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Giesy, Timothy J.

Publications and source records attributed to Giesy, Timothy J..

Virtual Design of a 4-Bed Molecular Sieve for Exploration

Simulations of six new 4-Bed Molecular Sieve configurations have been performed using a COMSOL (COMSOL Multiphysics - commercial software) model. The preliminary results show that reductions in desiccant bed size and sorbent bed size when compared to the International Space Station configuration are feasible while still yielding a process that handles at least 4.0 kilograms a day CO2. The results also show that changes to the CO2 sorbent are likewise feasible. Decreasing the bed sizes was found to have very little negative effect on the adsorption process; breakthrough of CO2 in the sorbent bed was observed for two of the configurations, but a small degree of CO2 breakthrough is acceptable, and water breakthrough in the desiccant beds was not observed. Both configurations for which CO2 breakthrough was observed still yield relatively high CO2 efficiency, and future investigations will focus on bed size in order to find the optimum configuration.

Giesy, Timothy J.↗

Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017

NASA has embarked on the mission to enable humans to explore deep space, including the goal of sending humans to Mars. This journey will require significant developments in a wide range of technical areas as resupply and early return are not possible. Additionally, mass, power, and volume must be minimized for all phases to maximize propulsion availability. Among the critical areas identified for development are life support systems, which will require increases in reliability as well as reduce resource usage. Two primary points for reliability are the mechanical stability of sorbent pellets and recovery of CO2 sorbent productivity after off-nominal events. In this paper, we discuss the present efforts towards screening and characterizing commercially-available sorbents for extended operation in desiccant and CO2 removal beds. With minimized dusting as the primary criteria, a commercial 13X zeolite was selected and tested for performance and risk.

Knox, James C.↗

Virtual Design of a 4-Bed Molecular Sieve for Exploration

Simulations of six new 4-Bed Molecular Sieve configurations have been performed using a COMSOL model. The preliminary results show that reductions in desiccant bed size and sorbent bed size when compared to the International Space Station configuration are feasible while still yielding a process that handles at least 4.0 kg/day CO2. The results also show that changes to the CO2 sorbent are likewise feasible. Decreasing the bed sizes was found to have very little negative effect on the adsorption process; breakthrough of CO2 in the sorbent bed was observed for two of the configurations, but water breakthrough in the desiccant beds was not observed. Nevertheless, both configurations for which CO2 breakthrough was observed still yield relatively high CO2 efficiency, and future investigations will focus on bed size in order to find the optimum configuration.

Giesy, Timothy J.↗