SO2 - an indirect source of energy

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Date
2013Author
Kriek, R.J.
Van Ravenswaay, J.P.
Potgieter, M.
Calitz, A.
Lates, V.
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Show full item recordAbstract
Global sulphur dioxide (SO ) emissions peaked around the mid-
1970s, after which they declined. However, with the growth of specifically
China, emissions are on the rise again. In 2008, global anthropogenic
SO emissions totalled 127 Mt, with energy production
accounting for 63.2 Mt and metal-related processes 12.8 Mt.
As a well-known gaseous pollutant, SO is not per se known as a
source of energy. However, in the presence of water SO can be
electro-oxidized at the anode of an electrolyser to produce hydrogen
ions, which in turn can be reduced at the cathode of the electrolyser
to produce hydrogen gas. Gaseous emissions of SO can therefore be
cleaned up with the simultaneous production of hydrogen, an energy
store or carrier, which provides an economic offset to the overall cost
of this potential remediation process. This process forms part of the
Hybrid Sulfur (HyS) cycle as well as the once-through HyS (OTHyS)
cycle.
Indications are that the greatest stride towards the development
of an effective electrolyser for the electro-catalytic oxidation of SO
requires the development of an anode electrocatalyst exhibiting
enhanced activity for the electro-oxidation of SO . A critical review
will be presented on the research and development of such an anode
electrocatalyst, and a strategy for a more effective research and
development effort will be discussed. This will include theoretical
studies on the electro-catalytic oxidation of SO on different metalbased
catalytic surfaces (for which some preliminary results are
presented) in conjunction with combinatorial (simultaneous multimetal
multi-electrode) electrochemistry studies as well as singleelectrode
electrochemistry studies.