Vaisala said its refractometers were selected because they could withstand aggressive KOH conditions while delivering continuous inline measurement, supporting tighter process control and more reliable optimisation of the electrolyser system.
Industry context: improving performance in green hydrogen systems
Green hydrogen is widely seen as an important option for decarbonising sectors that are difficult to electrify directly, but scaling production depends on improving electrolyser efficiency, reliability and cost.
In alkaline electrolysis, process control and materials performance are closely linked. Accurate monitoring of electrolyte concentration can help reduce degradation, improve operating efficiency and support the development of longer-lasting system components.
Within this context, green hydrogen electrolyzer technology development increasingly depends on measurement and control technologies that can operate reliably in harsh chemical environments.
For more coverage, visit our Energy section.
