Finishing - July-August 2022

34 PLATING
Electrolysis as a component of
renewable, electricity-based
hydrogen production
Power-to-gas is the conversion of electrical
energy into gas and refers to the chemical
process for producing (fuel) gas from water.
The conversion process takes place through
water electrolysis and a partially downstream
methanation process. The resulting fuel gas is
then stored and can be used in a variety of
ways. Producing hydrogen by means of
electrolysis is thus a pivotal step in the
transformation between the electrical energy
system and the downstream sectors of
application. The use of power-to-gas
technology makes particular ecological sense if
electricity from renewable sources, such as
solar or wind power, can be used to produce
the gas.
How water electrolysis works
Hydrogen is a component of water and
nearly all organic compounds. It is the most
common chemical element and therefore very
abundant. Hydrogen has the chemical formula
H and is usually gaseous and lighter than air.
However, hydrogen only occurs in nature in
compound form, for example as a component
of water. In order to use it as a source of
energy, gaseous hydrogen must first be
extracted from water or methane, e.g. by
means of electrolysis. Electrolysis utilises
electricity supplied via electrodes to separate
water into its two components, oxygen and
hydrogen. In the process, two water molecules
are split into two hydrogen molecules and one
oxygen molecule. The resulting hydrogen is
then methanised through the addition of
carbon dioxide. It can then be fed into the
natural gas grid, for example ("further
processing" of the hydrogen).
Role of surface technology
Apart from research and development,
engineering services and plant construction,
surface technology is also playing a vital role
in making hydrogen-based technologies fit for
the future. By developing the corresponding
functional layers, surface technology can
provide the parts and components used in
hydrogen technology with new properties –
such as adding protective functions that make
them more durable, effective and efficient.
Plating options for hydrogen
technology
The Holzapfel Group can plate the
components used in electrode packages, such
as anodes, cathodes, separator plates and end
plates, but also cell frames and water-bearing
components, with a functional layer that
protects them from corrosion. Components up
to a size of 2300 x 2100 mm can be plated
for use in alkaline water electrolysis. Other
processes such as electroless nickel, nickel
sulphamate, electroplated nickel, silver, tin,
zinc-nickel and other coating combinations are
also available.
First and foremost, it is necessary to plate
the various components in order to ensure the
durability and service life of the entire system.
Applying a corrosion protection layer can
make the parts considerably more resilient and
a crucial reason is the improvement the
plating brings in terms of efficiency. From a
mechanical point of view, this treatment
ensures the electrode packages deliver optimal
performance. Compared to nickel plating, the
Holzapfel Group's processes ensure
significantly greater efficiency and thus a more
economical mode of operation due to their
lower energy consumption.
Moreover, the Holzapfel Group develops,
produces and assembles complete, customised
electrode packages with gas-tight, materially
bonded connections.
Automated Water & Effluent Ltd have been supplying process control equipment
to the metal finishing and surface finishing industry.
We have an in-house team of qualified engineers able to design and build
control panels and process equipment specific to fit your requirements.
A wide range of our control instrumentation, dosing pumps and chemical process
equipment is available on short delivery.
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TODAY ON
01785 254 597
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Finishing – July/August 2022
AWE House, Antom Court, Tollgate
Industrial Estate, Stafford, ST16 3AF
awe-ltd.co.uk 01785 254 597