A new alkaline electrolyser plant could not consistently reach fuel-cell grade purity because KOH aerosol carryover exceeded what the downstream dryer could handle.
- ISO 14687 purity achieved
- Grade D
- Desiccant life improvement
- 5.8×
- mbar·L/s verified leak rate
- 1×10⁻⁹
- KOH recovered to process
- 98%
The challenge
The plant needed ISO 14687 Grade D hydrogen for a mobility offtake contract. Potassium hydroxide aerosol from the alkaline electrolyte was passing the standard separator and reaching the drying stage, where it degraded the desiccant and forced a change-out cycle six times shorter than design.
How we approached it
- 01Aerosol loading was measured directly at the separator outlet across the electrolyser's full load range, including ramping.
- 02Metallurgy was reviewed against hydrogen embrittlement criteria, moving the design to 316L with hardness control throughout.
- 03A coalescing stage was designed specifically for KOH aerosol, with drainage returning electrolyte to the process rather than to waste.
- 04Helium leak testing to 1×10⁻⁹ mbar·L/s was written into the acceptance criteria before fabrication began.
What we delivered
A SEPRA-H2 two-stage coalescer in 316L with hardness-controlled welds, PTFE coalescing media selected for alkaline compatibility, and electrolyte recovery back to the KOH loop. Helium leak tested and delivered with a full purity verification report.
Hydrogen exposes every assumption you carry over from natural gas. They arrived already knowing that, which saved us a learning cycle we could not afford.
Project facts
- Client
- Renewable hydrogen developer
- Industry
- Hydrogen & Fuel Cells
- Location
- Andalusia, Spain
- Year
- 2026
Measured results
- Grade D
- ISO 14687 purity achieved
- 5.8×
- Desiccant life improvement
- 1×10⁻⁹
- mbar·L/s verified leak rate
- 98%
- KOH recovered to process
What went in
Other programmes
Next step
Tell us what is in the stream.
Flow rate, contaminant, target rating, chemistry and available pressure. Six inputs, and our engineers return a staged design with the sizing basis attached — typically inside 48 hours.
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