MAINSTREAM ENGINEERING CORP SBIR Phase II Award, June 2023

Currently, oxygen in space is recovered through an advanced oxygen recovery system, which does not fully recover the oxygen. Future missions may use technologies such as the Plasma Pyrolysis Assembly (PPA) or Bosch process, both of which recover oxygen, but generate large amounts of carbon particulate (0.2 ndash; 50 micro;m) that must be removed for proper operation and crew safety. In Phase I, Mainstream developed and demonstrated a high-efficiency carbon removal system (CRS) to safely collect, remove, and dispose of sub-micron carbon particulates that consists of a 1st-stage cyclone separator that removes 85% of the particulate (focused towards larger particles), a 2nd-stage electrostatic precipitator that removes another 8% (focused towards small particles), and a final porous metal filter which removes the remaining ~7% for a total removal efficiency of 99.93% at 0.3 micro;m and 99.69% from 0.3 micro;m to 10 micro;m.The CRS system was designed to operate in high-temperature steam (Bosch) or hydrogen (PPA) without issues. It is lt;0.1 ft3, 4 lb, and consumes lt;20 W of power with a pressure drop of lt;50 torr including all components and electronics. Phase I culminated in a final validation of operation independent of gravity (i.e., tested upside down), high loading (gt;10 g/min), and in high-temperature steam.In Phasenbsp;II, Mainstream will iterate on the CRS prototype with our optimized computation fluid dynamics models, focus on practical carbon removal from the subsystems, and experimentally evaluate long-term CRS performance, pressure drop, and regeneration at relevant carbon loadings and operation conditions (e.g., reduced pressure, gravity, PPA, Bosch). The verified CRS undergo PPA and Bosch relevant lifetime testing and mature hardware delivered to NASA for evaluation.