Solar hydrogen – the fuel of the future
4th March 2003
 |
Another of Jules Verne’s visionary scientific predictions is edging towards fulfilment in a UNSW laboratory.
Writing in The Mysterious Island in 1874 Verne said: “Water will be the coal of the future”. He was seeing ahead to the time when humankind had exhausted its one-off supply of fossil fuels and would be forced to turn to a truly sustainable – and therefore everlasting – source of energy.
We have heard much hype about the hydrogen economy – pollution-free transport and clean skies, all from burning clean hydrogen, where the only combustion product is steam. But where does this hydrogen come from?
Most comes from natural gas, through a process called steam reforming in which methane and steam are heated together to produce hydrogen and carbon dioxide. This is the dominant technology, because it produces the cheapest hydrogen, but it fails to address two problems: natural gas is a finite resource which is going to run out, and the unwanted carbon dioxide is the major cause of global warming.
As Verne noted, an elegant solution is to produce hydrogen from non-fossil fuel energy sources. This includes the energy needed to drag the hydrogen away from the atoms it is attached to. And the only permanent energy source is the sun.
This is why Professors Chris Sorrell and Janusz Nowotny, Dr Tad Bak and six PhD students in UNSW's centre for materials research in energy conversion are striving to find the most efficient way of using solar energy to split water, the only abundant and suitable source material, into hydrogen and oxygen. The UNSW team is the only one in Australia working on the direct solar splitting of water into its two gases.
After surveying many photoelectric compounds – compounds that exhibit electrical behaviour when light shines on them – the UNSW team has settled for titania, or titanium dioxide, because it has the right electrical properties and the highest resistance to water corrosion. The fact that Australia has extensive titania (rutile) deposits is no disincentive.
“Titania is a jack-of-all-trades,” said Sorrell. “It can do an extraordinary range of things – from killing bacteria to splitting water – but it is not always as efficient as we would like. Commercial, unmodified titania, which is usually thought of as TiO2, or two oxygen atoms for every titanium atom, has a relatively low efficiency in using the sun’s energy to split water.
“We have found how the efficiency of commercial titania can be increased by a factor of 10 to 50. These results, which we have recently patented, have attracted considerable industrial interest and indicate we could have the nucleus of an entirely new energy technology.
“If we can raise the efficiency of this reaction above 10 per cent, our process will be commercially viable, according to the US Environmental Protection Agency. Of course there is much more to a mature industry than that but we, and perhaps thousands of others around the world, are working on it,” he said.
When the Vice-Chancellor, Professor Rory Hume, visited the group’s laboratory he said Australia should strive to move to a renewable hydrogen economy and added: “This should be a priority area for Australian R&D. I hope that both the government and Australian industry will consider the long-term effects of moving to a clean hydrogen technology and continue to invest in promoting this transition.”
So what of the future? The European Commission’s sixth framework program claims hydrogen as a transport fuel will be a mature technology by 2020 and has instituted an intense R&D program in pursuit of this goal. Across the Atlantic, the US Government has just committed an extra $US1.2 billion to hydrogen research.
The Australian Government hopes to have formulated a national hydrogen strategy by August. But if Australia is to be a player in the inevitable global shift to a hydrogen economy, our government will have to address the wisdom of Jules Verne’s prophecy.
With our substantial rutile deposits, abundant sunshine, wide-open spaces and proximity to some of the world’s fastest-growing energy markets, Australia has the opportunity to become a major clean energy exporter.
Writing in The Mysterious Island in 1874 Verne said: “Water will be the coal of the future”. He was seeing ahead to the time when humankind had exhausted its one-off supply of fossil fuels and would be forced to turn to a truly sustainable – and therefore everlasting – source of energy.
We have heard much hype about the hydrogen economy – pollution-free transport and clean skies, all from burning clean hydrogen, where the only combustion product is steam. But where does this hydrogen come from?
Most comes from natural gas, through a process called steam reforming in which methane and steam are heated together to produce hydrogen and carbon dioxide. This is the dominant technology, because it produces the cheapest hydrogen, but it fails to address two problems: natural gas is a finite resource which is going to run out, and the unwanted carbon dioxide is the major cause of global warming.
As Verne noted, an elegant solution is to produce hydrogen from non-fossil fuel energy sources. This includes the energy needed to drag the hydrogen away from the atoms it is attached to. And the only permanent energy source is the sun.
This is why Professors Chris Sorrell and Janusz Nowotny, Dr Tad Bak and six PhD students in UNSW's centre for materials research in energy conversion are striving to find the most efficient way of using solar energy to split water, the only abundant and suitable source material, into hydrogen and oxygen. The UNSW team is the only one in Australia working on the direct solar splitting of water into its two gases.
After surveying many photoelectric compounds – compounds that exhibit electrical behaviour when light shines on them – the UNSW team has settled for titania, or titanium dioxide, because it has the right electrical properties and the highest resistance to water corrosion. The fact that Australia has extensive titania (rutile) deposits is no disincentive.
“Titania is a jack-of-all-trades,” said Sorrell. “It can do an extraordinary range of things – from killing bacteria to splitting water – but it is not always as efficient as we would like. Commercial, unmodified titania, which is usually thought of as TiO2, or two oxygen atoms for every titanium atom, has a relatively low efficiency in using the sun’s energy to split water.
“We have found how the efficiency of commercial titania can be increased by a factor of 10 to 50. These results, which we have recently patented, have attracted considerable industrial interest and indicate we could have the nucleus of an entirely new energy technology.
“If we can raise the efficiency of this reaction above 10 per cent, our process will be commercially viable, according to the US Environmental Protection Agency. Of course there is much more to a mature industry than that but we, and perhaps thousands of others around the world, are working on it,” he said.
When the Vice-Chancellor, Professor Rory Hume, visited the group’s laboratory he said Australia should strive to move to a renewable hydrogen economy and added: “This should be a priority area for Australian R&D. I hope that both the government and Australian industry will consider the long-term effects of moving to a clean hydrogen technology and continue to invest in promoting this transition.”
So what of the future? The European Commission’s sixth framework program claims hydrogen as a transport fuel will be a mature technology by 2020 and has instituted an intense R&D program in pursuit of this goal. Across the Atlantic, the US Government has just committed an extra $US1.2 billion to hydrogen research.
The Australian Government hopes to have formulated a national hydrogen strategy by August. But if Australia is to be a player in the inevitable global shift to a hydrogen economy, our government will have to address the wisdom of Jules Verne’s prophecy.
With our substantial rutile deposits, abundant sunshine, wide-open spaces and proximity to some of the world’s fastest-growing energy markets, Australia has the opportunity to become a major clean energy exporter.
Share on Facebook Add to Del.icio.us Digg this story |