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Project Title:  Development of Pressure Swing Adsorption Technology for Spaceflight Medical Oxygen Concentrators Reduce
Fiscal Year: FY 2013 
Division: Human Research 
Research Discipline/Element:
HRP ExMC:Exploration Medical Capabilities
Start Date: 09/01/2009  
End Date: 08/31/2013  
Task Last Updated: 01/08/2014 
Download report in PDF pdf
Principal Investigator/Affiliation:   Ritter, James A Ph.D. / University of South Carolina 
Address:  3C07 Swearingen Engineering Center 
Department of Chemical Engineering 
Columbia , SC 29208-4101 
Email: ritter@engr.sc.edu 
Phone: 803-777-3590  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of South Carolina 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Knox, James  NASA Marshall Space Flight Center 
Edwards, Paul  SeQual Technologies 
LeVan, Douglas  Vanderbilt University 
Project Information: Grant/Contract No. NCC 9-58-SMST02002 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2008 Crew Health NNJ08ZSA002N 
Grant/Contract No.: NCC 9-58-SMST02002 
Project Type: GROUND 
Flight Program:  
TechPort: Yes 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) ExMC:Exploration Medical Capabilities
Human Research Program Risks: (1) ExMC:Risk of Unacceptable Health and Mission Outcomes Due to Limitations of In-flight Medical Capabilities (IRP Rev E)
Human Research Program Gaps: (1) ExMC 4.04:We do not have the capability to deliver supplemental oxygen to crew members while minimizing local and cabin oxygen build-up during exploration missions (IRP Rev E)
Task Description: A source of medical oxygen will be needed at some point to keep an astronaut alive during a space mission. To meet this need, the ideal oxygen source would be a light, compact unit that uses minimal electricity, and can supply oxygen continuously for many days. No current technology meets these requirements. Traditional compressed-oxygen cylinders provide a limited amount of oxygen in a heavy, inconvenient package and are not suited for space missions. Oxygen concentrators, which extract oxygen from air using electricity, can eliminate the obvious problems with cylinder storage in space. These kinds of medical oxygen concentrators are already used in residential and military applications. However, existing systems are too big, use too much power, and are too heavy to be carried into space. For example, a unit that can produce oxygen continuously at 4 LPM (litres per minute), weigh less than 7 pounds, and use less than 100 Watts of electric power requires a two-fold reduction in weight and power consumption, compared with the most advanced oxygen concentrators now in production by SeQual. As proposed herein, this requirement may be met by combining new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology. SeQual and the team of researchers from the University of South Carolina (USC), Vanderbilt University (VU), and the Marshall Space Flight Center (MSFC) are uniquely positioned to achieve this next level of performance.

To determine whether the proposed technology advances are indeed possible, during the second year of this four year project, the four teams of researchers have been busy carrying out extensive mathematical modeling studies (USC), measuring equilibrium and kinetic parameters for the modeling effort (VU), performing carefully planned experiments with an Eclipse medical oxygen system modified for testing at the bench scale (SeQual), and gearing up for testing an Eclipse medical oxygen system under different environmental conditions (MSFC). Results from numerous experiments were used successfully to validate USC's Dynamic Adsorption Process Simulator (DAPS). In particular, DAPS was specially modified and calibrated against a SeQual PSA module under controlled conditions with a decoupled compressor, and the process performance was analyzed with respect to cycle speed, temperature, and high to low pressure ratio. Once validated, DAPS simulations focused on varying certain key process parameters to arrive at optimized PSA cycle designs. The learning from the design effort was implemented into a modified PSA module design operating a new PSA cycle, larger feed/exhaust ports, a backfill step, and larger recycle and purge ports. The new PSA module, associated compressor, and other components were fabricated and assembled on a breadboard. The breadboard was connected to instrumentation and tested. The new PSA design successfully delivered 4 lpm of product in about an 8 lb assembly with a compressor shaft power of 130 Watts. This was a significant outcome, especially since the new PSA design was based entirely on predictions from the DAPS. Overall, in the first two years of this four year project, this program is ahead of schedule and definitely on track for improving even further the efficiency of the PSA separation, with the project potentially culminating in a breadboard system that will supply 4 LPM of oxygen, weigh 7.2 lbs, require 106 Watts, and satisfy any new constraints imposed by NASA.

During year 3 the task outline presented in the original proposal was followed. In this way, carefully planned experiments carried out by the folks at SeQual were used to calibrate and further validate DAPS at USC. This was done in an attempt to further improve the performance of the PSA module and to understand the effects of potential process changes on its performance. SeQual also continued to develop their medical oxygen system based, in part, on the simulation results obtained from DAPS. These developments included breadboard testing, further optimization of bed and PSA cycle design, new prototype subcomponent detailed design and fabrication, new prototype preliminary tests, and improving on their process design and mechanical design capabilities. The team at Vanderbilt continued to measure and provide equilibrium and mass transfer properties for adsorbate-adsorbent pairs of interest to NASA adsorption technology. In addition, the entire medical oxygen system was evaluated based on new constraints imposed by NASA. During year 3, testing in a vacuum chamber with an Eclipse medical oxygen system was done at the MSFC to determine how it performs under International Space Station (ISS) environmental conditions.

There were 8 tasks associated with this project. These tasks are listed below. All were completed on schedule. In the year 1, Tasks 1, 2, and 6 were initiated. In the year 2, in addition, Tasks 3 and 4 were initiated, and Task 5 was initiated ahead of schedule. In year 3, Tasks 1-6 were all underway. In year 4, Tasks 1 to 8 were either completed, or underway and completed at the end of the period.

Research Impact/Earth Benefits: A major expectation of the research is the development of smaller medical oxygen concentrators, which will be of benefit not only for spaceflight but also for medical patients on Earth in need of oxygen enriched air.

Task Progress & Bibliography Information FY2013 
Task Progress: There were 8 tasks associated with this project. These tasks are listed below. All were completed on schedule. In the year 1, Tasks 1, 2, and 6 were initiated. In the year 2, in addition, Tasks 3 and 4 were initiated, and Task 5 was initiated ahead of schedule. In year 3, Tasks 1-6 were all underway. In year 4, Tasks 1 to 8 were either completed, or underway and completed at the end of the period. More detail about each task is provided below.

Task 1. Refine Model Parameters: Vanderbilt worked with USC to continually update the dynamic cyclic adsorption process simulator (DAPS) with the most up to date thermodynamic and kinetic parameters.

Task 2. Validate DAPS: USC worked with Chart to obtain system dimensions, operating conditions, and extensive experimental performance data of Chart's Eclipse system and then used it to calibrate and validate DAPS. Significant progress was made with respect to DAPS quantitatively predicting the performance of the Eclipse system.

Task 3. Optimize and Understand the Chart PSA Cycle: Using the refined and validated DAPS, USC, with input from Chart, carried out extensive parametric studies of Chart's PSA cycle to determine if it was possible to improve oxygen recovery, productivity, or both while maintaining the oxygen purity and without redesigning the PSA module. There were some key findings with DAPS that were recently verified experimentally by Chart.

Task 4. Examine Alternative PSA Cycles: Using the refined DAPS, USC, with input from Chart, explored new PSA cycle designs and cycle schedules to determine if it might be possible to improve the oxygen recovery, productivity, or both while maintaining the oxygen purity by redesigning the PSA module.

Task 5. Redesign and Build Improved PSA Module: Based on DAPS predictions, Chart designed a new PSA module that successfully delivered 4 lpm (litres per minute) of product in about an 8 lb assembly with a compressor shaft power of 130 Watts.

Task 6. Define Compressor Specifications and Build Feasibility Prototype for 4 LPM System: Chart developed a compressor suitable for a 3 LPM oxygen PSA system through a different funding source. Specifications and requirements were identified and a feasibility prototype was built built during this project to provide sufficient pressure and vacuum to supply a 4 LPM system.

Task 7. Assemble and Test Breadboard Systems: Chart assembled two breadboard demonstration systems that incorporated the new PSA module with the redesigned compressor. These breadboard systems are currently being tested by the MSFC and Glenn Research Center to determine new weight and performance targets and for down selection for flight development.

Task 8. Verify DAPS Predictions of New PSA Modules: Using the refined cyclic adsorption process simulator, USC carried out studies of redesigned systems and new prototypes to verify the simulation results, to determine optimum operating conditions, and to understand the performance limits of the new systems.

Bibliography Type: Description: (Last Updated: 08/28/2015) 

Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Giesy TJ, LeVan MD. "Mass transfer rates of oxygen, nitrogen, and argon in carbon molecular sieves determined by pressure-swing frequency response." Chemical Engineering Science. 2013 Mar 7;90:250-7. http://dx.doi.org/10.1016/j.ces.2012.12.029 , Mar-2013
Articles in Peer-reviewed Journals Giesy,TJ, Mitchell LA, LeVan MD. "Mass transfer of binary mixtures of oxygen and argon in a carbon molecular sieve." Industrial and Engineering Chemical Research. 2014 Jun 4;53(22):9221-7. (Originally reported as Publication Date (Web): December 20, 2013.) http://dx.doi.org/10.1021/ie4032742 , Jun-2014
Articles in Peer-reviewed Journals Mitchell LA, Tovar TM, LeVan MD. "High pressure excess isotherms for adsorption of oxygen and argon in a carbon molecular sieve." Carbon. 2014 Aug;74:120-6. http://dx.doi.org/10.1016/j.carbon.2014.03.012 , Aug-2014
Awards Ritter JA. "Named Fellow of the American Institute of Chemical Engineers, July 2013." Jul-2013
Awards LeVan MD. "Honorary Session for Prof. M. Douglas LeVan, AIChE Annual Meeting, San Francisco, California, November 2013." Nov-2013
Awards LeVan MD. "Recipient of Vanderbilt Institute for Nanoscale Science and Engineering (VINSE) High Impact Paper Award, April 2013." Apr-2013
NASA Technical Documents Gilkey KM, Olson SL. "Evaluation of the oxygen concentrator prototypes: Pressure swing adsorption prototype and electrochemical prototype." Cleveland, OH: NASA Glenn Research Center, 2015 Mar. 42 p. Report No.: NASA/TM-2015-218709. http://ntrs.nasa.gov/search.jsp?R=20150011038&hterms=20150011038&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchallany%26Ntt%3D20150011038 , Mar-2015
Project Title:  Development of Pressure Swing Adsorption Technology for Spaceflight Medical Oxygen Concentrators Reduce
Fiscal Year: FY 2012 
Division: Human Research 
Research Discipline/Element:
HRP ExMC:Exploration Medical Capabilities
Start Date: 09/01/2009  
End Date: 08/31/2013  
Task Last Updated: 10/19/2012 
Download report in PDF pdf
Principal Investigator/Affiliation:   Ritter, James A Ph.D. / University of South Carolina 
Address:  3C07 Swearingen Engineering Center 
Department of Chemical Engineering 
Columbia , SC 29208-4101 
Email: ritter@engr.sc.edu 
Phone: 803-777-3590  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of South Carolina 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Knox, James  NASA Marshall Space Flight Center 
Edwards, Paul  SeQual Technologies 
LeVan, Douglas  Vanderbilt University 
Project Information: Grant/Contract No. NCC 9-58-SMST02002 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2008 Crew Health NNJ08ZSA002N 
Grant/Contract No.: NCC 9-58-SMST02002 
Project Type: GROUND 
Flight Program:  
TechPort: Yes 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) ExMC:Exploration Medical Capabilities
Human Research Program Risks: (1) ExMC:Risk of Unacceptable Health and Mission Outcomes Due to Limitations of In-flight Medical Capabilities (IRP Rev E)
Human Research Program Gaps: (1) ExMC 4.04:We do not have the capability to deliver supplemental oxygen to crew members while minimizing local and cabin oxygen build-up during exploration missions (IRP Rev E)
Task Description: A source of medical oxygen will be needed at some point to keep an astronaut alive during a space mission. To meet this need, the ideal oxygen source would be a light, compact unit that uses minimal electricity, and can supply oxygen continuously for many days. No current technology meets these requirements. Traditional compressed-oxygen cylinders provide a limited amount of oxygen in a heavy, inconvenient package and are not suited for space missions. Oxygen concentrators, which extract oxygen from air using electricity, can eliminate the obvious problems with cylinder storage in space. These kinds of medical oxygen concentrators are already used in residential and military applications. However, existing systems are too big, use too much power, and are too heavy to be carried into space. For example, a unit that can produce oxygen continuously at 4 LPM, weigh less than 7 pounds and use less than 100 Watts of electric power requires a two-fold reduction in weight and power consumption, compared with the most advanced oxygen concentrators now in production by SeQual. As proposed herein, this requirement may be met by combining new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology. SeQual and the team of researchers from the University of South Carolina, Vanderbilt University and the Marshall Space Flight Center are uniquely positioned to achieve this next level of performance.

To determine whether the proposed technology advances are indeed possible, during the second year of this four year project, the four teams of researchers have been busy carrying out extensive mathematical modeling studies (USC), measuring equilibrium and kinetic parameters for the modeling effort (VU), performing carefully planned experiments with an Eclipse medical oxygen system modified for testing at the bench scale (SeQual), and gearing up for testing an Eclipse medical oxygen system under different environmental conditions (MSFC). Results from numerous experiments were used successfully to validate USC's Dynamic Adsorption Process Simulator (DAPS). In particular, DAPS was specially modified and calibrated against a SeQual PSA module under controlled conditions with a decoupled compressor, and the process performance was analyzed with respect to cycle speed, temperature and high to low pressure ratio. Once validated, DAPS simulations focused on varying certain key process parameters to arrive at optimized PSA cycle designs. The learning from the design effort was implemented into a modified PSA module design operating a new PSA cycle, larger feed/exhaust ports, a backfill step, and larger recycle and purge ports. The new PSA module, associated compressor and other components were fabricated and assembled on a breadboard. The breadboard was connected to instrumentation and tested. The new PSA design successfully delivered 4 lpm of product in about an 8 lb assembly with a compressor shaft power of 130 Watts. This was a significant outcome, especially since the new PSA design was based entirely on predictions from the DAPS. Overall, in the first two years of this four year project, this program is ahead of schedule and definitely on track for improving even further the efficiency of the PSA separation, with the project potentially culminating in a breadboard system that will supply 4 LPM of oxygen, weigh 7.2 lbs, require 106 Watts, and satisfy any new constraints imposed by NASA.

During year 3 the task outline presented in the original proposal was followed. In this way, carefully planned experiments carried out by the folks at SeQual were used to calibrate and further validate DAPS at USC. This was done in an attempt to further improve the performance of the PSA module and to understand the effects of potential process changes on its performance. These results with DAPS will be obtained in year 4. SeQual also continued to develop their medical oxygen system based, in part, on the simulation results obtained from DAPS. These developments included breadboard testing, further optimization of bed and PSA cycle design, new prototype subcomponent detailed design and fabrication, new prototype preliminary tests, and improving on their process design and mechanical design capabilities. The team at Vanderbilt is continuing to measure and provide equilibrium and mass transfer properties for adsorbate-adsorbent pairs of interest to NASA adsorption technology. In addition, the entire medical oxygen system is being evaluated based on new constraints imposed by NASA. During year 3, testing in a vacuum chamber with an Eclipse medical oxygen system has also been underway at the MSFC to determine how it performs under International Space Station (ISS) environmental conditions.

Year 4 will continue to follow the task outline presented in the original proposal. In this way, based on the best predictions from DAPS, a breadboard system will be built at SeQual and tested there, by the folks at the MSFC and by a team at Glenn. The intent of the team at Glen is to down-select from the medical oxygen systems under their consideration.

Research Impact/Earth Benefits: A major expectation of the research is the development of smaller medical oxygen concentrators, which will be of benefit not only for space flight but also for medical patients on Earth in need of oxygen enriched air.

Task Progress & Bibliography Information FY2012 
Task Progress: There are 8 tasks associated with this project. These tasks are listed below. All are on or ahead of schedule. In the year 1, Tasks 1, 2, and 6 were initiated. In the year 2, in addition, Tasks 3 and 4 were initiated, and Task 5 was initiated ahead of schedule. In year 3 Tasks 1-6 were all underway. Progress has been made for each of these tasks. More detail is provided below.

Task 1. Refine Model Parameters: Vanderbilt has been working with USC to update the dynamic cyclic adsorption process simulator (DAPS) with the most up to date thermodynamic and kinetic parameters.

Task 2. Validate DAPS: USC has been working with SeQual to obtain system dimensions, operating conditions and extensive experimental performance data of SeQual's Eclipse system and then using it to calibrate and validate DAPS. Significant progress has been made with respect to DAPS quantitatively predicting the performance of the Eclipse system.

Task 3. Optimize and Understand the SeQual PSA Cycle: Using the refined and validated DAPS, USC, with input from SeQual, have been carrying out extensive parametric studies of SeQual's PSA cycle to determine if it is possible to improve oxygen recovery, productivity or both while maintaining the oxygen purity and without redesigning the PSA module. There have been some key findings with DAPS. Some of these findings were recently verified experimentally by SeQual.

Task 4. Examine Alternative PSA Cycles: Using the refined DAPS, USC, with input from SeQual, from SeQual, have been exploring new PSA cycle designs and cycle schedules to determine if it might be possible to improve the oxygen recovery, productivity or both while maintaining the oxygen purity by redesigning the PSA module.

Task 5. Redesign and Build Improved PSA Module: Based on DAPS predictions, SeQual designed a new PSA module that successfully delivered 4 lpm of product in about an 8 lb assembly with a compressor shaft power of 130 Watts.

Task 6. Define Compressor Specifications and Build Feasibility Prototype for 4 LPM System: SeQual has an operating compressor suitable for a 3 LPM oxygen PSA system through a different funding source. Specifications and requirements have been identified and a feasibility prototype is being built to provide sufficient pressure and vacuum to supply the 4 LPM system.

Task 7. Assemble and Test Breadboard Systems: SeQual will assemble at least two breadboard demonstration systems that incorporate the new PSA module with the existing reciprocating or possibly a redesigned compressor. These breadboard systems will be tested by SeQual, the MSFC and Glen and used to determine new weight and performance targets.

Task 8. Verify DAPS Predictions of New PSA Modules: Using the refined cyclic adsorption process simulator, USC will carry out studies of redesigned systems or new prototypes to verify the simulation results, to determine optimum operating conditions, and to understand the performance limits of the new systems.

Bibliography Type: Description: (Last Updated: 08/28/2015) 

Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Bhadra SJ, Ebner AD, Ritter JA. "On the use of the dual process Langmuir model for predicting unary and binary isosteric heats of adsorption." Langmuir. 2012 May 1;28(17):6935-41. Epub 2012 Apr 18. http://dx.doi.org/10.1021/la301004e ; PubMed PMID: 22480343 , May-2012
Articles in Peer-reviewed Journals Giesy TJ, Wang Y, LeVan MD. "Measurement of mass transfer rates in adsorbents: new combined-technique frequency response apparatus and application to CO2 in 13x zeolite." Industrial & Engineering Chemistry Research. 2012,Sep 5;51(35):11509–17. http://dx.doi.org/10.1021/ie3014204 , Sep-2012
Awards Ritter JA. "Named a Fellow of the American Chemical Society, July 2012." Jul-2012
Awards Ritter JA. "Recipient of the 2012 USC Educational Foundation Research Award for Science, Mathematics, and Engineering, May 2012." May-2012
Project Title:  Development of Pressure Swing Adsorption Technology for Spaceflight Medical Oxygen Concentrators Reduce
Fiscal Year: FY 2011 
Division: Human Research 
Research Discipline/Element:
HRP ExMC:Exploration Medical Capabilities
Start Date: 09/01/2009  
End Date: 08/31/2013  
Task Last Updated: 10/12/2011 
Download report in PDF pdf
Principal Investigator/Affiliation:   Ritter, James A Ph.D. / University of South Carolina 
Address:  3C07 Swearingen Engineering Center 
Department of Chemical Engineering 
Columbia , SC 29208-4101 
Email: ritter@engr.sc.edu 
Phone: 803-777-3590  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of South Carolina 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Knox, James  NASA Marshall Space Flight Center 
Edwards, Paul  SeQual Technologies 
LeVan, Douglas  Vanderbilt University 
Project Information: Grant/Contract No. NCC 9-58-SMST02002 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2008 Crew Health NNJ08ZSA002N 
Grant/Contract No.: NCC 9-58-SMST02002 
Project Type: GROUND 
Flight Program:  
TechPort: Yes 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) ExMC:Exploration Medical Capabilities
Human Research Program Risks: (1) ExMC:Risk of Unacceptable Health and Mission Outcomes Due to Limitations of In-flight Medical Capabilities (IRP Rev E)
Human Research Program Gaps: (1) ExMC 4.04:We do not have the capability to deliver supplemental oxygen to crew members while minimizing local and cabin oxygen build-up during exploration missions (IRP Rev E)
Task Description: A source of medical oxygen will be needed at some point to keep an astronaut alive during a space mission. To meet this need, the ideal oxygen source would be a light, compact unit that uses minimal electricity, and can supply oxygen continuously for many days. No current technology meets these requirements. Traditional compressed-oxygen cylinders provide a limited amount of oxygen in a heavy, inconvenient package and are not suited for space missions. Oxygen concentrators, which extract oxygen from air using electricity, can eliminate the obvious problems with cylinder storage in space. These kinds of medical oxygen concentrators are already used in residential and military applications. However, existing systems are too big, use too much power, and are too heavy to be carried into space. For example, a unit that can produce oxygen continuously at 4 LPM, weigh less than 7 pounds and use less than 100 Watts of electric power requires a two-fold reduction in weight and power consumption, compared with the most advanced oxygen concentrators now in production by SeQual. As proposed herein, this requirement may be met by combining new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology. SeQual and the team of researchers from the University of South Carolina (USC), Vanderbilt University (VU), and the Marshall Space Flight Center (MSFC) are uniquely positioned to achieve this next level of performance.

To determine whether the proposed technology advances are indeed possible, during the second year of this four year project, the four teams of researchers have been busy carrying out extensive mathematical modeling studies (USC), measuring equilibrium and kinetic parameters for the modeling effort (VU), performing carefully planned experiments with an Eclipse medical oxygen system modified for testing at the bench scale (SeQual), and gearing up for testing an Eclipse medical oxygen system under different environmental conditions (MSFC). Results from numerous experiments were used successfully to validate USC's Dynamic Adsorption Process Simulator (DAPS). In particular, DAPS was specially modified and calibrated against a SeQual PSA module under controlled conditions with a decoupled compressor, and the process performance was analyzed with respect to cycle speed, temperature and high to low pressure ratio. Once validated, DAPS simulations focused on varying certain key process parameters to arrive at optimized PSA cycle designs. The learning from the design effort was implemented into a modified PSA module design operating a new PSA cycle, larger feed/exhaust ports, a backfill step, and larger recycle and purge ports. The new PSA module, associated compressor and other components were fabricated and assembled on a breadboard. The breadboard was connected to instrumentation and tested. The new PSA design successfully delivered 4 lpm of product in about an 8 lb assembly with a compressor shaft power of 130 Watts. This was a significant outcome, especially since the new PSA design was based entirely on predictions from the DAPS. Overall, in the first two years of this four year project, this program is ahead of schedule and definitely on track for improving even further the efficiency of the PSA separation, with the project potentially culminating in a breadboard system that will supply 4 LPM of oxygen, weigh 7.2 lbs, require 106 Watts, and satisfy any new constraints imposed by NASA.

Year 3 will continue to follow the task outline presented in the original proposal. In this way, continually updated versions of DAPS will be used, along with carefully planned experiments, to further improve the performance of the PSA module. In addition, the compressor and other components will be evaluated based on new constraints imposed by NASA. Testing in a vacuum chamber with an Eclipse medical oxygen system will also be initiated to determine how it performs under International Space Station (ISS) environmental conditions.

Research Impact/Earth Benefits: A major expectation of the research is the development of smaller medical oxygen concentrators, which will be of benefit not only for space flight but also for medical patients on Earth in need of oxygen enriched air.

Task Progress & Bibliography Information FY2011 
Task Progress: There are 8 tasks associated with this project: 1. Refine model parameters; 2. Validate dynamic adsorption process simulator (DAPS); 3. Optimize and understand the SeQual PSA cycle; 4. Examine alternative PSA cycles; 5. Redesign and build improved PSA module for 4 LPM system; 6. Define compressor specifications and build feasibility prototype for 4 LPM system; 7. Assemble and test breadboard systems; and 8. Verify DAPS predictions of new PSA modules. The project is on or ahead of schedule.

In the first year, Tasks 1, 2, and 6 were initiated. In the second year, in addition, Tasks 3 and 4 were initiated, and Task 5 was initiated ahead of schedule. Progress has been made for each of these tasks. More detail is provided below.

Task 1. Refine Model Parameters VU and USC): LeVan and his team have been working with Ritter and his team to update the dynamic cyclic adsorption process simulator (DAPS) with the most up to date thermodynamic and kinetic parameters. This task is on schedule.

Task 2. Validate DAPS (USC and SeQual): Ritter and his team have been working with SeQual to obtain system dimensions, operating conditions and extensive experimental performance data of SeQual's Eclipse system and then using it to calibrate and validate DAPS. Significant progress has been made with respect to DAPS quantitatively predicting the performance of the Eclipse system. This task is on schedule.

Task 3. Optimize and Understand the SeQual PSA Cycle (USC and SeQual): Using the refined and validated DAPS, Ritter and his team, with input from SeQual, have been carrying out extensive parametric studies of SeQual's PSA cycle to determine if it is possible to improve oxygen recovery, productivity or both while maintaining the oxygen purity and without redesigning the PSA module. There have been some key findings with DAPS. Some of these findings were recently verified experimentally by SeQual. This task is ahead of schedule.

Task 4. Examine Alternative PSA Cycles (USC): Using the refined DAPS, Ritter and his team, with input from SeQual, are just beginning to explore new PSA cycle designs and cycle schedules to determine if it might be possible to improve the oxygen recovery, productivity or both while maintaining the oxygen purity by redesigning the PSA module. This task is ahead of schedule.

Task 5. Redesign and Build Improved PSA Module (SeQual): Based on DAPS predictions, SeQual designed a new PSA module that successfully delivered 4 lpm of product in about an 8 lb assembly with a compressor shaft power of 130 Watts. This task is ahead of schedule.

Task 6. Define Compressor Specifications and Build Feasibility Prototype for 4 LPM System (SeQual): SeQual has an operating compressor suitable for a 3 LPM oxygen PSA system through a different funding source. Specifications and requirements have been identified and a feasibility prototype is being built to provide sufficient pressure and vacuum to supply the 4 LPM system. This task is on schedule.

Bibliography Type: Description: (Last Updated: 08/28/2015) 

Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Ebner AD, Gray ML, Chisholm NG, Black QT, Mumford DD, Nicholson MA, Ritter JA. "Suitability of a solid amine sorbent for CO2 capture by pressure swing adsorption" Industrial & Engineering Chemistry Research 2011 May 4; 50(9):5634-41. http://dx.doi.org/10.1021/ie2000709 , May-2011
Articles in Peer-reviewed Journals Mehrotra A, Ebner AD, Ritter JA. "Simplified graphical approach for complex PSA cycle scheduling." Adsorption. 2011 Apr;17(2):337-45. http://dx.doi.org/10.1007/s10450-011-9326-6 , Apr-2011
Articles in Peer-reviewed Journals Ritter JA, Bhadra SJ, Ebner AD. "On the use of the dual-process Langmuir model for correlating unary equilibria and predicting mixed-gas adsorption equilibria." Langmuir. 2011 Apr 19;27(8):4700-12. Epub 2011 Mar 17. PubMed PMID: 21413784 ; http://dx.doi.org/10.1021/la104965w , Apr-2011
Articles in Peer-reviewed Journals Wang Y, Helvensteijn B, Nizamidin N, Erion AM, Steiner LA, Mulloth LM, Luna B, Levan MD. "High pressure excess isotherms for adsorption of oxygen and nitrogen in zeolites." Langmuir. 2011 Sep 6;27(17):10648-56. Epub 2011 Jul 28. http://dx.doi.org/10.1021/la201690x ; PubMed PMID: 21744870 , Sep-2011
Project Title:  Development of Pressure Swing Adsorption Technology for Spaceflight Medical Oxygen Concentrators Reduce
Fiscal Year: FY 2010 
Division: Human Research 
Research Discipline/Element:
HRP ExMC:Exploration Medical Capabilities
Start Date: 09/01/2009  
End Date: 08/31/2013  
Task Last Updated: 09/14/2010 
Download report in PDF pdf
Principal Investigator/Affiliation:   Ritter, James A Ph.D. / University of South Carolina 
Address:  3C07 Swearingen Engineering Center 
Department of Chemical Engineering 
Columbia , SC 29208-4101 
Email: ritter@engr.sc.edu 
Phone: 803-777-3590  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of South Carolina 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Knox, James  NASA Marshall Space Flight Center 
Edwards, Paul  SeQual Technologies 
LeVan, Douglas  Vanderbilt University 
Project Information: Grant/Contract No. NCC 9-58-SMST02002 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2008 Crew Health NNJ08ZSA002N 
Grant/Contract No.: NCC 9-58-SMST02002 
Project Type: GROUND 
Flight Program:  
TechPort: Yes 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Human Research Program Elements: (1) ExMC:Exploration Medical Capabilities
Human Research Program Risks: (1) ExMC:Risk of Unacceptable Health and Mission Outcomes Due to Limitations of In-flight Medical Capabilities (IRP Rev E)
Human Research Program Gaps: (1) ExMC 4.04:We do not have the capability to deliver supplemental oxygen to crew members while minimizing local and cabin oxygen build-up during exploration missions (IRP Rev E)
Task Description: A source of medical oxygen will be needed at some point to keep an astronaut alive during a space mission. To meet this need, the ideal oxygen source would be a light, compact unit that uses minimal electricity, and can supply oxygen continuously for many days. No current technology meets these requirements. Traditional compressed-oxygen cylinders provide a limited amount of oxygen in a heavy, inconvenient package and are not suited for space missions. Oxygen concentrators, which extract oxygen from air using electricity, can eliminate the obvious problems with cylinder storage in space. These kinds of medical oxygen concentrators are already used in residential and military applications. However, existing systems are too big, use too much power, and are too heavy to be carried into space. For example, a unit that can produce oxygen continuously at 4 LPM, weigh less than 7 pounds and use less than 100 Watts of electric power requires a two-fold reduction in weight and power consumption, compared with the most advanced oxygen concentrators now in production by SeQual. As proposed herein, this requirement may be met by combining new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology. SeQual and the team of researchers from the University of South Carolina, Vanderbilt University and the Marshall Space Flight Center are uniquely positioned to achieve this next level of performance.

To determine whether the proposed technology advances are indeed possible, during the first year of this four year project, the four teams of researchers have been carrying out an extensive mathematical modeling study, combined with carefully planned experiments, based on SeQual's state-of-the-art Eclipse medical oxygen system. Results from the experiments were used successfully to validate the rigorous mathematical model. Subsequent results from the modeling effort were very enlightening and are currently being evaluated to determine whether they warrant carrying out a new breadboard system design. In the mean time, the group at Vanderbilt has been busy setting up equilibrium and mass transfer measurement apparatuses that will be key to ensuring the accuracy of the mathematical modeling effort; and the group at the MSFC has been setting up a test facility for evaluating the Eclipse and other breadboard system designs in different low pressure environments. Thus, during the first year of this four year project, this program is definitely on track for improving the efficiency of the PSA separation, with the project culminating in a breadboard system that will supply 4 LPM of oxygen, weigh 7.2 pounds and require 106 watts of electric power.

Research Impact/Earth Benefits: A major expectation of the research is the development of smaller medical oxygen concentrators, which will be of benefit not only for space flight but also for medical patients on Earth in need of oxygen-enriched air.

Task Progress & Bibliography Information FY2010 
Task Progress: There are 8 tasks associated with this project. These are:

1. Refine model parameters; 2. Validate dynamic adsorption process simulator (DAPS) ; 3. Optimize and understand the SeQual PSA cycle; 4. Examine alternative PSA cycles; 5. Redesign and build improved PSA module for 4 LPM system; 6. Define compressor specifications and build feasibility prototype for 4 LPM system; 7. Assemble and test breadboard systems; and 8. Verify DAPS predictions of new PSA modules.

In the first year, only Tasks 1, 2 and 6 were to be initiated. Progress has been made for each of these three tasks, as well as with Task 3 and Task 4 is just being initiated. More detail about each of these tasks is provided below.

Task 1. Refine Model Parameters VU and USC): Professor LeVan and his team have been working with Professor Ritter and his team to update the dynamic cyclic adsorption process simulator (DAPS) with the most up to date thermodynamic and kinetic parameters. This task is on schedule.

Task 2. Validate Dynamic Adsorption Process Simulator (USC and SeQual): Professor Ritter and his team have been working with SeQual to obtain system dimensions, operating conditions and extensive experimental performance data of SeQual's Eclipse system and then using it to calibrate and validate the dynamic adsorption process simulator (DAPS). This task is on schedule and significant progress has been made with respect to DAPS quantitatively predicting the performance of the Eclipse system. This task is on schedule.

Task 3. Optimize and Understand the SeQual PSA Cycle (USC and SeQual): Using the refined and validated DAPS, Professor Ritter and his team, with input from SeQual, have been carrying out extensive parametric studies of SeQual's PSA cycle to determine if it is possible to improve oxygen recovery, productivity or both while maintaining the oxygen purity and without redesigning the PSA module. There have been some key findings with DAPS that will be tested experimentally by both SeQual and the MSFC in subsequent years of this project. This task is ahead of schedule.

Task 4. Examine Alternative PSA Cycles (USC): Using the refined DAPS, Professor Ritter and his team, with input from SeQual, are just beginning to explore new cycle designs and cycle schedules to determine if it might be possible to improve the oxygen recovery, productivity or both while maintaining the oxygen purity by redesigning the PSA module. This task is ahead of schedule.

Task 6. Define Compressor Specifications and Build Feasibility Prototype for 4 LPM System (SeQual): SeQual has an operating compressor suitable for a 3 LPM oxygen PSA system through a different funding source. Specifications and requirements have been identified and a feasibility prototype is being built to provide sufficient pressure and vacuum to supply the 4 LPM system. This task is on schedule.

Bibliography Type: Description: (Last Updated: 08/28/2015) 

Show Cumulative Bibliography Listing
 
 None in FY 2010
Project Title:  Development of Pressure Swing Adsorption Technology for Spaceflight Medical Oxygen Concentrators Reduce
Fiscal Year: FY 2009 
Division: Human Research 
Research Discipline/Element:
HRP ExMC:Exploration Medical Capabilities
Start Date: 09/01/2009  
End Date: 08/31/2013  
Task Last Updated: 07/17/2009 
Download report in PDF pdf
Principal Investigator/Affiliation:   Ritter, James A Ph.D. / University of South Carolina 
Address:  3C07 Swearingen Engineering Center 
Department of Chemical Engineering 
Columbia , SC 29208-4101 
Email: ritter@engr.sc.edu 
Phone: 803-777-3590  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of South Carolina 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
LeVan, M Douglas Vanderbilt University 
Edwards, Paul  SeQual Technologies 
Knox, James  NASA Marshall Space Flight Center 
Project Information: Grant/Contract No. NCC 9-58-SMST02002 
Responsible Center: NSBRI 
Grant Monitor:  
Center Contact:   
Solicitation / Funding Source: 2008 Crew Health NNJ08ZSA002N 
Grant/Contract No.: NCC 9-58-SMST02002 
Project Type: GROUND 
Flight Program:  
TechPort: Yes 
No. of Post Docs:  
No. of PhD Candidates:  
No. of Master's Candidates:  
No. of Bachelor's Candidates:  
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Human Research Program Elements: (1) ExMC:Exploration Medical Capabilities
Human Research Program Risks: (1) ExMC:Risk of Unacceptable Health and Mission Outcomes Due to Limitations of In-flight Medical Capabilities (IRP Rev E)
Human Research Program Gaps: (1) ExMC 4.04:We do not have the capability to deliver supplemental oxygen to crew members while minimizing local and cabin oxygen build-up during exploration missions (IRP Rev E)
Task Description: A source of medical oxygen will be needed at some point to keep an astronaut alive during a space mission. To meet this need, the ideal oxygen source would be a light, compact unit that uses minimal electricity and can supply oxygen continuously for many days. No current technology meets these requirements.

Traditional compressed-oxygen cylinders provide a limited amount of oxygen in a heavy, inconvenient package and are not suited for space missions. Oxygen concentrators, which extract oxygen from air using electricity, can eliminate the obvious problems with cylinder storage in space. These kinds of medical oxygen concentrators are already used in residential and military applications. However, existing systems are too big, use too much power, and are too heavy to be carried into space. For example, a unit that can produce oxygen continuously at 4 liters per minute (LPM), weigh less than 7 pounds and use less than 100 watts of electric power requires a two-fold reduction in weight and power consumption, compared with the most advanced oxygen concentrators now in production by SeQual Technologies.

However, as proposed in this project, this requirement may be met by combining new air compressor designs with advances in Pressure Swing Adsorption (PSA) technology. SeQual and researchers from the University of South Carolina, Vanderbilt University and the Marshall Space Flight Center are uniquely positioned to achieve this next level of performance. To determine whether this is possible, the research team will carry out an extensive mathematical modeling study of the physical system using computer simulation, coupled with breadboard system design and testing. It is anticipated that this project will identify approaches to improve the efficiency of the PSA separation and thus culminate in a breadboard system that will supply 4 LPM of oxygen, weigh 7.2 pounds and require 106 watts of electric power.

Research Impact/Earth Benefits: 0

Task Progress & Bibliography Information FY2009 
Task Progress: New project for FY2009.

Bibliography Type: Description: (Last Updated: 08/28/2015) 

Show Cumulative Bibliography Listing
 
 None in FY 2009