[caption id="attachment_111829" align="alignright" width="300" caption="Diagram showing both terrestrial and geological capture and storage of carbon dioxide emissions from a coal-fired plant."]
Over the years, scientists have published countless research reports on methods to reduce greenhouse gas emissions. But what about doing something with the emissions are currently being created? One proposal in the fight against global warming is carbon capture and storage (CCS). Last week, the North American Carbon Capture & Storage Atlas (NACCSA
), a joint effort between U.S., Canadian and Mexican governments, created the first ever document mapping the underground storage potential of the continent. According to NACCSA, North America has the potential to store carbon emissions for at least 500 years.
How CCS works
Carbon capture and storage technology involves the injection of industrial emissions of carbon dioxide (CO2) into suitable geologic reservoirs for the purposes of either long-term storage or energy recovery. Various technologies already exist and more are being developed to enable the capture of CO2 from industrial facilities. Once the CO2 has been captured, and depending upon the source, the gas is compressed and transported via pipeline to the injection well. The CO2 enters the subsurface as a liquid where it (hopefully) remains confined.
The US and Canada are also exploring the opportunities for enhanced oil recovery (EOR). Enhanced oil recovery employs a technique where the captured CO2 is used to tap hard-to-access reserves and improve the business case for installing the highly expensive technology. If the CO2 is used for enhanced oil recovery, the gas is recycled in a closed system, which likewise results in the carbon dioxide being stored in the reservoir.
The idea has not been widely explored outside the US, although one UK developer, 2CO
, is looking to link its proposed Don Valley Power Project in Yorkshire to oil fields in the North Sea in order to undertake EOR, which would mark the first time the approach has been attempted offshore.
What this means for the planet
The Intergovernmental Panel on Climate Change (IPCC
) recognized the following benefits of successful carbon capture and storage:
- CCS technologies have the potential to reduce overall climate change mitigation costs and increase flexibility in reducing greenhouse gas emissions (GHG).
- A CCS-equipped power plant could reduce CO2 emissions by approximately 80-90 percent compared to a plant without CCS.
- The application of CCS technologies in GHG mitigation portfolios could reduce the costs of stabilizing CO2 concentrations in the atmosphere by 30 percent or more compared to scenarios where CCS technologies are not deployed.
- The component parts of CCS (capture, transportation and storage) can utilize technologies adapted from other commercial industries, enhancing the availability and cost competitiveness of CCS technologies as viable mitigation options.
- It is likely that well-selected, well-designed and well-managed sites can sequester CO2 for long periods of time and safely, as carbon dioxide has been retained in geologic formations through natural processes for hundreds of millions of years.
The Global Energy Technology Strategy Program (GTSP
) has identified the following benefits associated with CCS over time:
- Near-term: CCS will allow many industries such as electricity generation, refining, chemical production, and steel and cement manufacturing to project a feasible path into a carbon-constrained world.
- Medium-term: CCS will facilitate a smoother transition of the global economy to a low GHG emissions future.
- Long-term: CCS will make valuable commodities like electricity and hydrogen cheaper than they would be if such technologies were not available.
As promising as this technology sounds it is largely unproven for both large-scale and long-term use. The underground storage systems will only work to mitigate climate change if the carbon actually stays put. To date, there have not been sufficient studies to demonstrate that it will - especially given that the storage needs to be effectively permanent in order to protect the earth from global warming. Nevertheless, it's a technology that certainly merits further study and consideration, given the scale of potential benefits.
As U.S. Energy Secretary Steven Chu said
,"This new atlas provides the kind of fundamental information that, combined with technological innovation, can help fossil-fueled facilities continue their essential energy role while reducing carbon pollution.”
Photo courtesy of Wikipedia.