Storing up benefits

26/10/2007 Carbon storage could help to solve the world’s climate problems. But establishing this industry is a matter of urgency, believes Danish scientist Niels Peter Christensen.

Text: Ina Gundersen, Photo: Ole Christiansen

Putting carbon dioxide out of harm’s way may become a major industry, says Mr Christensen, a geologist and chief consultant at the Geological Survey of Denmark and Greenland (Geus).

Some 24 billion tonnes of this greenhouse gas are released every year, with 40-60 per cent coming from large point sources such as power stations or heavy industry. These emissions could be avoided through sub-surface storage.

One possibility is to use carbon dioxide for improved oil recovery (IOR) in offshore fields. Injecting the gas into producing reservoirs could force out more crude.


Niels Peter Christensen
Some 24 billion tonnes of carbon dioxide are released to the air annually. As one of the world’s leading specialists on carbon storage, Niels Peter Christensen believes that storage could become a major industry.

“The North Sea offers an enormous potential for injection in mature oil and gas fields,” notes Mr Christensen, one of Europe’s leading scientists in the field of carbon storage.

“An estimated five-six billion extra barrels of oil could be recovered from these reservoirs. But the work must begin fairly soon, while installations are operating. They can’t be restarted.”

The challenge is that development and transport costs could be high, particularly for possible transport of the greenhouse gas from Europe to Norwegian fields. Very large volumes are needed if carbon dioxide is to be used for improved oil recovery (IOR)

Mr Christensen played a key role when Statoil began to store carbon dioxide from the Sleipner West field in the Utsira formation beneath the North Sea during the 1990s.

In his view, this project was crucial in winning European acceptance of carbon capture and storage (CCS). He now leads the GeoCapacity research project on assessing European capacity for geological storage of carbon dioxide.

Funded by the European Union, this scientific collaboration will explore CCS opportunities in 20 of its member countries. Work on investigating prospects in China has also started.

If CCS is to make a significant contribution to reducing emissions to the air, carbon dioxide must be collected on a large scale and this work must start soon, Mr Christiansen notes.

“We’re talking about huge dimensions. To handle such volumes of the gas, we must build up an industry which could become as big as the oil business is today.

“Europe contains perhaps as many as 300-500 geological traps which can be used for carbon storage. And we’re close to a technological solution for preventing power station emissions.”

Earlier EU research projects indicate that carbon storage is possible in geological traps both offshore and on land. Northern Germany and Denmark are particularly relevant, but Britain, Norway and the Netherlands also have a big storage potential.

Studies also indicate that it could be relevant to deposit large volumes of carbon dioxide in such countries as Poland, Romania, Hungary and Slovenia.

“China is almost as large as Europe and has storage opportunities,” says Mr Christensen in a comment on the EU’s collaboration with the far eastern nation over CCS.

“In addition to investigating these possibilities, we’re working to train the Chinese in this area.” Nevertheless, CCS facilities are not particularly widespread. Several factors account for this, not least the consideration that carbon storage has a long time frame – perhaps thousands of years.

It is not easy to demonstrate that the geological traps will remain sealed for that long. If the gas escapes, it could affect the climate.

Environmental impacts can also be local. Although carbon dioxide is non-toxic, it could accumulate in cellars and holes in the ground and – in the worst case – suffocate animals and people.

While carbon capture is expensive because of its energy-intensive character, transport and storage require less energy input.

“No company will invest until a legislative framework is in place and before it is clear that carbon dioxide has a value,” says Mr Christensen.

“That could be achieved through carbon taxes or through the cost of emission allowances, which could make CCS profitable.”

Divert attention
Critics maintain that carbon management could divert attention from the need to develop renewable energy and action to reduce consumption.

Mr Christensen’s response is that every measure must be adopted to reduce greenhouse gas emissions and help to curb or halt human-induced climate changes.

Developing sufficiently renewable and environment-friendly energy takes time. In the meantime, CCS could become highly significant.

The world’s first land-based test facility opened this summer in the small town of Ketzin outside Berlin. Plans also call for a demonstration plant to be built in Denmark within two-three years.

“Ketzin’s CCS project is the first which will not only analyse the technical and financial aspects but also help to create popular acceptance and security for storage near a heavily built-up area,” says Mr Christensen.

“Experience and technology from the Sleipner area and other offshore locations are being utilised here on land.”

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Updated: 14/12/2009