"CO2 capture from ambient air: An example system"
Joshuah K. Stolaroff, Greg V. Lowry & David W. Keith
In order to mitigate climate change, deep reductions in CO2 emissions
will be required in the coming decades. Carbon capture and storage will
likely play a large role in these reductions. As a compliment to
capturing CO2 from point sources, CO2 can be captured from ambient air,
offsetting emissions from distributed sources. In this paper, 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 sorbant for largescale capture. An example system using NaOH
spray is presented. With experimental data and a variety of numerical
techniques, the mass transfer of CO2 to falling drops of NaOH solution
is calculated, and an example contacting system developed. The cost and
energy requirements of the contacting system are estimated and combined
with estimates from industry and other research to estimate the cost of
the complete system. We find that the cost of capturing CO2 with the
complete system would fall between 240 and 550 $/t-C, and improvements
are suggested which could reduce the cost by about 100 $/t-C from the
upper bound. Policy implications of this result are discussed.
PDF's are password protected. If you're a first-time
visitor and need a password, please click here.