Cryogenic CO_2 Capture to Control Climate Change Emissions

摘要

An innovative CO_2 capture technology called the cryogenic CO_2 capture (CCC) process has significant energy and cost advantages compared to alternatives. The process is a post-combustion technology that cools CO_2-laden flue gas to desublimation temperatures (-100 to -135°C), separates solid CO_2 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 CO_2 to final pressures (100-200 atm), and delivers a compressed CO_2 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, SO_x, NO_2, 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.