Efficient filtration for green hydrogen

Perfect for ultrapure water production: WS Sanitary Housing: The high-gloss polished WS Sanitary housings made of stainless steel are used at the end of the process in ultrapure water production with WFPES-E membrane filter candles as a "police filter" to ensure quality. (Photo: Martin Wolf Wagner)

Self-standing WTKF stainless steel housings: In combination with depth filter candles, the housings are ideal as pre-filters, particle filters, and fine filters before water treatment systems. An inwardly curved housing bottom facilitates residual drainage. (Photo: Martin Wolf Wagner)

WFPPA and WFMLP pleated elements: With a long service life and an absolute separation efficiency of 99.9% at low differential pressure, the pleated elements meet all requirements for pre- or final filtration in pure water production. (Photo: Martin Wolf Wagner)

Hydrophilic WFPES-E Membrane Filter Cartridges: WFPES-E membrane filter cartridges are already pre-filtered with ultrapure water and individually integrity tested. In filtration fineness from 0.2 μm to 0.04 μm, they are used as final filters for sterilization in ultrapure water production before the ultrapure water is split into hydrogen (H2) and oxygen (O2) in electrolysis. (Photo: Martin Wolf Wagner)

CP- / CP2 Deep Filter Cartridges as Protective Filters: When producing pure water, an ion exchanger is usually used. In the feed line, there is a particulate filter of type CP or CP2. (Photo: Martin Wolf Wagner)

Green hydrogen is considered a key technology for the energy transition. For efficient electrolysis, pure water is essential. Wolftechnik offers customized filtration solutions that ensure reliable water treatment and maximize the efficiency of electrolyzers.

The production of green hydrogen occurs through electrolysis, where water is split into oxygen and hydrogen using electricity from renewable energy sources. To ensure this process runs smoothly and with maximum efficiency, the water used must have an exceptionally high purity. Even the smallest impurities can burden the electrolysis cells, cause deposits, and significantly shorten the lifespan of the system. Wolftechnik's filtration systems make a crucial contribution here by removing particles, microorganisms, and dissolved substances, thereby ensuring consistently high water quality.

Filtration as the key to pure water production

Filtration begins right at the first step of water treatment, where coarse suspended solids and particles are removed. Wolftechnik's WFPPA and WFMLP pleated elements are used here, which, with their high dirt-holding capacity, enable efficient pre-filtration and protect the downstream reverse osmosis system from contamination. In the system, water is pressed through a semi-permeable membrane, removing up to 99 percent of dissolved ions, organic compounds, and microorganisms. This step significantly reduces the salt content of the water and produces so-called pure water.

To achieve even higher purity, the water then undergoes deionization. Here, dissolved anions and cations are removed to minimize conductivity. In this process step, the use of depth filter candles of the types CP and CP2 is particularly important, as they filter out particles from the water and thus protect the sensitive ion exchangers from contamination. The result is nearly completely pure water with a maximum conductivity of 0.055 μS/cm – an essential value for electrolysis.

In the final step, the pure water undergoes a sterilizing filtration. WFPES-E membrane filter candles ensure that even the finest microorganisms and particles are removed, so the water reaches the required quality for hydrogen production. This final filtration is critical for the long-term operational safety of the electrolyzer, as it prevents deposits and thus guarantees the efficiency of the entire process.

Since pure water is particularly aggressive due to the absence of dissolved ions, only highly durable materials are used throughout the treatment system. Wolftechnik offers stainless steel housings such as the high-gloss polished WS sanitary housings or the self-standing WTKF stainless steel housings, which meet the highest hygienic and mechanical requirements. The housings ensure safe and durable filtration for all process steps.

Summary of filtration solutions

Pure water must be free of ions, particles, and microorganisms. To achieve this high purity, the water passes through multiple filtration stages:

– Pre-filtration: WFPPA and WFMLP pleated elements protect reverse osmosis systems from deposits and ensure efficient pre-filtration.
– Particle filtration: CP and CP2 depth filter candles eliminate fine contaminants before deionization in the ion exchanger.
– Final filtration & sterilization: WFPES-E membrane filter candles ensure absolute sterility and the highest water purity for electrolysis.