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REHOVOT, Israel, August 10, 2005 (Refocus
Weekly)
The Weizmann Institute of Science is using its
concentrating solar facility to produce hydrogen fuel from direct
sunlight.
The project involves collaboration with the Swiss Federal
Institute of Technology, the Paul Scherrer Institute in Switzerland,
Institut de Science et de Genie des Materiaux et Procedes - Centre
National de la Recherche Scientifique in France, and ScanArc Plasma
Technologies in Sweden. The project is supported by the European
Union's FP5 program.
The technology uses the 64 concentrating mirrors at Weizmann’s
facility in Rehovot to heat zinc oxide to 1,200 degrees Celcius in
the presence of wood charcoal. The process splits the ore, releasing
oxygen and creating gaseous zinc, which then is condensed to a
powder.
The zinc powder will react with water to yield hydrogen for use as a
fuel, and the zinc oxide is recycled back to zinc in the solar
plant. In recent experiments, the 300 kW installation produced 45 kg
of zinc powder from zinc oxide in one hour, the centre explains.
Hydrogen is expected to become a pollution-free fuel of the future,
but nearly all current hydrogen is produced by expensive processes
that require combustion of fossil fuels, and there are storage and
transportation constraints. This new process creates a storable
intermediate energy source from metal ore and the “innovative solar
technology may offer a green solution to the production of hydrogen
fuel,” says scientists who released the test results at the Solar
World Congress of the International Solar Energy Society in Florida.
The process generates no pollution, and the zinc can be stored
easily and transported for conversion into hydrogen on demand. The
zinc can also be used directly in zinc-air batteries, which convert
chemical to electrical energy.
“After many years of basic research, we are pleased to see the
scientific principles developed at the Institute validated by
technological development,” says professor Jacob Karni at Weizmann.
“The success of our recent experiments brings the approach closer to
industrial use,” adds project leader Michael Epstein.
The splitting of metal ores with solar energy has been under
development for several years at the Weizmann Institute's Canadian
Institute for the Energies & Applied Research. The research facility
has a solar tower and a field of 64 mirrors that are 7 by 8 m in
size and driven by sun-tracking motors.
Scientists are investigating ores other than zinc oxide, as well as
additional materials that may convert sunlight into storable energy.
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