Transcript Slide 1

Electrolysers for
Hydrogen Production
by Peter Sudol
Methods of Hydrogen Production
Hydrogen
Electrolysis of Water
Reforming of
Biogenic and
Fossil Fuels
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.
Hydrogen pipeline project in Totara Valley
Pipeline 2km
Wind
Energy
Fuel Cell
Electrolyser
Hydrogen Burner
Types of Water Electrolysis
Water Electrolysis
Alkaline Electrolysis
PEM Electrolysis
Steam Electrolysis
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
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
PEM Electrolyser (two cells)
Principle of a PEM electrolysis cell
Nafion - Membrane
hydrophilic
(polar)
hydrophobic
(nonpolar)
sulfonated polytetrafluorethylene
Cell Voltage [V]
UI characteristic curves of an electrolyser
Current density [mA/cm2]
Cell Voltage [V]
UI characteristic curves of an electrolyser
Current density [mA/cm2]
Cell Voltage [V]
UI characteristic curves of two electrolysers
Current density [mA/cm2]
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