The American Physical Society (APS) has published its new appraisal on technical features of Direct Air Capture (DAC) of Carbon Dioxide from the atmosphere with chemicals for the benefit of the scientific fraternity.
The appraisal is the result of a two-year research performed by a 13-member group comprising people from academia, national and government labs and members from the industry. DAC currently has a restricted part in climate change policy discussions because it happens to be one among the alternatives available to cut down the level of carbon dioxide from the atmosphere
In the DAC systems when ambient air runs over a liquid or solid sorbent material it selectively removes the carbon dioxide and the carbon dioxide is then discharged as a concentrated flow for reuse or removal. The sorbent material is then reclaimed and the cleaned air is released to the atmosphere. During the appraisal it was found that the use of a standard DAC system for the removal of carbon dioxide costs seven or more times more than an ordinary system utilized in coal power plants for the removal carbon dioxide from flue gas. The estimated cost of removing one ton of carbon dioxide by utilizing a DAC system was found to be around $600 where as the post-combustion capture of one ton of carbon dioxide from flue gas was costing only $80.
The appraisal estimates that the use of DAC may come into spotlight only when the carbon dioxide discharges from more carbon concentrated sources such as natural gas or coal power plants are removed either by the use of non-fossil fuels or by using means to detain all the carbon dioxide emissions. The report states that ambient air contains 300 times more diluted carbon dioxide than it is released from gas or coal plants.
The report adds that on the use of DAC, only a few trial reports are available and neither a demo project nor pilot-scale DAC systems have taken place. It suggests that only a range of engineering and scientific issues will resolve the viability and cost- effectiveness of deploying DAC. It concludes that DAC will play a notable role in the removal of carbon dioxide from the atmosphere only when the cost of its use comes much below that of a comparable standard system. The members have concluded that for a number of decades DAC will assume a limited part in lessening the intensity of carbon dioxide.
Source: http://www.aps.org/