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Capture of dilute COâ‚‚ directly from the air at 450 parts per million requires more than three times the amount of energy than capture of concentrated COâ‚‚ from an industrial furnace or power plant. So how can it be justified?

Direct air capture can be practiced virtually anywhere, including geologic storage sites or facilities where COâ‚‚ is converted to fuels or chemicals. Pipelines to storage, use, or conversion facilities are not required. Geologic storage results in long-term negative emissions or a reduction in atmospheric COâ‚‚ concentrations, which is attractive to many stakeholders for managing our complex energy system.

COâ‚‚ purity is typically greater than that captured from fossil point source locations. If we use COâ‚‚ captured from the air with renewable energy to make a synthetic jet fuel, then combustion of the fuel during use results in a circular pathway: there are no new fossil COâ‚‚ emissions. One does not have to consider whether the COâ‚‚ used results in a displacement of fossil fuel use, in order to assess impact.

Direct air capture provides a pathway for offering options to consumers for purchasing products or credible offsets to reduce their greenhouse gas emissions, should they so choose.

Figure ET-25: Direct Air Capture of Carbon Dioxide [1]

 
Reference

Wilcox et al., World Resources Institute.