Browsing by Author "Jan, Darrell"
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Item Air-Cooled Temperature Swing Compression System Rebuild(50th International Conference on Environmental Systems, 7/12/2021) Alcid, Marian; Gan, Kelby; Castellanos, Jonathan; Jan, Darrell; Richardson, Tra-My JustineThe Air-Cooled Temperature Swing Adsorption Compression System (AC-TSAC) was designed to be a viable alternative to the carbon dioxide (CO2) mechanical compressor currently in use on the International Space Station (ISS). The AC-TSAC would be integrated downstream of the Four-Bed Molecular Sieve (4BMS) CO2 removal system and upstream of the Sabatier reactor system. The previous generation of the AC-TSAC system was dismantled and has undergone a significant upgrade to modernize the system and resolve system failures.Item Analysis of Spacecraft Cabin Carbon Dioxide Capture via Deposition(48th International Conference on Environmental Systems, 2018-07-08) Belancik, Grace; Jan, Darrell; Huang, RogerExtended manned missions through deep space present a number of unique challenges yet to be solved before said missions are feasible. One pertinent challenge is the CO2 removal system, as the current state-of-the-art requires repeated, costly maintenance. Multiple alternative CO2 removal systems are currently being evaluated as potential successors, including solid and liquid sorbents. An alternative to sorption techniques entirely is deposition of CO2 from the cabin atmosphere onto a cold surface. Deposition provides numerous benefits, including multiple methods of generating a cold surface. Cryogenic coolers and thermal radiators are two methods that are both highly reliable. Another benefit is the ability to provide humidity and trace contaminant control, as well as CO2 storage and compression, in addition to CO2 capture. Cryogenic coolers, specifically Stirling coolers, are currently being tested for use in Martian atmosphere CO2 capture, but the work described in this paper is one of the first examinations into the application of spacecraft cabin atmosphere. After the Stirling cooler CO2 deposition system was built, a test matrix of varying inlet flow rates, CO2 concentrations, and temperature set points was completed to evaluate the system. In addition, one set of parameters was selected to ensure repeatability and determine a working cycle time. A decaying increase of CO2 removal rate with decreasing temperature was observed at all tested inlet flow rates and concentrations. Also, CO2 removal rate decayed with system run time. The data gleaned from this initial study will be used to inform a more efficient, cycling CO2 deposition system design.Item Carbon Dioxide Compression, Storage, and Delivery Trade Assessment(45th International Conference on Environmental Systems, 2015-07-12) Richardson, Tra-My Justine; Jan, Darrell; Hogan, John; Bohrer, Robert; Marson, David K.Spaceflight application requires the removal and compression/storage of carbon dioxide for delivery to the Sabatier assembly. The carbon dioxide compression, storage, and delivery technologies include the Southwest Research Institute (SwRI) mechanical compressor, the Temperature Swing Adsorption Compressor (TSAC), and the Carbon Dioxide Removal and Compression System (CRCS). The SwRI is a mechanical system whereas the TSAC and the CRCS are adsorption based. Here, a trade study using radar charts will be conducted to compare the different carbon dioxide compression and storage technologies for use with the Sabatier system.Item Characterizing Cryogenic Carbon Dioxide Capture for Life Support Systems(47th International Conference on Environmental Systems, 2017-07-16) Belancik, Grace; Jan, Darrell; Huang, Roger; Paredes-Garcia, Jordi; Chambliss, JoeWithout a vastly improved cabin air CO2 removal system technology, deep space missions will not be plausible. The carbon dioxide removal assembly (CDRA) on ISS has repeated replacement and maintenance costs due to adsorbent material degradation. A current effort to evaluate CO2 removal systems to succeed CDRA is underway. Alternative adsorption and thermal amine technologies are included. Cryogenic capture of CO2 in a cabin atmosphere is a newly-explored solution. Cryogenics are highly reliable, self-sufficient systems with great potential in this area of study. The added benefit of a cryogenic system is that it can provide humidity and trace contaminant control in addition to CO2 capture. Whereas cryogenic cooling technologies are established and Mars atmosphere CO2 capture has been tested, little research has been done on the application of cryogenic cooling to life support CO2 capture. This paper describes the design, build and initial functional testing of a lab-scale cryogenic system to remove CO2 from simulated cabin air. The system is ready to test both CO2/N2 mixed and dry CO2-loaded air, and production rate, cycle time, and power requirements will be characterized so that future flight-like system requirements may be better modeled.Item CO2 Capacity Sorbent Analysis Using Volumetric Measurement Approach(47th International Conference on Environmental Systems, 2017-07-16) Huang, Roger; Belancik, Grace; Jan, Darrell; Knox, James; Richardson, Tra-My JustineIn support of air revitalization system sorbent selection for future space missions, Ames Research Center (ARC) has performed CO2 capacity tests on various solid sorbents to complement structural strength tests conducted at Marshall Space Flight Center (MSFC). The materials of interest are: Grace Davison Grade 544 13X, Honeywell UOP APG III, LiLSX VSA-10, BASF 13X, and Grace Davison Grade 522 5A. CO2 capacity was for all sorbent materials using a Micromeritics ASAP 2020 Physisorption Volumetric Analysis machine to produce 0°C, 10°C, 25°C, 50°C, and 75°C isotherms. These data are to be used for modeling data and to provide a basis for continued sorbent research. The volumetric analysis method proved to be effective in generating consistent and repeatable data for the 13X sorbents, but the method needs to be refined to tailor to different sorbents.Item CO2 removal system for Manned Mission beyond LEO using deep space radiators and solar heaters(46th International Conference on Environmental Systems, 2016-07-10) Paredes Garcia, Jordi; Nakazono, Barry; Voecks, Gerald; Jones, Jack; Jan, Darrell; Hogan, JohnThe current spacecraft technology to remove CO2 generated in manned missions uses mostly zeolite filters, which break down relatively easy; this has caused multiple problems over the last decades. The current solution has been to replace the defective components sending replacements form Earth, but this is only viable for missions close to Earth, e.g. ISS. Once humans require longer duration missions without Earth access, highly reliable CO2 capture needs to be implemented. There is no current technology that captures CO2 levels for long duration missions. Gaseous CO2 can be captured cryogenically, and the different solidification temperatures between water, carbon dioxide, nitrogen and oxygen become the key parameters of this system. It is important to note that human generated organic contaminants freeze at higher temperature than CO2. These contaminants will be captured prior to CO2 solidification. The medical community has determined that 5000 ppm in volume of CO2 is the maximum allowed concentration within an 8 hour working period for humans. Generally levels are required to be below 600 ppm. Every astronaut generates around 1Kg CO2 / day which needs to be removed from the cabin air continuously. This system consists of staged Two-Phase Heat Exchangers (NTR: 49561), to selectively solidify water, trace contaminants and carbon dioxide. Deep space radiators provide the required cooling power, and solar heaters deliver the necessary heat to evaporate all the solidified species, during the system cycles. This is why, for missions beyond LEO, that no power is required. The energy requirements are passively collected from space. (Only a small amount of power is needed for control valves and electronics).Item Current Development Status of the Temperature Swing Adsorption Systems and Updated Trade Study Results(49th International Conference on Environmental Systems, 2019-07-07) Richardson, Tra-My Justine; Jan, DarrellA Carbon Dioxide Management System (CMS) trade study was conducted in 2018 to compare the Sabatier Assembly Compressor (SAC) used on the International Space Station (ISS) with the Air- Cooled Temperature Swing Compression System (AC-TSAC) and the Thermally-Coupled TSAC (TC-TSAC). Trade study results showed that the the TSAC systems trade favorably against the SAC. This paper outlines the current TSAC systems development status and provides the updated trade study analysis results.Item Development and Testing of a Two-Stage Air Drying System for Spacecraft Cabin CO2 Removal Systems(44th International Conference on Environmental Systems, 2014-07-13) Hogan, John; Jan, Darrell; Palmer, Gary H.; Richardson, Tra-My Justine; Linggi, Paul; Lu, Zhe; Kamiya, TakeshiThe use of molecular sieves such as zeolite for the removal of CO2 in spacecraft cabin atmospheres necessitates thorough water removal prior to processing. This is because water also binds readily with these sieves, and will lead to reduced CO2 loading capacity and water-contaminated CO2 streams for resource recovery. A two-stage air drying system has been under development at NASA Ames Research Center to address this need. The system consists of a membrane-based bulk dryer designed to passively remove up to 80% of the inlet water using the ultra-dry exhaust airstream from the CO2 removal system, and a regenerable, thermal-swing, structured-sorbent residual dryer that removes the remaining water to a nominal exit dew-point of -65oC. Individual unit testing of both of these units was conducted and indicates both are potential candidates for use in future missions. This paper provides that data from these tests.Item Development of the Liquid Amines Ground-Based Test System(50th International Conference on Environmental Systems, 7/12/2021) Chu, Lisa; Belancik, Grace; Samson, Jason; Jagtap, Pranav; Jan, Darrell; Yau, AllenRemoving carbon dioxide from breathable air is of vital safety and importance to future crewed missions. NASA Ames Research Center (ARC) is specifically investigating how to do this more efficiently using a liquid sorbent. One approach utilizes liquid amines as a liquid sorbent manipulated and contained via capillary flow. A test stand originally designed at NASA Johnson Space Center (JSC) is currently being used for testing which allows for air plug flow across a liquid sorbent contactor assembly. The current contactor configuration is set up with vertically oriented capillary flow wedges, but carbon dioxide (CO2) capture rates were found to be significantly lower than expected. Due to gravity, the liquid flow through the vertical wedges results in very low Diglycolamine Agent (DGA) retention time in the contactor assembly giving the DGA mixture insufficient time to absorb CO2. Furthermore, the current wedge orientation unfortunately does not allow for testing of different flow regimes because gravity-assist is currently the main limiting flow driver. Alternatively, it can be hypothesized that using a horizontal wedge configuration will allow for increased liquid retention time and testing of different flow regimes in the liquid sorbent contactor. Preliminary 3D modeling and air flow simulations are being created for a horizontally oriented wedge contactor. Since the original NASA JSC test stand allows for removal and replacement of the vertical contactor assembly, the new horizontal wedge configuration contactor is being designed to connect to the existing structure. With the new contactor design, it would then be possible to experimentally investigate the CO2 absorption relationship on liquid flow rate and other various liquid sorbent properties.Item Efficacy of FTIR Analysis in Determining CO2 Loading on Diglycolamine(48th International Conference on Environmental Systems, 2018-07-08) Huang, Roger; Silveria, Mark; Kong, Jessica; Belancik, Grace; Jan, DarrellIn support of advanced air revitalization technologies to enable human spaceflight beyond low earth orbit, performance studies have been conducted using a liquid amine, Diglycolamine (DGA) between teams at NASA’s Johnson Spaceflight Center (JSC) and Ames Research Center (ARC). Liquid amines have been used in regenerable earth-based systems to remove CO2 from industrial systems as well as for closed-environment air revitalization because they can be regenerated at lower temperatures than solid sorbent systems. As an additional advantage to solid sorbent-based systems, liquid sorbents can be cycled between an adsorbing contactor and degassing chamber, thereby reducing system complexity by operation in a continuous loop. In an effort to inform a regeneration system design for micro-gravity applications, ARC has performed a number of tests to characterize the degas mechanics of DGA. In order to accurately measure the amount of CO2 captured or released by the amine, methods such as gravimetric weighing and chemical desorption are reasonable, however the first iteration test setup for a scaled down degas system required analysis on small sample sizes. Fourier-transform infrared spectroscopy (FTIR) analysis was experimentally evaluated to analyze CO2 concentration because it can produce measurements with sample sizes on the order of 100’s of μL. Calibration against chemical desorption showed relatively good correlation and test data showed reasonable adherence to expected trends, however more extensive testing should be conducted to fully validate the usage of FTIR to determine CO2 loading on DGA.Item Evaluating Capabilities of the Carbon Dioxide Deposition System(2020 International Conference on Environmental Systems, 2020-07-31) Belancik, Grace; Schuh, Michael; Jan, Darrell; Jagtap, PranavHuman space exploration demands a highly reliable spacecraft cabin atmosphere revitalization system. One proposed concept deposits CO2 directly onto a cold surface, capitalizing on the condensation and deposition temperatures of air constituents. The cold surface can be generated using cryogenic coolers or thermal radiators. Since the CO2 Deposition System (CDep) system does not use an adsorbent material, CDep overcomes the limitations caused by performance degradation of the Carbon Dioxide Removal Assembly on ISS. This degradation has repeatedly increased maintenance costs over the years. CDep improves reliability and is an ideal candidate for long duration missions to deep space, moon, and beyond. The goal of this research is to characterize the trace contaminants and humidity capture on the subscale system previously designed for a single crew member. The single crew system consists of three Stirling coolers: one is used to precool the air and the other two operate in a cyclic manner for continuous CO2 removal. To simulate the environment of ISS, this system was evaluated by flowing representative trace contaminants and measuring their concentrations in the outlet gas flows. Additionally, controlled humidity was introduced into the system to determine the performance in maximum humidity conditions. CDep has successfully demonstrated its ability to both capture trace contaminants and withstand humidity loads simultaneously with nominal CO2 capture operation. Furthermore, this paper will also discuss design optimization of the cold surface to maximize the CO2 deposition for a full-scale (4-crew) system. The computational CO2 deposition study was conducted using a multi-physics code that directly modeled the CO2 deposition and conjugate heat transfer.Item Exploiting Capillary Sorbent Films for Air Revitalization aboard Spacecraft: Analysis of a Semi-Passive CO2 Scrubber(2020 International Conference on Environmental Systems, 2020-07-31) Weislogel, Mark; Torres, Logan; Jenson, Ryan; Graf, John; Hand, Lawerance; Belancik, Grace; Jan, Darrell; Levri, JulieLiquid sorbents have provided a primary means for robust carbon dioxide (CO2) control aboard submarines for decades. Unfortunately, such systems have not been adopted for use aboard spacecraft due to the fact that fine droplet sprays, thin falling films, and buoyancy-driven bubbly flows are not easily managed in the essentially gravity-free environments of orbiting spacecraft. Such applied engineering challenges have remained outstanding for the microgravity fluid physics community. As a work-around, in this research, a stable, silent capillary-driven ‘thin film’ is produced over a massively parallel network of open channels for both CO2 uptake and degas functions in a microgravity environment. Following several quantified assumptions, simple analytical models of species, heat, mass, and momentum transport are invoked providing clear design guides for a future engineering demonstration of the approach aboard the International Space Station. For critical sorbent properties such as CO2 capacity, effective diffusion rate, and concentration- and temperature-dependent viscosity, we provide the essential requirements of flow rate, size, shape, stability, power draw, and other aspects of the system. The results imply that a considerable reduction in system mass and volume is possible for the liquid sorbent approach for CO2 scrubbing when compared to the current state of the art.Item Improvements in Ionic Liquid Technology for Carbon Dioxide Removal Applications(2020 International Conference on Environmental Systems, 2020-07-31) Gurkan, Burcu; Jan, DarrellCarbon dioxide removal from cabin air continues to be of vital importance for future space missions. Current and proposed approaches have employed solid sorbents, hollow fiber membrane separators, and direct liquid sorbent contactors. Recent developments in ionic liquids have potential to improve performance in all three of these technologies. Efficient encapsulation of ionic liquids by polymeric shell can enable their use in a solid sorbent-like configuration without significant integration intervention to the current space technology. Poly(ionic liquid)-ionic liquid membranes have the potential to cross over the Robeson selectivity-permeability upper bound, and thereby outperform traditional membranes used in hollow fibers. Advances in ionic liquid chemistry enables performance improvements in liquid sorbent contactors owing to the tunable gravimetric CO2 capacity, reaction enthalpy and liquid viscosity. This paper will describe recent work in each of these areas.Item The Integrated Carbon Dioxide Removal, Compression, and Storage (CRCS) System(47th International Conference on Environmental Systems, 2017-07-16) Richardson, Tra-My Justine; Jan, Darrell; Hogan, John; Palmer, Gary; Huang, Roger; Belancik, Grace; Samson, Jason; Koss, BrianThe Carbon Dioxide Removal, Compression, and Storage (CRCS) system was designed to remove carbon dioxide (CO2(g)) from the spacecraft cabin atmosphere and compress and store the CO2(g) for further processing. Previous conference papers describe the hardware design and functional testing of the single and dual beds. This paper discusses the integrated system test results when dry CO2(g) latent air (2600ppm CO2(g)) enters the system at 30SCFM.Item Integrated CO2 Removal and Compression System Performance(46th International Conference on Environmental Systems, 2016-07-10) Richardson, Tra-My Justine; Jan, Darrell; Hogan, John; Huang, Roger; Samson, Jason; Palmer, Gary; Knox, JamesThe CO2 Removal and Compression System (CRCS) is designed to perform both the CO2 removal function of the four-bed molecular sieve (4BMS) system currently employed on the International Space Station (ISS), as well as additional integrated ability to purify and thermally compress CO2 to supply downstream CO2 recovery units. The CRCS approach will reduce cost and improve reliability for future long-duration missions. Previously, data has been presented for testing of a single unit of the 2-Stage Compressor. Data from those tests was used in the assembly a second unit and integration into a two unit system. Operation of the integrated two unit system will be described.Item Modeling Performance of the Full Scale CO2 Deposition System(50th International Conference on Environmental Systems, 7/12/2021) Belancik, Grace; Schuh, Michael; Jan, Darrell; Jagtap, PranavTo enable long-duration manned travel to the Moon and/or Mars, a highly reliable spacecraft cabin atmosphere revitalization system is required. One new carbon dioxide capture system currently in development is the CO2 Deposition System (CDep), which generates a cold surface to selectively deposit CO2 from cabin air. The cold surface may be generated via multiple methods and does not require use of sorbents. Therefore, CDep is a tunable assembly to minimize launch mass and power for any future spacecraft requirements. A full-scale (4-crew) ground test system is currently in development at Ames Research Center. The system utilizes multiple Stirling coolers and air-to-air heat exchangers to generate the cold surface and minimize power requirements. The system modeling is concurrently being developed in both STAR-CCM+ and Modelica to predict performance of the system. Utilizing the first principles STAR-CCM+ multi-physics code, the temperature, humidity, and CO2 concentration gradients across each of the heat exchangers and deposition surfaces were predicted, as well as the sublimation rates for downstream processing. Process modeling using Modelica was utilized to analyze the overall operation of the system to confirm the multi-physics results and examine the initial cool down and transitional phases alternating between deposition and sublimation. The results of the modeling work not only gave new insight into the CDep full-scale system, they informed design adjustments to improve the system prior to initial prototype completion.Item Numerical Characterization of Spacecraft Cabin Air Dehumidification System for CO2 Removal(50th International Conference on Environmental Systems, 7/12/2021) Jagtap, Pranav; Belancik, Grace; Jan, Darrell; Purdy, RyanAn extremely reliable, low maintenance cabin air revitalization system is required for manned deep space exploration missions. The CO2 deposition system (CDep) addresses this challenge. A cold surface is generated and maintained to selectively deposit CO2 from cabin air. To both reduce the power required to generate the cold surface and provide a purer CO2 downstream product, an ionic liquid dehumidification system was developed to supply continuous dry air to CDep. This system consists of hollow fiber membranes where ionic liquid flows through the lumen side and air flows through the shell side. The system can remove 96% of the humidity from cabin air with minimal power consumption. This paper presents the system and a numerical parametric study. The parametric study was conducted through a numeric model developed in Python with parameters such as flow rate of air and ionic liquid, inlet relative humidity, and porosity of the membranes. This study provided important insights to optimize the cabin air dehumidification system design and predict capability.Item Performance of Silica Gel in the Role of Residual Air Drying(44th International Conference on Environmental Systems, 2014-07-13) Jan, Darrell; Hogan, John; Koss, Brian; Palmer, Gary H.; Richardson, Tra-My Justine; Knox, James; Linggi, PaulRemoval of carbon dioxide (CO2) is a necessary step in air revitalization and is often accomplished with sorbent materials. Since moisture competes with CO2 in zeolite sorbent materials, it is necessary to remove the water first. This is typically accomplished in two stages: “bulk” removal and “residual” drying. Silica gel is used as the bulk drying material in the Carbon Dioxide Removal Assembly (CDRA) in operation on ISS. There has been some speculation that silica gel may also be capable of serving as the residual drying material. This paper describes test apparatus and procedures for determining the performance of silica gel in residual air drying.Item Performance of Silica Gel in the role of Residual Air Drying, Part II(46th International Conference on Environmental Systems, 2016-07-10) Richardson, Tra-My Justine; Jan, Darrell; Hogan, John; Huang, Roger; Palmer, Gary; Knox, JamesRemoval of carbon dioxide (CO2)is a necessary step in air revitalization and is often accomplished with sorbent materials. Since moisture competes with CO2 in sorbent materials, it is necessary to remove the water first. This is typically accomplished in two stages: “bulk” removal and “residual” drying. Silica gel is used as the bulk drying material in the Carbon Dioxide Removal Assembly (CDRA) in operation on ISS. There has been some speculation that silica gel may also be capable of serving as the residual drying material. This paper continues earlier efforts, on test apparatus and procedures, and results for determining the performance of silica gel in residual air drying.Item Power Optimization of Cryogenic CO2 Deposition Capture in Deep Space(2020 International Conference on Environmental Systems, 2020-07-31) Jagtap, Pranav; Belancik, Grace; Jan, Darrell; Hall, Scott; Chen, WeiboAn extremely reliable cabin air revitalization system is needed for human deep space exploration missions. Deep space offers an environmental temperature close to 4 Kelvin. This low environmental temperature enables heat rejection for systems that are thermally power-intensive, i.e. CO2 cold surface deposition (CDep). The CDep system relies on phase change temperatures of air components to deposit CO2 onto a cold surface. The cold surface can be generated utilizing cryocoolers, including Stirling and Reverse Brayton, or deep space environmental temperature. This paper presents a numerical study on a power optimization of cold surface generation via a cryocooler or thermal radiator. An example system for each type is presented. However, a hybrid system would not only reduce power required to remove CO2, but also increase redundancy and reliability of the CDep system.