Capturing carbon dioxide from ambient air: A feasibility assessment

n order to mitigate climate change, deep reductions in CO2 emissions will be required in the coming decades. Carbon capture and storage will likely play an important role in these reductions. As a compliment to capturing CO2 from point sources, CO2 can be captured from ambient air ("air capture"), offsetting emissions from distributed sources or reducing atmospheric concentrations when emissions have already been constrained. In this thesis, we show that CO2 capture from air is physically and thermodynamically feasible, discuss the various routes available, and explain why NaOH solution is a viable sorbent for large-scale capture. An example system using NaOH spray is presented. With experimental data and a variety of numerical techniques, the use of NaOH spray for air capture is assessed and an example contacting system developed. The cost and energy requirements of the example contacting system are estimated. Contactor estimates are combined with estimates from industry and other research to estimate the cost of a complete air capture system. We find that the cost of capturing CO2 with the complete system would fall between 80 and 250...