If the Australian Parliament passes legislation that was introduced by the minister of resources and energy in mid-June, the country could have the world’s first legislative framework for storing carbon dioxide (CO2) offshore, in subsea geological formations. Australia, the fourth-largest producer of coal in the world, is currently under considerable pressure to find ways to sustain coal-fired power generation—which provides 83% of the country’s electricity—while responding to climate change concerns. One way to do this is to implement policies that aid the development of carbon capture and storage (CCS) technologies, Resources Minister Martin Ferguson said.
“As the world’s largest coal exporting nation it is in our economic interest to accelerate the development of technologies which extend the viability of coal fired electricity generation,” he said. As well as helping to avoid emissions,CCS would also be crucial to the sustainability of potential new industries such as coal-to-liquids, which could significantly improve Australia’s liquid transport fuel security, he said.
Ferguson said that Geoscience Australia, a national research agency, had already identified several potential storage sites in Victoria, Western Australia, and southern and central Queensland—areas that all have high carbon emissions. The identified formations in offshore waters “have the potential to securely store hundreds of millions of tonnes of carbon dioxide for many thousands of years,” he said. Ferguson added that geological formations that have stored oil and gas—and in some cases CO2—for millions of years are the same as, or similar to, the formations proposed for greenhouse gas storage.
The legislation has already been referred to the House of Representatives Primary Industries and Resources Committee for inquiry and report. If all goes as Ferguson expects,the government could invite proposals for CCS in the continent’s seabed as early as December—a key step that would encourage investment in and commercialization of seabed sequestration technology. Australia already leads efforts in the
An artist’s rendition of StatoilHydro’s Sleipner project, a large-scale subsea CO2 sequestration experiment in the Norwegian sector of the North Sea. Carbon dioxide is separated from the natural gas production stream (indicated in green) and reinjected into a saline reservoir 2,600 feet below sea level (shown here as blue). Courtesy: Alligator film /BUG / StatoilHydro
Southern Hemisphere to store CO2 on land. In July, the CO2CRC Otway Project announced it had successfully stored 10,000 tons of the gas 1.2 miles underground at a depleted natural gas reservoir in southwestern Victoria. The project’s chief executive confirmed that geosequestration subsurface monitoring showed the CO2 was behaving just as researchers had predicted. The group will now attempt to store another 10,000 tons underground, he said. To put the storage capacity of these “pilot projects” in perspective: A typical modern 600-MW pulverized coal plant running at 80% capacity factor will produce just under four million tons of CO2 a year—enough to top off the pilot reservoir in less than a day.
As well as conducting its own research,the country has been monitoring several seabed storage projects that are operational or are being planned around the world.Such international efforts were given a boost by a recent amendment to a 1996 Protocol to the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, which now exempts CO2 streams. As of February 2007, carbon storage under the seabed has been allowed,and contracting parties to the protocol have been working out new international guidelines on how to safely store CO2 in sub-seabed geological formations in a manner that meets the protocol’s requirements.
One of the world’s most celebrated CO2 projects is StatoilHydro’s Sleipner field,a large-scale experiment offshore in Norway, where more than 1 million tonnes of CO2 have been injected into a saline aquifer located 2,600 feet below the seabed since 1996. StatoilHydro removes natural gas and condensate from the Heimdal sandstone formation some 8,200 feet below sea level. Using an amine process, it separates the CO2 from the natural gas in a floating 65-foot-tall, 8,000-ton treatment plant and then injects it into the 650-foot-thick Utsira sandstone formation (above the Heimdal formation, to avoid contamination of the gas field), which is capable of holding 600 billion tonnes of CO2 by some estimates. The Sleipner project also includes a research and monitoring program to examine long-term storage, migration, and leakage.
But even with Statoil’s success at Sleipner field (the Norwegian government introduced a $60 per metric ton carbon tax in 1991 to spur interest in CO2 injection), Norway has yet to implement a clear regulatory framework concerning carbon capture—beyond the carbon tax. And unlike Australia, other countries prefer to generate commercial interest in CCS—although not necessarily subsea sequestration—before taking that step.
In July, for example, the UK shortlisted four of nine contenders that had entered a CCS demonstration competition to win $2 billion in government funding. Among the snubbed was a $60 billion scheme to capture two-thirds of carbon emissions from 18 Yorkshire power stations and industrial sites and store them under the North Sea. The project—a collaboration between several companies, including Yorkshire Forward, Corus, Scottish and Southern Energy, Powerfuel Power Ltd., BP, ConocoPhillips, E.ON UK, Shell, and Drax Power—could still rally private investment to become a reality, project members hope.