World Energy Outlook 2007

Box 5.4: Major CO 2
Capture and Storage Projects
There are at present three large-scale CCS projects in operation around
the world, each involving around 1 Mt of CO 2
per year: Sleipner in
Norway, Weyburn in Canada and the United States, and In Salah in
Algeria. A fourth project, at the Snøhvit gasfield in Norway, is due to
begin operation at the end of 2007. In addition to these projects in the oil
and gas sector, around 20 other major projects in the power sector have
been announced.
In the off-shore Sleipner project, which began operation in 1996, CO 2
is
separated from produced natural gas and injected into a saline aquifer.
Over 1 Mt per year has so far been stored and a total of 20 Mt is expected
to be stored during the life of the project. Extensive monitoring, to track
the dispersion of CO 2
in the aquifer, has been carried out, including the
use of 4-D seismic techniques.
The Weyburn project involves the capture of over 1.7 Mt per year of CO 2
in a coal-gasification plant in North Dakota in the United States. The gas
is compressed and transported via a 330-km pipeline to EnCana’s
Weyburn field in Saskatchewan in Canada, where it is used for enhanced
oil recovery. Injection, which started in 2000, is expected to boost
cumulative oil output by over 120 million barrels.
Like Sleipner, the gas produced at the In Salah (and neighbouring) fields
has a CO 2
content of between 4% and 9 %, which exceeds the permitted
amount in sales contracts. A processing plant at Krechba uses a chemical
solvent to separate out the CO 2
from the gas produced. Four compression
stages are then used to pressurise CO 2
and inject it into a 20 metre-thick
reservoir, which lies under the gas-producing zone. Storage capacity is
1 Mt of CO 2
per year. A total of 17 Mt is expected to be stored over the
life of the project, at a cost of $6 per tonne of CO 2
(Wright, 2006).
5
At present, there are limited financial incentives for operators of power stations
or large industrial facilities to install CCS. But this may change in the future.
For this reason, and because power plants have very long lives (typically over
40 years), the IEA is investigating the possibility of making power plants
“CCS-ready” as part of the Agency’s G8 Gleneagles Plan of Action (IEA-GHG,
2007). The aim is to lower the cost of retrofitting existing plants. At present,
the total cost of CCS is estimated at between $66 and $122/tonne of CO 2
for
a retrofit of a coal-fired pulverised coal plant (WEC, 2006). Retrofit costs are
expected to fall as operational experience grows and technology improves, and
with the introduction of CCS-ready plants.
Chapter 5 - Global Environmental Repercussions 219