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Washington DC (SPX) May 10, 2011, 2011
The American Physical Society has released a new assessment - Direct Air Capture of CO2 with Chemicals - to better inform the scientific community on the technical aspects of removing carbon dioxide from the atmosphere.
In systems achieving direct air capture (DAC) of carbon dioxide (CO2), ambient air flows over a chemical sorbent, either liquid or solid, that selectively removes the CO2. The CO2 is then released as a concentrated stream for disposal or reuse, while the sorbent is regenerated and the CO2-depleted air is returned to the atmosphere.
DAC is now included in discussions of climate change policy because it is among the few strategies that might lower the atmospheric concentration of CO2 to reduce the negative impacts of climate change. However, the intent of this assessment is not to make specific policy recommendations.
The assessment is the outcome of a two-year study conducted by a 13-member committee whose members work in industry, academia, and national and government laboratories. It concludes that DAC would play a very limited role in a coherent CO2 mitigation strategy for many decades.
Deployment of DAC would not be pursued aggressively until the world has largely eliminated centralized sources of CO2 emissions, especially at coal and natural gas power plants, either by substitution of non-fossil alternatives or by capture of nearly all of their CO2 emissions.
For example, it makes little sense to ignore the emissions of CO2 in the flue gas from a coal power plant while removing CO2 from ambient air where it is 300 times more dilute.