Sustainable Affairs: CO2: New technology would store carbon underground

Standing near an 800-meter-deep bore hole in the ground here, Frank Schilling picked up a fist-sized cylinder of sandstone and poured water onto its surface, watching the tiny stream skitter until it suddenly disappeared inside the rock's porous body.

The rapid absorption of the water , he said, showed how easily a much-less benign substance - carbon dioxide - could be stored once he and a team of researchers started pumping it into the half-mile-deep shaft.

"Everyone assumes we're going to store carbon dioxide inside of a cavern but the key is the tiny holes in this rock," said Schilling, a professor of mineral and rock physics. "We're going to press in the carbon dioxide and push out the salty water that's already there."

Schilling is spearheading a project near this small town about 20 kilometers, or 12 miles, west of Berlin that could change the way countries and industries store carbon dioxide, a fast-growing type of pollution, for generations to come.

Even as the drive to reduce greenhouse gases linked to global warming picks up, a number of countries are increasingly turning to coal as a major source of energy. The push for wide-scale development of coal that is quickly gaining in China is also growing steadily in some parts of Europe and the United States, forcing governments and businesses to consider how to dispense with carbon dioxide, a harmful side-product.

Several countries already bury carbon dioxide in sites off shore. At an undersea saline aquifer off Norway, Statoil buries carbon dioxide extracted from natural gas to avoid paying pollution taxes to the Norwegian government. Other projects involve oil fields, like those at Weyburn, Saskatchewan, where operators pump carbon dioxide back underground as part of efforts to extract hard-to-reach hydrocarbons in aging wells.

But existing oil and gas wells might only be able to accommodate a few decades worth of carbon dioxide. Offshore aquifers, even though they are vast, would require enormous lengths of pipeline to carry carbon dioxide out to sea.

"Putting CO2 offshore has the obvious advantage of public acceptability," said Jeff Chapman, chief executive of the Carbon Capture & Storage Association in London.

"But we know that there are centuries worth of space for storage onshore," he said, citing examples of promising sites in China, Germany, Poland and the United States.

Schilling's three-year experiment, called CO2Sink, makes Ketzin an important test of whether carbon dioxide might safely and durably be buried inland, where underground storage space could be almost endless. It involves pumping 100 tons of the gas each day into the sandstone beneath this flat Brandenburg countryside and monitoring the ecosystem for adverse results.

If the carbon dioxide stays put, as Schilling expects, that would give a major boost to carbon capture and sequestration, or CCS, an emerging technology that would allow industries based on fossil fuels to meet stringent emissions requirements - and stay in business for decades.

"I won't say it's not dangerous, but it's less dangerous than people think," Schilling said. Ketzin, he added, could be "writing a piece of history."

Shell, Vattenfall, E.ON, Statoil and RWE are contributing money and expertise to the project, which is overseen by the National Research Center for Geosciences in Germany, Schilling said. But he said that the bulk of total financing, about €30 million, or $41.5 million, comes from the European Union and Germany, which is heavily dependent on burning coal for its electricity and where the government faces widespread opposition to nuclear power, the main alternative to coal.

Some environmentalists favor the technology because it might be the only way to control carbon dioxide emissions at a time when developing countries like China are burning ever-greater amounts of coal to fuel their booming economies.

"The growth of coal plants is absolutely scary," said Sanjeev Kumar, a carbon emissions expert with the environmental group WWF in Brussels. "If we can make fossil fuels as green as we can, then we should try to get carbon capture and storage to work on a global level."

EU policy makers still are considering whether to make it mandatory for all new coal plants to incorporate the new, cleaner technologies after 2020.

That is not fast enough for Kumar, who is lobbying for an immediate moratorium on new coal plants in Europe unless they are constructed so that carbon dioxide technology can be incorporated as soon as it becomes available.

But a number of environmentalists are concerned that further development of the technology for commercial use will simply encourage industries and governments to rely more heavily on coal. They argue that funding should be channeled into the development of renewable energies rather than on prolonging the use of fossil fuels and accumulating vast amounts of underground waste.

"You've got to consider the load on future generations to take care of these storage sites," said Gabriela von Goerne, a climate campaigner for Greenpeace in Germany. "We believe this technology does not solve our problems at all."

Environmentalists said they were also skeptical that the new technology made underground carbon dioxide storage secure. One potential hazard is that concentrated carbon dioxide is heavier than air. Large quantities of escaped gas have, in the past, settled in low-lying areas with tragic results.

In 1986, about 1,800 people were suffocated at Lake Nyos, Cameroon, when a massive cloud of carbon dioxide escaped from the formerly volcanic site. Environmentalists have warned of similar dangers if leakages occur and gas settles in dips and valleys, where people live.

Leaks from carefully selected storage sites, properly monitored, would not carry those same risks, backers of the technology say.

"If CO2 ever does get to the surface, it's not going to be in our lifetimes or much of our near-descendants' lifetimes," said Chapman of Carbon Capture & Storage Association.

At the CO2Sink project, Schilling said he expected only about 1 percent of the 60,000 tons of carbon that is to be buried at Ketzin over the next three years to escape over the next century, and about at most 5 percent over the next millennium - amounts he said would be benign.

Any leaks would be most likely to occur at the bore hole, but around-the-clock monitoring would ensure problems are quickly fixed, he said. The carbon dioxide used in the experiment will be provided by Linde, which provides gas for carbonated beverages.

But people who live in and around Ketzin are worried about having carbon dioxide stored directly underneath their feet. The latest effort to bury gas in the neighborhood reminds many residents of environmental sacrifices already made in the name of industrial progress. During the mid-1960s, leaks of carbon monoxide from a former underground gas storage site at Ketzin required the permanent evacuation of a nearby village, Knoblauch.

"They already have a garbage factory in Ketzin and now this as well," said Beatrice Görtz, 35, who lives with her toddler, Mia, in Neu Falkenrehde, a hamlet two kilometers from the injection site. "I can't imagine that it's positive."

Among experts, there are growing concerns that public opinion could turn against the technology in the same way it did against nuclear power and genetically modified foods.

David Reiner, a lecturer in technology policy at Judge Business School at Cambridge University who has coordinated public opinion polls on carbon storage in six countries, said that if the public remained in the dark about the way carbon storage was supposed to work, there was no way of knowing how they would react to wide-scale development.

"Many people have an initial negative impression," he said, "although once they learn more we tend to see a more positive inclination."