Browsing by Author "Roychoudhury, Subir"
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Item CO2 Reduction Assembly Prototype using Microlith-based Sabatier Reactor for Ground Demonstration(44th International Conference on Environmental Systems, 2014-07-13) Junaedi, Christian; Hawley, Kyle; Walsh, Dennis; Roychoudhury, Subir; Abney, Morgan B.; Perry, Jay L.The utilization of CO2 to produce life support consumables, such as O2 and H2O, via the Sabatier reaction is an important aspect of NASA’s cabin Atmosphere Revitalization System (ARS) and In-Situ Resource Utilization (ISRU) architectures for both low-earth orbit and long-term manned space missions. Carbon dioxide can be reacted with H2, obtained from the electrolysis of water, via Sabatier reaction to produce methane and H2O. Methane can be stored and utilized as propellant while H2O can be either stored or electrolyzed to produce oxygen and regain the hydrogen atoms. Depending on the application, O2 can be used to replenish the atmosphere in human-crewed missions or as an oxidant for robotic and return missions. Precision Combustion, Inc. (PCI), with support from NASA, has previously developed an efficient and compact Sabatier reactor based on its Microlith® catalytic technology and demonstrated the capability to achieve high CO2 conversion and CH4 selectivity (i.e., ≥90% of the thermodynamic equilibrium values) at high space velocities and low operating temperatures. This was made possible through the use of high-heat-transfer and high-surface-area Microlith catalytic substrates. Using this Sabatier reactor, PCI designed, developed, and demonstrated a stand-alone CO2 Reduction Assembly (CRA) test system for ground demonstration and performance validation. The Sabatier reactor was integrated with the necessary balance-of-plant components and controls system, allowing an automated, single “push–button” start-up and shutdown. Additionally, the versatility of the test system prototype was demonstrated by operating it under H2-rich (H2/CO2 of >4), stoichiometric (ratio of 4), and CO2-rich conditions (ratio of <4) without affecting its performance and meeting the equilibrium-predicted water recovery rates. In this paper, the development of the CRA test system for ground demonstration will be discussed. Additionally, the performance results from testing the system at various operating conditions and the results from durability testing will be presented.Item Evaluation of CO2 Adsorber, Sabatier Reactor, and Solid Oxide Stack for Consumable, Propellant, and Power Production – Potential in ISRU Architecture(46th International Conference on Environmental Systems, 2016-07-10) Junaedi, Christian; Hawley, Kyle; Vilekar, Saurabh; Roychoudhury, SubirThe utilization of CO2 and regolith off-gases (e.g., methane and high hydrocarbons) to produce life support consumables, such as O2 and H2O, propellant fuels, and/or power is an important aspect of In-Situ Resource Utilization (ISRU) architecture for future, long duration planetary missions. One potential solution is to capture and use CO2 from the Martian atmosphere and/or hydrocarbons from regolith off-gas to generate the consumables, propellant fuels, and power. One approach is to chemically converting the collected carbon dioxide with H2, obtained from the electrolysis of water, via Sabatier reaction to produce methane and H2O. Methane can be stored and utilized as propellant while H2O can be either stored or recycled/electrolyzed to produce oxygen and regain the hydrogen atoms. Depending on the application, O2 can be used to replenish the atmosphere in human-crewed missions or as an oxidant for robotic and return missions. Alternatively, the generated and collected CH4 and O2 can be used as fuel in a solid oxide stack to produce power. Precision Combustion, Inc. (PCI), with support from NASA, has developed a regenerable adsorber technology for capturing CO2 from gaseous atmospheres (for both cabin atmosphere revitalization and ISRU applications) and a compact, efficient Sabatier reactor for converting CO2 to methane and water. Recently, we demonstrated a system concept for an innovative, high power density solid oxide stack for the utilization of methane and other hydrocarbons along with O2 to produce power. The resulting enhanced heat transfer and mass transfer design offers the potential for higher overall efficiency, simplifies the system, and enables further compactness and weight reduction of the system while improving the conditions for long system life. Here, the performance metrics and requirements from each technology will be presented. These include results from performance testing at various operating conditions and durability testing.Item Hydrogen Generation and Compression using Solid Oxide Membrane(2024 International Conference on Environmnetal Systems, 2024-07-21) Suzuki, Toshio; Dewa, Martinus; Junaedi, Christian; Roychoudhury, Subir; McLarty, DustinDevelopment of component and subsystem technologies for H2 production for planetary mission requirements is important to obtain sustainable, energy-efficient fuel production from planetary water and possible organic materials. Our development effort is intended to strongly emphasize significant overall efficiencies in component and system size, weight, and energy consumption and utilization for ISRU applications. Precision Combustion, Inc. (PCI) has been developing a new type of solid oxide membrane/cell that allows simultaneous H2 generation from planetary resources and compression at an intermediate-temperature based on a novel membrane architecture and materials, and processing techniques. Proof of concept testing of the new membrane/cell architecture indicated potential to be to be lightweight and presents several advantages over state of the art, including high gravimetric and volumetric power density, simplified solid oxide stack structure, rapid thermal cycle tolerance for fast start-up and shutdown, and more redox tolerant. Additionally, it is capable of operating in fuel cell mode for power generation with high fuel utilization, expected to realize high round trip efficiency. The goal is to generate high-purity H2 via electrolysis at a low energy consumption, and with simultaneous H2 compression to very high pressures. This avoids the need for a mechanical pump for compression, sweep gases, or gas separators essential for conventional solid oxide membranes. In this paper, we will present results from preliminary performance characterization of the lab-scale solid oxide membrane in both fuel cell and electrolysis mode. Performance evaluation under pressurized conditions will also be presented.Item Performance Evaluation of Regenerative Solid Oxide Stack(50th International Conference on Environmental Systems, 7/12/2021) Vilekar, Saurabh; Junaedi, Christian; Rehaag, Jessica; Qi, Chunming; Roychoudhury, SubirIn-Situ Resource Utilization (ISRU) allows consumption of local resources to produce life support consumables or propellants and is extremely critical for missions beyond low earth orbit where re-supply options are impractical. It is thus advantageous to develop unitized energy conversion device, capable of both energy storage and production within an integrated and process-intensified ISRU. Precision Combustion, Inc. (PCI), with support from NASA, continues to develop unitized, regenerative solid oxide stack system, capable of reforming lunar or Martian off-gases of various hydrocarbon lengths from methane to longer chain hydrocarbons for energy production (similar to battery discharging) as well as efficient H2O/CO2 electrolysis for energy storage (similar to battery charging). Challenges and risks regarding carbon deposition and thermal management associated with reversible hydrogen electrode for internal reforming have been addressed. The dual use regenerative fuel cell design is crucial to overcoming some of the known shortcomings of more traditional approaches. This approach has the potential to provide high power density, improve reliability, and enable quick cycling between power generation and electrolysis. In this paper, we will present results from performance evaluation of the unitized, regenerative solid oxide stack; including direct internal reforming and co-electrolysis of H2O and CO2. Results from durability and performance mapping at various operating conditions will be presented.Item Regenerative Solid Oxide Stack for Lunar and Mars Oxygen Production and Surface Energy Storage(48th International Conference on Environmental Systems, 2018-07-08) Vilekar, Saurabh; Junaedi, Christian; Gao, Zhan; Howard, Chris; Roychoudhury, SubirIn-Situ Resource Utilization (ISRU) is critical for expanding robotic and human extraterrestrial exploration beyond low earth orbit where re-supply options are nonexistent. Local resources need to be converted to useful products (e.g., life consumables and propellants) to reduce cost and risk and support human presence. Regenerative fuel cell systems offer increased storage capacity and can be used in future NASA missions to the moon, near-Earth asteroids, and Mars. Precision Combustion, Inc. (PCI), with support from NASA, is developing a regenerative solid oxide stack system approach that combines novel structural elements. Our approach allows direct internal reforming of regolith off-gases (e.g., methane and high hydrocarbons) within a solid oxide stack as well as efficient H2O/CO2 electrolysis for O2 production, overcoming shortcomings of traditional approaches. The resulting enhanced heat transfer design offers the potential for light-weight and simple stack design with high efficiency and durability. In this paper, we will present performance metrics including results from concept validation and performance testing at various operating conditions.Item Unitized Regenerative Solid Oxide Stack(49th International Conference on Environmental Systems, 2019-07-07) Vilekar, Saurabh; Junaedi, Christian; Allocco, Eric; Gao, Zhan; Roychoudhury, SubirEnergy storage and production in space via In-Situ Resource Utilization (ISRU) is critical for expanding robotic and human extraterrestrial exploration beyond low earth orbit where re-supply options are nonexistent. Traditional system configurations, in conjunction with photovoltaic solar arrays, comprise two separate systems: 1) fuel cell to convert fuel (e.g., H2) into electricity and 2) electrolyzer to produce O2 and fuel via electrolysis of in-situ resources. Development of Unitized Regenerative Solid Oxide (UR-SOC) Stack for providing both power and utilizing in-situ resources (e.g., H2O and CO2 for Mars mission) has the potential to provide high power density, improve reliability, and enable quick cycling between power generation and electrolysis within an integrated and process-intensified ISRU. Precision Combustion, Inc. (PCI), with support from NASA, has been developing a unitized regenerative solid oxide stack system. In this paper, we will present results from preliminary performance characterization of the UR-SOC and system concept design for diurnal operation. Capability for direct internal reforming of regolith off-gases (e.g., CH4 and higher hydrocarbons) within a solid oxide stack will also be presented.