Electrolysers for Hydrogen Production

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Electrolysers for Hydrogen Production

• by
  Peter Sudol

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Methods of Hydrogen Production
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Uses of the Water Electrolysis

• Submarines, space stations (generation of
  breathing oxygen)
• Medical, chemical and other special applications
• In great quantities, economic only in those
  regions of the world where electric power can be
  generated very cheaply. This is the case almost
  exclusively in big hydroelectric plants (e.g. in
  Egypt, Iceland, Norway..).
• In the increasing renewable energy market, Water
  Electrolysis can be used for compensation of the
  differences between the demand and supply of
  energy from the variable renewable energy
  resources.

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Hydrogen pipeline project in Totara Valley
Fuel Cell
Pipeline 2km
Wind Energy
Electrolyser
Hydrogen Burner
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Types of Water Electrolysis
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Characteristic PEM Electrolysis Alkal. Electrolysis
Max. pressure of electrochemically generated H2 can be designed to generate H2 at press. of 2000 psi or greater lower pressure of electrochemically generated H2
Efficiency lower parasitic energy losses best alkaline electrolys. have still better efficien. (high heating value)
Hydrogen/Oxygen Pressure up to 3,000 psi differential pressure demonstrated very small differential pressure tolerated
Purity of the hydrogen output higher lower
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Characteristic PEM Electrolysis Alkal. Electrolysis
Compatibility with renewable energy systems best suited for plants with varying output work better in larger systems which are connected to the power grid
Hazardous materials none, system uses clean water only, no hazardous waste system uses KOH, waste disposal rules may apply
Occupational safety no special safety equipment required may require eyewash station or full-body shower
Explosion risk H2 released safely via normally open valves at shutdown or power failure requires special controls to allow for a safe reaction between O2 and H2
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PEM Electrolyser (two cells)
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Principle of a PEM electrolysis cell
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Nafion - Membrane
hydrophilic (polar)
hydrophobic (nonpolar)
sulfonated polytetrafluorethylene
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UI characteristic curves of an electrolyser
Cell Voltage V
Current density mA/cm2
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UI characteristic curves of an electrolyser
Cell Voltage V
Current density mA/cm2
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UI characteristic curves of two electrolysers
Cell Voltage V
Current density mA/cm2
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Further Steps in the Research Project

• Simulating the distributed energy system in the
  laboratory
• Determination of the efficiency of the whole
  system
• Optimisation of the efficiency
• Observing the performance of the electrolyser at
  different temperatures, different pressures,
  different inputs
• Observing the distribution and pressure of
  Hydrogen in the pipeline
• Observing the performance of the fuel cell