German researchers look for ways to store carbon dioxide
A Norwegian oil company is storing unwanted carbon dioxide 1,000 metres under the sea bed. German researchers are now
taking a closer look at this method to reduce the emission of carbons in the atmosphere.
Carbon dioxide is a potential time bomb, capable of wreaking global havoc. Warding it off requires concerted global action, economic sacrifice and innovative ideas. But experts agree that so far, not enough has been done to avoid continuous global warming.
One safe, and viable option for reducing carbon dioxide in the atmosphere is deep sea storage of this environmentally
harmful gas. The first European country to have tried this option is the Norwegian oil company Statoil.
Around 2,800 tons of carbon dioxide -- just about the same amount emitted by 1600 cars driving from Lissabon to Istanbul -- are created daily as a by-product at Statoil’s North Sea gas field in Sleipner. In order to avoid carbon dioxide reaching the atmosphere, Statoil pumps them down a pipeline some 1,000 metres under sea level.
Here, a sandstone formation seeps up the gas, which dissolves in the salty seawater collected in the sandstone’s pores. Six hundred billion tons of carbon dioxide could be stored in this formation, according to Statoil. In addition, if Statoil emitted the 600 bn tons of carbon into the atmosphere, it would have to pay more than EUR 49 mm ($ 48.36) in carbon dioxide taxes. This year, Statoil will save EUR 4 mm alone in taxes, even though, it says, converting to these disposal methods leads to a cost rise of 50-80 %.
Statoil began its saline aquifer carbon dioxide storage (Sacs) project, which is funded by the European Commission,
back in 1996.
"The core of Sacs’ work has been to arrive at a reasoned view of whether carbon dioxide remains in the Itsira sand", Norwegian project manager Tore A. Torp says. The first results of close research were revealed in 2000 -- and proved that the formation is unlikely to leak for the next several hundred years.
According to Torp, the formationmay not be "carbon-tight" for ever. But a duration until the next age, in 5–10,000 years, must be good enough, he says.
The project in Norway is unique in Europe. But carbon dioxide could easily be stored in Germany too -- both under
water or under the earth. According to Dr Peter Gehrling from the Federal Association of Geoscience and Resources in
Hanover, "we are thinking primarily of exhausted oil fields and on underwater so called aquifers (sandstone
formations)". But also former nuclear plants or cement ovens could be turned into future carbon dioxide
Germany’s former oil fields would theoretically be able to store the complete carbon emission of the German industry -- however, only for six years. In Aachen, German scientists are researching the potentials of various stone types to store carbon. The research consists largely of cutting off thick slices of rock and testing their resistance to air pressure and temperature resembling that in a potential carbon-saving stone formation.
How long the potential carbon banks need to be able to store the gas, has not yet been decided by German authorities.
"On the one hand the lawmakers are expected to set guidelines, similar to the disposal of nuclear waste, which is
around 10,000 years. On the other hand, natural carbon disposal sites exist for up to several million years".
Therefore, he says, he is sure that carbon dioxide can stay for similar periods of time underground.
For Norwegian Tore A. Torp, however, the future of carbon storage lies in future financial support. "This approach isn’t the first people are likely to turn to, but it will be one of the key solutions if emission reductions are really going to bite", he says. He believes the injection method will first be adopted when an international tax system makes it attractive for energy producers to remove carbon dioxide and harder for customers to buy cheaper, greater polluting power.