Ultrasonic Desorption from an Ionic Liquid Loop for Continuously Regenerable CO2 Removal from Spacecraft Cabin Atmospheres
Conference Proceeding
Overview
abstract
The CO2 Environmental Removal for Extended-duration; Spaceflight (CERES) student team at the University of; Colorado Boulder uses ionic liquid (IL)-based concepts for; regenerable CO2 removal from simulated cabin atmospheres.; The process described here utilizes an ionic liquid loop to; connect the absorption and desorption modules that together; form a closed loop continuously regenerative system. The; first module, the “absorber”, is a hollow-fiber membrane; contactor used to provide a contacting surface between a; CO2-laden atmosphere stream and the flowing IL. The IL; absorbs CO2 from the cabin atmosphere stream. The CO2-rich; IL flows into a custom flat-plate “desorber” module to; extract CO2. A vacuum pump creates a negative pressure; differential in the headspace of the desorber with respect; to the partial pressure of absorbed CO2 (ppCO2). In; combination with negative pressure, an ultrasonic; transducer attached to the desorber module is used to; enhance the desorption of weakly bonded CO2 from the ionic; liquid. Once the CO2 is expelled from the system, the; regenerated IL loops back to the absorber module for; continuous CO2 removal. Through testing, data showed that; the system was effectively absorbing and desorbing CO2,; demonstrating the function of the system. However, a; software failure of the ultrasonic system prevented the; investigation of ultrasonic desorption, which will remain; the focus of future work. Here, we present our system; design and report the results from experiments to; characterize the CO2 transport rate under varying; conditions of cabin atmosphere CO2 concentration,; atmosphere, and ionic liquid flow rates.
