CO2 Compression Subsystem
The fact that sorbent materials have a varying affinity for sorbed species that varies as a function
of environmental conditions (e.g., temperature and pressure) is the basis of a CO2 thermochemical
compression device. For example, selective adsorbents tend to have a higher capacity for the
target adsorbate species (e.g., CO2) at lower temepratures. Therefore, thermal cycles in which the
sorbent is cooled during adsorption and heated during desorption are a means to capture CO2
from Mars at a low partial pressure (~0.8 kPa) and subsequently release it at a higher pressure
(100 kPa) and concentration for downstream processing in ISPP reactors. This is a thermal-swing
adsorption (TSA) thermochemical compression process.
Two approaches to CO2 compression using microchannel devices were developed as part of this
work, CO2 absorption and CO2 adsorption: