Advanced Multipollutant Trace Contaminant Sorbents for the Exploration Portable Life Support System

This proposal addresses the fabrication and testing of structured (monolithic), carbon-based multipollutant trace-contaminant (TC) sorbents for the space-suit Exploration Portable Life Support System (xPLSS) used in Extravehicular Activities (EVAs). The proposed innovations: (1) multipollutant trace-contaminant control; (2) thin-walled, structured carbon TC sorbents fabricated using three-dimensional (3D) printing; and (3) the patented low-temperature oxidation step used for the treatment of carbon sorbents. The overall objective: to develop a multipollutant trace-contaminant removal system that is rapidly vacuum-regenerable and that possesses substantial weight, size, and power-requirement advantages with respect to the current state of the art. The Phase 1 project successfully demonstrated the effectiveness of monolithic carbon sorbents derived from 3D-printed PEEK polymer with respect to ammonia, formaldehyde, and methyl mercaptan removal at concentrations close to 7-day Spacecraft Maximum Allowable Concentration (SMAC) limits. The sorbent monoliths were also evaluated with respect to carbon-monoxide control, and a path to multipollutant TC control was defined for future RD. The Phase 2 objectives: (1) to optimize sorbent properties and performance; (2) to design, construct, test, and deliver to NASA two full-scale TC sorbent prototypes; (3) to integrate the full-scale TC Control System (TCCS) with the xPLSS design, and particularly with the Rapid-Cycle Amine (RCA) swing bed for CO2 control. This work will be accomplished in five tasks: (1) Sorbent Development and Optimization; (2) Subscale Sorbent Testing; (3) Full-Scale Prototype Development; (4) Full-Scale Prototype Integration with xPLSS/RCA and Testing; and (5) System Evaluation. The main focus will be full-scale TCCS development and its integration with xPLSS/RCA (Tasks 3 and 4). PROBLEM: Non-regenerable activated carbon is currently used for trace-contaminant (TC) control. prior to the Phase 1 project, our regenerable sorbents were tested at concentrations much higher than the 7-day Spacecraft Maximum Allowable Concentrations (SMAC), and mostly only for ammonia (formaldehyde, methyl mercaptan, and carbon monoxide not extensively tested, and certainly not at 7-day SMAC levels). INNOVATIONS: (1) multipollutant, simultaneous TC control at the 7-day SMAC; (2) thin-walled, structured carbon TC sorbents fabricated using three-dimensional (3D) printing; and (3) the patented low-temperature oxidation step used for the treatment of carbon sorbents. APPROACH: The development and fabrication of vacuum-regenerable, structured (monolithic), carbon-based multipollutant TC sorbents for the space suit. BENEFITS: (a) high TC sorption capacity; (b) low pressure drop; (c) rapid vacuum (pressure-swing) desorption due to thin monolith walls and low pressure drop; (d) good thermal management; and (e) good resistance to dusty environments. COMMERCIALIZATION PARTNER: Collins Aerospace OVERALL OBJECTIVES: to develop a multipollutant TC removal system that is rapidly vacuum-regenerable and that possesses substantial weight, size, and power-requirement advantages with respect to the current state of the art. A 50% reduction in weight and volume is the target, with a potential to realize even a greater benefit, without sacrificing system performance. PHASE 2 OBJECTIVES: (1) to optimize sorbent properties and performance; (2) to design, construct, and deliver to NASA JSC two full-scale prototypes; and (3) to integrate the full-scale TC Control System (TCCS) with the xPLSS design, and particularly with the Rapid-Cycle Amine (RCA) swing bed for CO2 control. PHASE 2 WORK PLAN: (1) Sorbent Development and Optimization; (2) 1/6-Scale Sorbent Testing; (3) Full-Scale Prototype Development; (4) Full-Scale Prototype Integration with xPLSS/RCA and Testing; and (5) System Evaluation. The main focus will be on full-scale TCCS development and its integration with xPLSS/RCA (Tasks 3 and 4). PHASE 2 DELIVERABLES: 2 full-scale sorbent prototypes (after 12 and after 24 months); the final report.
Benefits: The main application of the proposed technology would be in spacecraft life-support systems, mainly in extravehicular activities (space suit), but after modifications also in cabin-air revitalization. The developed technology may find applications in air-revitalization on board US Navy submarines, in commercial and military aircraft, in the future air-conditioning systems for green buildings, and in advanced scuba-diving systems.