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Development of separators for alkaline water electrolysis cell

 Fig. 1: Alkaline electrolysis cell

In recent decades, renewable energy sources like wind power and photovoltaics have become a mature wide-spread technology. Increase of their share is limited by their intermittent operation and by the lack of suitable energy storage technology. Alkaline water electrolysis is expected to become a part of large–scale Power-to-gas (PtG) conversion systems, where excessive renewable power is converted into synthetic fuel – hydrogen.

Inter-electrode separator is a key component of the electrolysis cell affecting its efficiency and purity of the produced hydrogen and oxygen. Traditional asbestos separators may no longer be used and new composite separators are still expensive. Some of the

 Fig. 1: Alkaline electrolysis cell

common polymer materials possess suitable mechanical properties and chemical stability but lack the required wettablility. Our objective is to modify these materials by interaction with low-temperature plasmas and generate the required surface properties.

  

 

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Fig. 2: Electrolysis cell layout

 

 Obr. 3

Fig. 3: Electrolysis cell for separator resistance measurements

(4-contact configuration with reference electrodes)

 

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 Fig. 4: Electrolysis system for gas purity measurements

 

Plasma sources

  • Diffuse coplanar Surface Barrier Discharge (DCSBD)
  • Low-pressure RF discharge

Diagnostics of plasma modified membranes: 

  • Surface wettability (WCA, CWST)
  • Surface chemical composition (ATR-FTIR)
  • Ageing tests in aqueous KOH at controlled temperature
  • Electrolysis cell for determination of electrical resistance using Hg/HgO reference electrodes
  • Electrolysis cell for gas permeability and H2/O2 cross-contamination measurement

 

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Fig. 5: Cell voltage (left) and purity of produced gases (right) as a function of cell current density using different separators

 

Optimization of hydrogen flame burners for low emissions of nitorogen oxides

 

Although hydrogen is a very clean fuel, its combustion at elevated temperature initiates reactions of atmospheric nitrogen and oxygen resulting in formation of nitrogen oxides. Both NO and NO2 are harmful to human health and their formation in all combustion processes should be minimized. This is especially important for indoor gas apliances like stoves.

 

The main aim of research 

  • Study of formation of nitrogen oxides in diffusion and premixed hydrogen flames in air
  • Study of stability of premixed hydrogen flames in respect to flashback and flame lift
  • Design of variable power burners with high turn-down ratio and low emissions of NOX

 

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Contacts:

RNDr. Michal Stano, PhD.
F2 – 84
Email: stano(at)fmph.uniba.sk
Phone Nr.: +421 2 602 95 240

Mgr. Ľubomír Staňo
F2 – 74
Email: lubomir.stano(at)fmph.uniba.sk
Phone Nr.:  +421 2 602 95 581