Advanced Supported Liquid Membranes for CO2 Control in EVA Applications

Ionic-Liquid-Based Contactors for Carbon Dioxide Removal from Simulated Spacecraft Cabin Atmospheres

“…Imidazolium-based ILs have shown high selectivity for CO 2 sorption over nitrogen and oxygen (depending on the nature of the anion and/or functional groups), allowing them to selectively uptake CO 2 without drastically changing the remaining gas composition whether for revitalization of spacecraft atmospheres [20]- [23], [36]- [41], control of greenhouse gas emissions [42]- [48], or natural gas treatment [49]- [50]. The RTIL, 1-butyl-3-methylimidazolium acetate [bmim][Ac] (Fig.…”

“…RTILs can continually remove CO 2 from spacecraft and spacesuit atmospheres when used in a supported ionic liquid membrane [20]- [23] or direct liquid contactor [36]- [41] given subsequent removal from the permeate flow to maintain a difference in partial pressures, the driving potential for gas transport. Membrane supports can be either organic (polymeric) or inorganic (ceramic or metallic), porous or non-porous.…”

“…Several regenerable sorbent materials have been researched for CO 2 removal from space habitat atmospheres, which include zeolite-coated Microlith mesh substrates [13], zeolite sorbent materials [3]- [6], [13]- [15], liquid and solid amines [16]- [17], and ionic liquids [18]. Implementations for treatment of spacecraft cabin or spacesuit atmospheres include the CO 2 Removal and Compression System (CRCS) [19], the CO 2 And Moisture Removal Amine Swing-bed (CAMRAS) [16], the Rapid Cycling Amine (RCA) system [17], Supported Ionic Liquid Membranes (SILMs) [20]- [23], and water walls, a novel passive concept in which a supported water wall absorbs gases from the I cabin atmosphere for provision to algae [24]. Each of these sorbents are described below.…”

Ionic Liquids in Space Technology – Current and Future Trends

“…The same principles can be applied to the removal of CO 2 from cabin air in a spacecraft, lunar habitation unit, or in the primary life support system (PLSS) in an astronaut's spacesuit. Recent work, funded by NASA, has led to the invention and patenting of supported IL membrane (SILM) technology for use in CO 2 control in extravehicular activities (EVA) relating to future Moon or Mars human missions . The goal of this invention is to facilitate longer EVAs, without increasing the size and weight of the PLSS.…”

Facilitated transport membrane with functionalized ionic liquid carriers for CO2/N2, CO2/O2, and CO2/air separations

“…48 While FTMs have been studied for CO 2 separation from post-combustion flue gas, there are only a few reports that we are aware of discussing their utility relevant for DAC and for CO 2 removal from cabin air. [49][50][51] Under DAC and cabin air conditions, there is very small driving force for CO 2 transport owing to low concentration, temperature, and humidity; hence, it is extremely challenging to concentrate the CO 2 on the effluent side. There has been two reports assessing mem-brane-based DAC processes by simulations based on (1) a hypothetical non-FTM 52 with ultra-high permeance (40 000 GPU) and low CO 2 /N 2 selectivity (70); and (2) a hypothetical FTM 53 with high permeance (2500 GPU) and high CO 2 /N 2 selectivity (680).…”