19-11-04

New Zealand scientists have found a breakthrough method of purifying hydrogen, using iron sands, which may help the world to develop a clean-burning replacement for oil.

The process uses the North Island west coast's unique volcanic iron sands to help to extract pure hydrogen from water. The hydrogen could eventually replace oil in both cars and electricity generation, eliminating carbon dioxide emissions that are blamed for global warming.

The process of splitting water to extract the hydrogen needs a lot of energy, but the scientists at state-owned Industrial Research Ltd (IRL) believe the energy could be supplied by sawdust and other biomass wastes from the forestry industry. IRL hydrogen project manager Ian Brown said the company had applied for patents for the technology and believed it was unique.

"People have had ideas about using iron oxides, but as far as we can tell they have never figured out how to make it happen," he said. "No one has got it to demonstration plant stage. No one has contemplated using iron sands. No one has contemplated combining it with biomass technologies. It's the whole package of ideas that is unique."

Dr Brown previously led IRL's ceramic materials programme, which helped Auckland-based Pyrotek to create a world market for advanced ceramics used in the aluminium industry. He formed a hydrogen research team this year because another IRL unit developing fuel cells to store hydrogen needed a source of pure gas.

"All the existing fuel cell technologies internationally demand high-purity hydrogen because they have components that respond badly to contaminant gases," he said. "That is one of the difficulties of developing a fuel cell economy."

He said New Zealand had millions of tons of iron sand and had already developed an infrastructure to extract it for the steel mill at Glenbrook and for exports to Japan. There would be no need to extract large amounts, as the iron sand could be reused many times over.
"We are chemically changing it and then changing it back to what it was." His team is collaborating with two US Government-funded research groups -- on hydrogen generation at the National Renewable Energy Laboratory and on hydrogen storage at Los Alamos National Laboratory.

Dr Brown hopes to develop a 5 MW demonstration plant within five years, but expects that it may take 10 years to make the technology available commercially. He sees opportunities for New Zealand engineering companies to manufacture the processing plants and sell them around the world.
"There are also a lot of opportunities for applications and infrastructure and to devise technologies that make use of pure hydrogen, such as investigating fuel cell technologies for particular applications. It's going to change the way we live. Hydrogen technologies will have the same sort of impact as the computer and telephone."

Professor Ralph Sims, of Massey University's Centre for Energy Research, who is collaborating with the team, told the Royal Society's annual conference in Christchurch that biomass-based hydrogen could make New Zealand the first nation to be "fossil fuel and nuclear free". He said the biomass from forest wastes or other sources would provide energy and gas for a process that involved heating water into steam, then injecting it into other materials.
IRL is also working on a process to store the hydrogen inside solid materials which can hold large quantities of the gas more safely than in bottles.

Source: Fairfax New Zealand