Browsing by Author "Dennis,Brian"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Comprehensive Digital Twin of a Microfluidic Electrochemical Reactor to Optimize the Electrochemical-based Recovery of O2 from Metabolic CO2(2024 International Conference on Environmnetal Systems, 2024-07-21) Dominguez, Jesus A.; McCall, Shannon; Reidy, Lorlyn; Nur, Mononita; Brown, Brittany; Dennis,Brian; Chanmanee, Wilaiwan; Fillion,Joseph; Ollenburg, KathrynFuture long-duration missions will require a sustainable and efficient system capable of yielding a minimum of 75% O2 recovery from metabolic CO2 to achieve self-sufficiency for long space missions beyond Earth's low orbit. A Microfluidic Electrochemical Reactor (MFECR) development effort to electrochemically recover O2 from CO2 is underway at NASA Marshall Space Flight Center (MSFC) to increase current O2 recovery efficiency and reduce air revitalization (AR) system complexity at the International Space Station (ISS) habitat and future long missions. The authors have developed and deployed a comprehensive 3D multiphysics model that thoroughly replicates the actual configuration and fluid/material domains of the MFECR. This model's electrochemical physics consists of multicomponent-multiphase electrochemical-driven reactions leading to CO2 conversion to C2H4 and CO along with the formation of H2 on the cathode in parallel with the generation of O2 and H2O on the anode. This electrochemical model is coupled with all the physics phenomena involved in the process, including but not limited to fluid and non-ideal mass transfer of reactant and product species in free/porous media, convective/conduction/radiative heat transfer, and conduction of DC electrical current with Joule heating generation. The model has proved to be an essential optimization tool using the O2 conversion from CO2 as the objective function and the dimensions of three different Engineering Design Unit (EDU) geometry layouts and two inlet process conditions as input variables. The three MFECR geometry layouts include one without serpentine paths (plain) and two with serpentines leading to four and twelve paths, respectively. The two inlet process conditions include CO2 flow rate and temperature. The MFECR's test stand is fully automated and equipped with several inline measurements (flow, pressure, temperature, pH, component concentration) systems on all six MFECR's IO streams, allowing reliable experimental validation of the model and parametric determination of all electrochemical reactions.Item Reliable and Efficient Electrochemical Recovery of O2 from Metabolic CO2 at the International Space Station (ISS)(2024 International Conference on Environmnetal Systems, 2024-07-21) Dominguez, Jesus A.; Reidy, Lorlyn; Nur, Mononita; Crawford, Kagen; Brown, Brittany; Dennis,Brian; Chanmanee, Wilaiwan; Fillion,Joseph; Ollenburg, Kathryn; McCall, ShannonMaximum oxygen (O2) recovery from metabolic carbon dioxide (CO2) is desired for future long-duration missions beyond Low Earth Orbit. The O2 recovery for the Environmental Control and Life Support System (ECLSS) at the International Space Station (ISS), presently limited to 50% (Sabatier), must be highly reliable and efficient and recover a minimum of 75% O2 from metabolic CO2. An alternative technology development effort currently underway at NASA Marshall Space Flight Center via a Macro-fluidic Electrochemical Reactor (MFECR) approach has the potential to increase O2 recovery significantly and reduce the complexity of the ECLSS O2 recovery at the ISS as it would replace three pieces, the CO2 Reduction Assembly (CRA) (Sabatier reactor), the Oxygen Generation Assembly (OGA), and the Plasma Pyrolysis Assembly (PPA). The MFECR's electrochemical process generates ethylene (C2H4) and carbon monoxide (CO) instead of methane (CH4) (Sabatier) as a byproduct, eliminating the need for further dehydrogenation through the PPA. As in the OGA, the MFECR's electrochemical process generates O2 and hydrogen (H2) from the water electrolysis process. MSFC and the University of Texas in Arlington have jointly designed and fabricated/upgraded an MFECR's single cell that operates at ambient conditions and utilizes a catalyst highly selective on reducing CO2 to C2H4 and CO at the cathode. This approach is expected to substantially improve the ISS ECLSS sustainability and reduce power and weight requirements as the MFECR would replace three and potentially four units currently installed in the ISS. In this paper, the authors discuss the outcome of preliminary tests, the current development, the evaluation efforts on different alternatives for the cathode and the anode configurations, the use of MFECR's digital twin to upgrade its design at an engineering development unit (EDU) scale, and the evaluation efforts on different electrolyte alternatives and alkalinity effect.