Nuclear Production of Hydrogen, Fourth Information Exchange ...

SOUTH AFRICA’S NUCLEAR HYDROGEN PRODUCTION DEVELOPMENT PROGRAMME
The hydrogen production technologies that will be evaluated are represented in Figure 1 and cover
a wide range of technologies. This paper will focus on the large scale hydrogen production technologies
and especially the ones coupled to a nuclear heat source, namely thermochemical water-splitting via
the hybrid sulphur (HyS) process and hydrogen production using the plasma-arc process.
Figure 1: Energy source, H 2 production technology and H 2 infrastructure CC identified projects
Energy Source
Renewable
H 2 Production
Technology
H 2 Projects
Solar
Photolytic
Water Splitting
Small Scale
Distributed H 2
production
Large Scale
Centralized H 2
Production
Wind
Photo-Biological
Processes
Bacterial bio-H 2
Algal H 2
Hydro/Wave
Electricity
Electro-chemical
Water Splitting
H 2 O – electrolyzer
H 2 from renewables
HTSE (Solar)
Biomass
Hi-Temp
Heat
Thermo-chemical
Water Splitting
Techno-Econ.Studies
HyS
SO 2 – electrolyzer
Solar FeO/Fe 2 O 3
Nuclear
LWR
Gasification
Biomass Gasification
Solar coal gasification
HTGR
Steam Methane
Reforming
Plasma Arc Reactor
Solar SMR
Coal
Fossil
Natural Gas
NWU lead
CSIR lead
Thermochemical water-splitting programme
Thermochemical water-splitting is seen as a promising technology to produce hydrogen on a large
scale. High temperature gas-cooled reactors (HTGR) produce heat at the temperatures needed for high
yield hydrogen production. The Hydrogen Infrastructure CC identified thermochemical water-splitting
as a key programme to make a significant contribution to technology development, which will build
on the RSA strengths in high temperature reactors and its acumen in the Fischer-Tropsch technology,
and with a good potential to lead to exportable technology in the form of products and systems.
Figure 2 indicates how the application of process heat from HTGR (and/or concentrated solar),
integrated with a water-splitting technology, can be used to produce hydrogen and oxygen which
serves as feedstock for a coal-to-liquids (CTL) process. A clean source of hydrogen will enable CTL
producers to significantly reduce CO 2 emissions in producing liquid fuels, and will hence impact the
existing transport sector emissions through cleaner liquid fuels. However, once the necessary hydrogen
transport infrastructure is established, the carbon-free hydrogen could be provided as merchant
product for hydrogen-powered vehicles as well as for other industries such as steel manufacturers
and other chemical industries such as steel production and ammonia production for fertilisers.
Hybrid sulphur hydrogen production project
The hybrid sulphur process (HyS) as shown schematically in Figure 3 is a partially thermochemical
and partially electrolytic water-splitting process using approximately 80% of the energy as heat and
20% of the energy as electricity to generate hydrogen and oxygen in a two-step process as shown
in Figure 3. The HyS process was developed by Westinghouse in the early 1970s (Brecher, 1977).
206 NUCLEAR PRODUCTION OF HYDROGEN – © OECD/NEA 2010