Browsing by Author "Childers, Amanda"
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Item CDRILS 4-crew-scale CO2 Removal and Reduction Flight Unit Design(2024 International Conference on Environmnetal Systems, 2024-07-21) Henson, Phoebe; Pipitone, Meghan; ; Clark, Zachery; Butterwick, Sam; Pope, Eric; Childers, Amanda; Yates, Stephen F.The Carbon Dioxide Removal by Ionic Liquid System (CDRILS) utilizes a continuously recirculated ionic liquid sorbent and hollow fiber membrane contactors for carbon dioxide removal from air. The CDRILS flight demonstration unit design has been refined with selected flight components, demonstrated flight-scale contactors, custom volume-saving manifolds and secondary containment components, and an integrated Sabatier. Integrated CO2 reduction to methane via a Sabatier saves size, weight, volume, and power compared to CO2 storage and conversion in separate systems. It also allows waste heat from the Sabatier reaction to be repurposed for ionic liquid heating via a thermal link for power savings to CDRILS. Preliminary CDRILS interface and safety requirements were derived from the NASA ISS program documentation and have been considered in the design concepts. The refined design continues to fit within half of an ISS Basic Express Rack (BER). Several important supporting components unique to CDRILS or with stringent power and durability requirements have been evaluated off-the-shelf or through custom development, including the vacuum pump, blower, dehumidifier, water separator, and Sabatier reactor. Concepts for CDRILS integration with methane pyrolysis and other ECLSS subsystems are outlined.Item Chemical Vapor Deposition Methane Pyrolysis Enables Closed-loop Oxygen Recovery: Path to Flight(51st International Conference on Environmental Systems, 7/10/2022) Childers, Amanda; Yates, Stephen; Parsons, Abigail; Spencer, Jeff; Smoke, Jason; Mehr, MehradDeep-space long-duration human exploration missions to Mars will require advanced oxygen recovery technologies. Honeywell Aerospace is developing a methane pyrolysis technology in partnership with NASA that would recover hydrogen from the methane generated by the existing Sabatier unit during recovered carbon dioxide reduction. Complete pyrolysis of this methane to carbon increases the overall system oxygen recovery to almost 100%, while leveraging proven Sabatier technology. Due to the high-temperature, low-pressure pyrolysis reaction, flight-ready reactor hardware must limit heat loss, employ robust materials of construction, and optimize performance. Honeywell is designing a flight-like methane pyrolysis reactor that will utilize advanced materials of construction and state-of-the-art thermal optimization. Computational fluid dynamics (CFD) simulations of the complex hydrogen generation and carbon deposition reactions of methane pyrolysis both in the gas phase and within the internal substrates will be used to optimize maintenance interval and limit consumables. Honeywell will present the technical approach to integrating this technology on the International Space Station for demonstration of a fully closed-loop oxygen recovery system.Item Chemical Vapor Deposition Methane Pyrolysis Enables Closed-Loop Oxygen Recovery: Reducing System Consumables(50th International Conference on Environmental Systems, 7/12/2021) Childers, Amanda; Yates, Stephen; Brom, Nicholas; Skomurski, SeanFuture deep-space long-duration human exploration missions to Mars will require advanced oxygen recovery methods. Honeywell Aerospace is developing a methane pyrolysis technology for NASA that would recover hydrogen from the methane generated by the Sabatier unit currently used to reduce removed carbon dioxide. Complete pyrolysis of this methane to carbon increases the overall system oxygen recovery to almost 100%, while leveraging Sabatier technology. Additionally, by using high-surface area carbon capture fiber substrates, the waste carbon is non-sooty and easily handled � a technology differentiator that is vital for microgravity applications. While the fibrous substrate materials enable this performance, they also present an opportunity for continued optimization as flight implementation is considered; for a 1000-day mission, the mass of the current consumable substrates represents more than 2/3 the mass of the entire system. Minimizing the fiber volume fraction, while still ensuring non-sooty carbon deposition from methane, and maximizing substrate utilization will reduce starting mass and provide higher loading capacity, greatly reducing the overall mass and volume of the required consumable. Experimental work and alternative substrate materials have been used to identify consumable mass entitlement for enabling a fully closed-loop oxygen recovery system.Item Hydrogen Recovery by Methane Pyrolysis to Elemental Carbon(49th International Conference on Environmental Systems, 2019-07-07) Yates, Stephen; Childers, Amanda; Brom, Nicholas; Lo, Charles; Skomurski, Sean; Abney, MorganUse of a Sabatier reactor to recover the oxygen from the carbon dioxide exhaled by the crew on the International Space Station has been limited by the loss of the hydrogen contained in the methane it generates. Maximizing the oxygen recovered requires the hydrogen to be recovered from the methane product and recycled back to the Sabatier reactor. We describe the use of a tailored methane pyrolysis reactor to completely recover this hydrogen. The carbon-containing byproduct is elemental carbon, which is generated in the form of easily handled, non-sooty material that may have various uses. The effects of byproducts on Sabatier recycling was evaluated by test and compared with models based on similar catalyst material. The process of creating this tailored carbon vapor deposition process involved exploration of the effects of temperature, pressure, substrate design and other variables to develop a high yield process that cleanly generates the desired products. Reaction kinetics and kinetics modelling were used to specify the temperature, pressure and reactor volume required to achieve the target conversion and to assure that the final average density was as high as possible. Reactor design included the selection of materials that will survive the high temperatures and environment in the pyrolysis reactor, and thermal modeling to achieve the required temperatures with minimum power consumption. The successful construction and demonstration of a brassboard prototype will allow the results of the chemical, thermal and mechanical models to be validated and should provide a useful alternative for a completely closed loop ECLS system. Integration of this technology with state-of-the-art (SOA) Sabatier hardware on ISS requires a complete understanding of the effects of impurities in the product hydrogen on the Sabatier catalyst. SOA Sabatier catalyst was evaluated over short and long-term exposure to anticipated contaminants to identify effects.Item Methane Pyrolysis by CVD: Update on Development and Reaction Models(2024 International Conference on Environmnetal Systems, 2024-07-21) Parson, Abigail; Childers, Amanda; Yates, Stephen F.To close the loop in an Environmental Control and Life Support (ECLS) system that includes a Sabatier reactor to convert carbon dioxide to methane and water, a technology to recover hydrogen from the methane is required. Pyrolysis of methane to carbon and hydrogen has been demonstrated at a 4-crew scale, and can be part of a system with theoretical 100% recovery of oxygen. The hydrogen selectivity of the process is 99%. This paper provides an update on the development of a next generation flight-like advanced materials reactor that takes advantage of lightweight, non-metallic materials to convert 1.5 kg/day of methane to hydrogen and carbon with minimized power, densifying a substrate with solid, non-sooty carbon. To support design of the reactor and other system considerations, a reacting diffusion model has been developed using computational fluid dynamics (CFD) simulations of the complex hydrogen generation and carbon deposition reactions in both the gas phase and within the internal substrates. Results from this model are reported here, which predict methane conversion and how the substrate in the reactor will densify with carbon.Item Methane Pyrolysis Enables Closed-loop Oxygen Recovery - Brassboard Evaluation(2023 International Conference on Environmental Systems, 2023-07-16) Childers, Amanda; Yates, Stephen; Triezenberg, MarkMethane pyrolysis is an essential element for a closed-loop ECLS system that incorporates a Sabatier system, since this system converts carbon dioxide and hydrogen to methane and water, and the hydrogen value of the methane must be recovered to complete closure. Methane pyrolysis converts methane, at high temperature, to carbon and hydrogen. The hydrogen is required by the Sabatier reactor to completely convert the available carbon dioxide, and there are a number of re-use opportunities for the carbon. In this paper, we describe the construction and operation of a full scale brassboard methane pyrolysis reactor before it was provided to Marshall Spaceflight Center for further evaluation. The system converted methane at a 1.45 SLPM scale to carbon and hydrogen with 50-80% conversion and >95% selectivity. The effects of temperature, and substrate design were important to obtaining reliable conversion. In addition, experiments in which a feed simulating the output from a Sabatier reactor were also completed. A second generation Flight Like Advanced Materials Reactor, with similar scale but using light weight and more durable materials will also be described.