16 September 2009

Carbon capture accord reached in U.K.

ConocoPhilips and U.K. coal producer Powerfuel plc reached a carbon capture and storage (CCS) deal for the depleted Viking gas field off the east coast of England.

The deal paves the way for carbon captured from Powerfuel’s proposed 900-megawatt (MW) coal-fired integrated gas combined cycle plant in Hatfield, South Yorkshire, to be stored deep under the seabed.

The agreement falls in line with a U.K. government plan to create regional clusters of power plants with CCS, shared pipelines, and storage sites. The Viking field is also a preferred storage site for another plant.

The Yorkshire region is a net exporter of electricity and has a high concentration of thermal power plants.

Adoption of CCS technologies has potential to be a significant contributor to the energy infrastructure changes required to stabilize carbon dioxide (CO₂) concentrations in an effort to slow down global warming.

In CCS operations, CO₂ separates from the fuel and then captured either before or after the combustion of coal. The user then compresses it to a super critical liquid, transports it by pipeline to an injection well, and then pumps it underground to depths sufficient to maintain critical temperatures and pressures. The CO₂ seeps into the pore spaces in the surrounding rock and its escape to the surface remains blocked by a caprock, or overlaying impermeable layer.

Energy companies boast extensive experience sequestering CO₂ by injecting it into oil fields to enhance oil recovery. Experts hope this practice can occur in saline aquifers and other geologic formations that are likely to constitute the main storage reservoirs for CO₂ emitted from coal power plants.

For related information, go to www.isa.org/productivity.