Browsing by Author "Bonk, Ted"
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Item Carbon Dioxide Removal by Ionic Liquid Sorbent (CDRILS) System Development(48th International Conference on Environmental Systems, 2018-07-08) Henson, Phoebe; Yates, Stephen; Kamire, Rebecca; Bonk, TedUsing a liquid absorbent like an ionic liquid eliminates many of the disadvantages of solid adsorbent systems for carbon dioxide (CO2) removal from air in a deep space mission. Systems built around a liquid absorbent avoid complicated valve networks to switch between absorbing and desorbing beds, and deliver an even flow of product carbon dioxide. Ionic liquids are particularly desirable for space applications since they are non-volatile, non-odorous, and have high oxidative stability. Significant progress has been made in the development of the CDRILS system for use in life support applications. Membrane contactors have been designed that provide high surface area without allowing escape of the liquid, and the long-term reliability of both contactors and ionic liquid has been assessed. Using measured CO2 and water capacities and mass transfer coefficients, alternative system designs have been evaluated to identify those that maximize performance while minimizing weight, volume and power consumption. Because water is strongly absorbed by most ionic liquids, water management is a key focus in designing the closed-loop system. Determination of optimized operating conditions and the optimum system design allows scale up of lab scale experiments to a full size unit capable of removing 4.16 kg/day of CO2.Item Carbon Dioxide Removal by Ionic Liquid System (CDRILS): Continuous Operation and Full-Scale Brassboard Testing(50th International Conference on Environmental Systems, 7/12/2021) Henson, Phoebe; Kamire, Rebecca; Yates, Stephen; Skomurski, Sean; Zaki, Rehan; Bonk, Ted; Loeffelholz, DavidThe Carbon Dioxide Removal by Ionic Liquid System (CDRILS) is a light weight, low volume CO2 management technology for air revitalization in commercial and long duration human space missions. CDRILS is based on continuous recirculation of an ionic liquid sorbent between hollow fiber scrubber and stripper contactors. This paper reports further progress in advancing the Technology Readiness Level of the technology. A fully integrated lab-scale CDRILS has been built for an extended durability trial under continuous operation, and in-progress results are reported on its performance. A second CDRILS capable of operating full-scale hollow fiber contactors has also been built, and larger scale integrated scrubber-stripper studies are discussed. Preliminary work has probed the potential for the CDRILS to perform a trace contaminant control function in addition to CO2 and humidity management. Ongoing stability studies on the ionic liquid and membrane contactor components have now reached the 2-year milestone and continue to show little or no degradation of these materials. An updated estimate for system size, weight, and power and prototype design are also presented.Item A Closed-Loop CO2 and Humidity Recovery System for Deep Space Missions(47th International Conference on Environmental Systems, 2017-07-16) Henson, Phoebe; Yates, Stephen; Bonk, Ted; Bershitsky, Alexander; Kamire, Rebecca; Isobe, JunCarbon dioxide (CO2) removal is a critical component of life support systems used in human spacecraft and the International Space Station. Long-duration missions into deep space and to Mars will require a CO2 removal system with higher performance, higher reliability, and the ability to recover the CO2 for recycling back into oxygen, rather than discarding it to space. In the past, solid adsorbents have been used for CO2 removal. However, liquid absorbents have significant advantages over solid adsorbents. The ability to pump the absorbent from scrubber to stripper stages allows for continuous processing, which is generally more stable and reliable than batch processing used in solid adsorbent systems, and eliminates complicated valve networks. Using direct liquid contact, in which the CO2 is contacted with small liquid droplets, allows higher surface area and thus a system of lower estimated volume. Liquid may also be easily exchanged into the system without disassembly. Amine-based systems like those used in submarines are prone to outgassing of dangerous and odorous products, air oxidation, thermal degradation, and can be corrosive. Safe, stable ionic liquids allow the highly reliable and effective liquid absorbent system to be used in a human space environment. With numerous ionic liquids available, the ionic liquid can be tailored for stability and a high CO2 capacity. Ionic liquids are also readily miscible with water, but, at the relative humidity concentrations of a spacecraft, water absorption will not have a strong negative effect on CO2 capacity. This, along with the stability of ionic liquid with water, enables the system to act as a humidity removal system as well. Progress in developing a compact combined CO2 and humidity recovery system using ionic liquids and direct liquid contact will be described. Approaches to maximizing absorption and desorption kinetics lead to attractive estimated device volumes.Item An Environmental Control and Life Support System (ECLSS) for Deep Space and Commercial Habitats(50th International Conference on Environmental Systems, 7/12/2021) Henson, Phoebe; Yates, Stephen; Dotson, Breydan; Bonk, Ted; Finger, Barry; Kelsey, Laura; Junaedi, Christian; Rich, MeaganLong-duration missions to the Moon, Mars, and beyond require an Environmental Control and Life Support System (ECLSS) to have increased performance, reliability, and resiliency while still meeting mission safety requirements and remaining within volume, mass, power, cooling, and crew-time constraints. The Commercial ECLSS is an improved alternative to the baseline ECLSS technology used on the International Space Station (ISS). By combining new technologies developed and matured by Honeywell, Precision Combustion, Giner, and Paragon, the Commercial ECLSS addresses multiple capability and reliability gaps for the long-duration crewed missions described by NASA. With higher oxygen and water recovery rates, a spacecraft utilizing the Commercial ECLSS will require minimal-to-no resupply mass, which translates to significant cost savings over the course of long missions. This paper describes the team�s conceptual ECLSS architecture and identifies the significant capability and reliability gaps closed from the ISS ECLSS. Additionally, it illustrates how by avoiding the many failure modes faced by the ISS ECLSS and by incorporating modern technologies into the system, the Commercial ECLSS offers a safer, more reliable, and more cost-effective solution for commercial and NASA customers.Item Scale-up of the Carbon Dioxide Removal by Ionic Liquid Sorbent (CDRILS) System(2019-07-07) Henson, Phoebe; Kamire, Rebecca; Yates, Stephen; Bonk, Ted; Loeffelholz, David; Zaki, Rehan; Fox, Eric; Kaukler, William; Henry, ChristopherThe Carbon Dioxide Removal by Ionic Liquid Sorbent (CDRILS) system is designed for efficient, safe and reliable carbon dioxide (CO2) removal from cabin air on long-duration missions to the Moon, deep space, and Mars. CDRILS integrates an ionic liquid sorbent with hollow fiber membrane contactors for rapid CO2 removal and recovery. The liquid-based system provides continuous CO2 delivery, which avoids complicated valve networks to switch between absorbing and desorbing beds and enables simpler integration to the Sabatier without the need for the CO2 Management System (CMS). Ionic liquids are particularly desirable as liquid absorbents for space applications since they are non-volatile, non-odorous, and have high oxidative stability. The hollow fiber membrane contactors offer both high contact area and rigorous containment between the gas and liquid phases in a microgravity environment. Scale-up of the CDRILS technology has presented a series of fascinating challenges, since the interaction between hollow fiber properties, ionic liquid properties and performance is complex. Properties measured with lab-scale hollow fiber contactors are used to estimate the performance of contactors that are similar in size and form factor to those to be used in flight-scale demonstrations. To accomplish this, component and system models have been built to relate the key scrubber and stripper design and operating variables with performance, and experiments directed to validate the models have been performed. System size, weight and power are all sensitive to component selection, arrangement, operating conditions and scaling. Reliability will be extremely important for any long-range mission and depends critically on the stability of the ionic liquids and of the scrubber and stripper contactors. We will report on our continuing long term stability experiments for the ionic liquid and contactor materials, and our investigation of the physical properties of additional ionic liquids.