* Adding aluminium speeds hydrogen production from rocks
* Scaled up, could herald wider use of clean-burning fuel
By Environment Correspondent Alister Doyle
OSLO, Dec 8 (Reuters) - Scientists have produced hydrogen byaccelerating a natural process found in rocks deep below theEarth's surface, a short-cut that may herald the wider use ofwhat is a clean fuel, a study showed on Sunday.
Used in rockets and in battery-like fuel cells, hydrogen isbeing widely researched as a non-polluting fuel, but its use isso far hampered by high costs. A few hydrogen vehicles arealready on the roads, such as the Honda FXC Clarity andMercedes-Benz F-Cell, and more are planned.
Researchers in France said aluminium oxide speeded up aprocess by which hydrogen is produced naturally when water meetsolivine, a common type of rock, under the high temperatures andpressures found at great depths.
"We have overcome a preliminary step for a carbon-freeenergy production," lead researcher Muriel Andreani of theUniversity Claude Bernard Lyon 1 in France told Reuters.
The addition of aluminium oxide accelerated the naturalprocess by between 7 and 50 times, using temperatures of between200 and 300 degrees Celsius (400-570 Fahrenheit) at a pressureequivalent to twice the depth of the deepest ocean.
In the process, olivine turns into the mineral serpentineand water splits into its components, hydrogen and oxygen.
Currently, the most widely used technology for producinghydrogen - separating it from natural gas - requires far highertemperatures of 700 degrees Celsius (1,300 Fahrenheit) andreleases heat-trapping carbon dioxide as a by-product.
Using lower temperatures would save energy and money.
Fuel cells, which meld hydrogen with oxygen in the air toyield electricity, emit only water. That makes them attractiveas a way to cut greenhouse gas emissions and air pollution.
Far more research is needed to see if the French findingscould be increased to a commercial scale, said Jesse Ausubel ofthe Rockefeller University in New York.
"Scaling this up to meet global energy needs in acarbon-free way would probably require 50 years," he said in astatement. "But a growing market for hydrogen in fuel cellscould help pull the process into the market."
The findings will be presented to the American GeophysicalUnion, meeting in San Francisco from Dec. 9-13, after an initialreport in the journal American Mineralogist in October.
The work is part of the Deep Carbon Observatory (DCO), a10-year project due for completion in 2019 involving 1,000researchers in 40 nations.
Among puzzling DCO findings, experts said, microbes livingin tiny fissures in deep rocks where hydrogen forms naturally,often continents apart, seem to be related to one another inwhat may be a "deep subterranean microbe network".
Matt Schrenk of Michigan State University said life extendedto at least 4 or 5 km (2.5-3 miles) deep under land, and it wasunclear how similar microbes had spread to places as far apartas South Africa, North America and Japan.
"It is easy to understand how birds or fish might be similaroceans apart, but it challenges the imagination to think ofnearly identical microbes 16,000 km apart from each other in thecracks of hard rock at extreme depths," he said.
The DCO project is trying to combine chemistry, biology,geology and even astrophysics. "It is a path to discoverybetween new areas of science," Robert Hazen, head of the DCO atthe Carnegie Institution of Washington, told Reuters.
- Nature & Environment