Energy Efficient Microlith®-based Catalytic Reactor and Recuperator for Air Quality Control Applications

Precision Combustion, Inc. (PCI) and NASA – Marshall (MSFC) have been developing, characterizing, and optimizing high temperature catalytic oxidizers (HTCO) based on PCI’s patented Microlith® technology to meet the requirements of future extended human spaceflight explorations. Previous efforts focused on integrating the HTCO unit with a compact, simple recuperative heat exchanger to reduce the overall system size and weight. Significant improvement was demonstrated over traditional approaches of integrating the HTCO with an external recuperative heat exchanger. While the critical target performance metrics were achieved, the thermal effectiveness of PCI’s recuperator remained a potential area of improvement to further reduce the energy requirements of the integrated system. Using the same material combinations and an improved recuperator design, the 2nd generation prototype has experimentally demonstrated 20 – 30% reduction (flow dependent) in the steady state power consumption, in comparison to the 1st Generation prototype, without compromising the destruction efficiency of methane and volatile organic compounds (VOCs). Moreover, design modifications and improvements allow our prototype to be more easily manufactured compared to traditional brazed plate-fin recuperator designs. The 2nd Generation prototype was delivered to NASA-MSFC for validation testing. Here, we report and discuss the performance of the improved HTCO unit with a high efficiency recuperative heat exchanger based on testing at PCI and NASA-MSFC. The device is expected to provide a reliable and robust means of disposing of trace levels of methane and VOCs by converting them into carbon dioxide and water in order to maintain clean air in enclosed spaces, such as crewed spacecraft cabins.