Browsing by Author "Teicheira, Michael"
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Item Nanoporous Silica as a Regenerable Sorbent for Potential Integration into NASA's Trace Contamination Control System(2023 International Conference on Environmental Systems, 2023-07-16) Materer, Nicholas; Kadossov, Evgueni; Apblett, Allen; Shaikh, Shoaib; Komarneni, Mallikharjuna; Teicheira, Michael; Chullen, Cinda; Boom, Kelsey; Hostetler, JohnDevelopment is underway for the next generation of spacesuits called the Extra-Vehicular Mobility Unit (xEMU). The Exploration Portable Life Support Subsystem (xPLSS) is a vitally important component of the xEMU that is also being developed. The xPLSS is tasked with the maintenance of a breathable atmosphere that is free of noxious volatile molecular species. The purification system that removes contaminants present in the ventilation system is the Trace Contamination Control System (TCC) which is a component in the ventilation loop of the xPLSS. Acid-impregnated activated carbon is the current state of the art for trace contamination control. As this sorbent is non-regenerable consumable, there is a significant impact of logistics on future missions. The primary trace contaminants that must be removed by the sorbent include ammonia, carbon monoxide, formaldehyde, and methyl mercaptan. XploSafe has developed and demonstrated the technical feasibility of a vacuum-regenerable sorbent that could be integrated into the TCC. XploSafe's sorbent media was exposed to 7-day Spacecraft Maximum Allowable Concentrations of the 18 trace contaminants that are present within the xPLSS breathing loop. The trace contaminants were exposed to the sorbent columns individually and in mixtures at relative humidities of 40% and 85% and temperature of 22 C). Adsorption breakthrough volumes and capacities were measured along with regeneration capacity for the sorbent tested with these trace contaminant analytes. Prototype TCC holder design considerations including the required sorbent mass and sorbent holder volume are also discussed.Item Test Bed for Evaluation of Sorbents Used in the Exploration Portable Life Support System(2023 International Conference on Environmental Systems, 2023-07-16) Materer, Nicholas; Kadossov, Evgueni; Apblett, Allen; Shaikh, Shoaib; Komarneni, Mallikharjuna; Teicheira, Michael; Chullen, Cinda; Bloom, KelseyThe Trace Contamination Control (TCC) system is a component in the oxygen ventilation loop of the Exploration Portable Life Support System (xPLSS) which removes contaminants generated by the crewmembers' metabolic processes. XploSafe has developed a vacuum regenerable nanoporous silica sorbent for the TCC system to advance xPLSS technology, resulting in increased mission capability, durability, and extensibility. To investigate the effectiveness of our silica-based nanoporous regenerable sorbent, XploSafe constructed a recirculating test bed that mimics the environment within the xPLSS by providing the concentrations of the trace contaminant analytes at the operating temperature, humidity, pressure and flow rates of the xPLSS. The system uses quick connect flanges and a bypass loop to allow quick removal and replacement of sorbent beds without having to purge the trace contaminant gas stream. In addition, two minutes or longer pressure swing cycles across the TCC sorbent bed can be programed. Contaminant removal efficiency across the sorbent beds is quantified by periodically measuring gas concentrations in the circulated stream using an automated sampling loop which incorporates a combination of real-time sensors and a vapor capture system connected to a thermal desorption unit combined with a gas chromatograph/mass spectrometer to separate and analyze contaminates for near real-time quantification. By monitoring the decrease in contaminant contents with time, the sorption capacity and rate constant of the evaluated sorbent medias can be determined and compared. This system will be used to test individual sorbent columns or fully assembled TCC units with the currently deployed nonregenerable sorbent or our regenerable sorbent media.Item Trace Contaminant Control Test Bed for Evaluation of TCC Prototypes with Vacuum Regenerable and Non-Regenerable Sorbents(2024 International Conference on Environmnetal Systems, 2024-07-21) Materer, Nicholas; Kadossov, Evgueni; Tidwell, John; Teicheira, Michael; Shaikh, Shoaib; Chullen, CindaAs a new Space Suit Exploration Portable Life Support System (xPLSS) is being designed, built, integrated, and tested into the Extravehicular Mobility Unit (xEMU) Design, Verification, and Test. The Trace Contaminant Control (TCC) system is a component in the oxygen ventilation loop of xPLSS that removes contaminants generated by the crewmembers� metabolic processes. The primary trace contaminants that must be removed include ammonia (NH3), carbon monoxide (CO), formaldehyde (CH2O), and methyl mercaptan (CH3SH). The current state-of-the-art TCC sorbent is non-regenerable activated carbon. As a non-regenerable sorbent, its use negatively impacts the logistics for future missions. Thus, an ideal solution can be a vacuum-regenerable sorbent integrated with the xPLSS CO2/H2O removal system. To this end, XploSafe has constructed a recirculating test bed that mimics the environment within the xPLSS by providing concentrations of the trace contaminant analytes generated at the operating temperature, humidity, pressure, and flow rates of the xPLSS. This system performs regeneration or desorption by exposing the sorbent to a pressure swing from 4.3 psia to <1 torr over approximately 2 minutes. XploSafe evaluated a vacuum regenerable and several non-regenerable sorbents within the flow loop with and without regeneration to demonstrate the operational effectiveness of these sorbents in maintaining the concentrations of the trace contaminant analytes below the 7-day Spacecraft Maximum Allowable Concentrations. Trade names are used in this presentation for identification only. Their usage does not constitute an official endorsement, either expressed or implied, by the National Aeronautics and Space Administration.Item Xplo-SA9T: Optimization of Sorbent Technology With Existing and New Amine Variants for Carbon Dioxide Removal and Humidity Control(2024 International Conference on Environmnetal Systems, 2024-07-21) Tidwell, John; Materer, Nicholas; Kadossov, Evgueni; Anderson, Hanna; Brown, Zachary; Teicheira, Michael; Shaikh, Shoaib; Apblett, AllenScrubbing of the spacesuit air stream to control humidity and regulate carbon dioxide (CO2) relies on amine-loaded resins, colloquially known as sorbents. The efficacy of Rapid Cycle Amine technology relies on the propensity of nitrogens toward adsorption of CO2 while simultaneously offering regenerative properties under vacuum or positive pressure. The commonly utilized sorbent, SA9T, was recreated and evaluated further to increase stability and serve as a benchmark comparison for newly synthesized amine sorbent technologies. Ongoing storage studies with eight different environments will allow the development of applicable storage protocols and provide insight into possible ammonia generation pathways. Attempts to alleviate the known issues with SA9T included the alteration of the primary amine (tetraethylenepentamine), the choice of resin, and the particle size distribution. In-house CO2 breakthrough experiments were conducted using a specialized apparatus that can simulate spacesuit conditions, offering high-quality triplicate capacity analysis affording direct comparison to known adsorbents in the literature. Thermo-Desorption Gas Chromatography Mass Spectrometry studies on the synthesized materials revealed any reagent or solvent off-gassing while Nuclear Magnetic Resonance spectroscopy tracked the stability of the bound amine. Scanning Electron Microscope images of sieved materials provided a more accurate size interpretation facilitating synthetic design and pressure drop elimination. All efficient sorbents were synthesized to a commercial scale subsequent to sufficient testing including Xplo-SA9T.