Cryogenic CO2 Capture as a Cost-Effective CO2 Capture Process

The cryogenic CO2 capture (CCC) process appears to consume 30 % or more less energy and money than other major competing carbon capture processes. The process cools CO2-laden flue gas to desublimation temperatures (-100 to-135 °C), separates solid CO2 that forms from the flue gas from the light gases, uses the cold products to cool incoming gases in a recuperative heat exchanger, compresses the solid/liquid CO2 to final pressures (100-200 atm), and delivers a compressed CO2 stream separated from an atmospheric pressure light-gas stream. The overall energy and economic costs appear to be at least 30 % lower than most competing processes that involve air separation units (ASUs), solvents, or similar technologies. In addition, the CCC process enjoys several ancillary benefits, including (a) it is a minimally invasive bolt-on technology, (b) it provides highly efficient removal of most pollutants (Hg, SOx, NO2, HCl, etc.), (c) possible energy storage capacity, and (d) potential water savings. This paper outlines the process details and economic and energy comparisons relative to other well-documented alternatives