Intensification of CO2 removal from low partial pressure streams coupling gas permeation and membrane contactors

Abstract

CO2 accumulation in the atmosphere of Itinerant Confined Spaces (ICS) is critical for crew safety because it can affect their cognition if CO2 concentration exceeds certain limits. The development of a national process for CO2 removal enables technological independence, and the major challenge is to remove CO2 at low partial pressures. Process simulations revealed that the coupling of gas permeation and the membrane contactor enhanced CO2 removal, which was reflected in a smaller membrane area. The simulation also provided operational curves correlating the membrane transport properties (permeance and selectivity) with the membrane area, which are important for guiding gas permeation membrane development due to the identified lack of commercial membranes. Amine-functionalized microgels, exhibiting 100 GPU for CO2 and 50 GPU for CO2/N2 selectivity, were fabricated using a spray coater. The microgels were continuously produced in a laminar flow reactor, allowing for the scale-up of the synthesis. The equipment volume was conservatively estimated at 11.6 m³ when correlating the properties of the best-synthesized membrane with the simulation results. This thesis contributes to the development of a CO2 removal process for ICS.