H2-DRY and H2-PURE: drying and purification solutions
Hydrogen purification is essential for achieving the required gas quality, protecting equipment, and ensuring reliable performance of downstream processes.
Production of hydrogen is possible through electrolysis or other methods (e.g. steam reforming, biomass gasification). But the process generates hydrogen-rich gas that contains moisture and residual oxygen.
Purification of hydrogen is crucial to ensure its safety, efficiency, and suitability for various industrial and energy applications especially for fuel cells.
At OMEGA AIR, we’ve developed H2-DRY and H2-PURE – fully automated systems engineered for continuous hydrogen drying and purification. Designed to deliver consistent performance, they efficiently remove oxygen while ensuring a reliable supply of high-purity compressed hydrogen gas.
Baptiste Calvet, Area Sales Manager at OMEGA AIR, explains:
“Year by year we developed the design of the dryer, added new features (DeOxo, instrumentation, etc.), proposed packages (SKID, container), and most importantly improved the technology so that today we manufacture more than 50 units per year, with the highest efficiency possible (0% H2 loss) and purity levels of 1 ppm O2 and H2O if needed.”
Evolution of H2-DRY: through design, technology, assembly
The development of hydrogen technologies requires not only hydrogen production, but above all ensuring proper purity and process stability.
We developed a hydrogen dryer and purifier that can clean the hydrogen to over 99.999% purity, which makes it suitable for sensitive applications like fuel cells according to ISO 14687:2019.
At OMEGA AIR we have engineered and manufactured three hydrogen drying solutions:
H2-DRY systems ensure continuous removal of water vapour from compressed hydrogen, precisely controlling pressure dew point and protecting downstream processes.
H2-PURE units deliver advanced purification by eliminating water vapour, oxygen, and solid particles—meeting the stringent requirements of all hydrogen applications, including fuel cells in accordance with ISO 14687:2019.
H2 BOX represents a fully integrated hydrogen station, combining purification technology within a compact, containerized solution. Designed for outdoor use, it is weather-resistant, highly mobile, and enables rapid deployment of hydrogen infrastructure.
The system is engineered for maximum efficiency and process stability. It operates with zero hydrogen loss, while maintaining consistent performance regardless of inlet load variations (0–100%). Fully automated operation ensures continuous, reliable performance without operator intervention, even under dynamic process conditions.
How H2-DRY and H2-PURE work
The drying operation of the dryers is based on adsorption, where molecules adhere to the surface of a highly porous adsorbent (desiccant) through electrostatic and molecular forces.
Drying of the gas takes place under pressure inside two pressure columns filled with adsorbent material (activated alumina) which are operated alternately over three main phases of the process (adsorption, heating, cooling) followed by column switchover after saturation of the adsorbent.
The hydrogen purification process uses a DEOXO reaction to remove oxygen from the gas stream. This reaction catalyzes the combination of hydrogen and oxygen to form water, which is then condensed on the heat exchanger. DeOxo unit reduces oxygen content down to <5 ppm, even 1 ppm if needed.
Adsorption/Drying
In this phase, gas under pressure is being dried while flowing through one of the pressure vessels. While one column is in the adsorption phase other column is undergoing regeneration. Drying on one column is up to 6 working hours at nominal conditions.
Regeneration
During the regeneration phase, all the water which was captured by the adsorbent during the adsorption phase is being removed from the device. When the regeneration phase is completed, adsorbent is fully regenerated and ready for next adsorption phase. Regeneration starts with heating. The column that is in regeneration is placed in a closed loop recirculation water removal system, from top-to bottom of the column. Duration of the regeneration is up to 4 hours.
With advanced hydrogen purification and drying systems, OMEGA AIR actively contributes to the development of hydrogen supply infrastructure and supports projects that enable decarbonization in industry, mobility, and energy sectors. Through expertise, experience, and a comprehensive approach, we help partners transform hydrogen potential into concrete, implementable solutions.
Technical Specifications of H2 DRY dryers
OMEGA AIR hydrogen dryers and purifiers use temperature swing adsorption (TSA) technology.
TSA technology is a hydrogen purification method that is using temperature-dependent adsorption characteristics of gas molecules on solid adsorbents. During the drying phase, a gas mixture containing hydrogen is passed through a fixed bed of adsorbent material, typically activated alumina, silica gel, or molecular sieves, at a low temperature.
Compressed hydrogen dryers are usually custom-made in order to meet specific project requirements. Provided that the oxygen level (or any other reactive component) in the gas mixture is reduced to a minimum, several versions are available depending on operating pressure, temperature, and required pressure dew point.
Regeneration is heat-based. Depending on the availability and type of fluids used for regeneration and cooling, dryer components are adapted to ensure minimal gas loss (maximum 1–2% when external dry gas is available for regeneration/cooling).
Operating pressure
Up to 37 (45) bar
Inlet temperature
Up to +80 °C
Ambient temperature
1.5 °C to 50 °C (check also blower suction conditions)
Pressure dew point
-40 °C (lower PDP on request)
Voltage, Frequency
400 V, 50 Hz
Protection class (controller)
IP 65
Communication
Modbus TCP/IP, Profinet TCP/IP (other on request)
Certification
CE/ATEX (IECEx on request)
HP-DRY dryer is suitable for easy integration in electrolyser hydrogen package. Version “HP” consumes up to 2% of hydrogen for regeneration while version “X” performs regeneration in closed loop meaning zero hydrogen is wasted during regeneration.
Conclusion
Over the years, OMEGA AIR has continuously refined its hydrogen dryers.
The journey of H2 drying and purifying units mirrors the journey of the whole company – from bold beginnings to high-end products, thanks to continuous investment in R&D and production.
Partnering with OMEGA AIR goes beyond equipment — it’s a collaboration on advanced, sustainable hydrogen solutions. With proven expertise, innovative technology, and a project-driven approach, we ensure safe, efficient hydrogen use while supporting faster deployment of next-generation, low-carbon infrastructure.
Inquiry
OMEGA AIR d.o.o. Ljubljana
Cesta Dolomitskega odreda 10
1000 Ljubljana
Slovenia
Cesta Dolomitskega odreda 10
1000 Ljubljana
Slovenia
- +386 (0)1 200 68 00
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