The
main obstacle in the commercial exploitation of water electrolysis for
large scale hydrogen production is the high electricity consumption which
makes the process economically unattractive.
Prof. Shen, from Advanced Energy
Materials Research laboratory of Sun Yat-Sen University, has developed
an innovative approach, as well as an economic way, to produce hydrogen
by alcohol electrolysis. In this way, only 1/3 electricity consumption
will be required compared to water electrolysis.
The principle of the electrolysis
of methanol is explained as follows. Methanol is oxidized via a dehydrogenation
process at the anode and the resulting H+ ions then diffuse through the
proton exchange membrane (PEM) to the cathode chamber where they are reduced
to hydrogen gas.
A promising advantage is that the
standard potential is only 0.02 V vs. NHE for methanol oxidation compared
to 1.23 V for water electrolysis. Moreover, the hydrogen generated originates
not only from the alcohol but also from the water during the electrolysis
processes according to the overall equation (3):
At anode: CH3OH + H2O = 6H+
+ CO2 + 6e- Eo = 0.02 V vs. NHE
(1)
At cathode: 2H+ + 2e- = H2
(2)
Overall: CH3OH + H2O
= 3H2 + CO2
(3)
The combination of this electrolyser
concept with solar cells would economically produce hydrogen for storage
and subsequent use in, or for on-spot use in fuel cells and chemical engineering
applications.
The two techniques are assembled
to one set as shown below. Such sets are ideal for education, demonstration,
research and other applications. These originally invented sets are ready
to mass production.
Features:
Easy to operate
Compact
Reliable
Technical specifications
Electrolyser(alcohol): 0.2 - 1.0 V,
0.0 to 2 A
Electrolyser(water): 1.5
- 2.5 V, 0.0 to 1 A
Electrode surface:
16.0 cm2

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