Development Status for a Combined Solid Oxide Co-Electrolyzer and Carbon Formation Reactor System for Oxygen Regeneration

摘要

A critical component in spacecraft life support loop closure is the removal of carbon dioxide (CO_2, produced by the crew) from the cabin atmosphere and chemical reduction of this CO_2 to recover the oxygen. In 2015, we initiated development of an oxygen recovery system for life support applications consisting of a solid oxide co-electrolyzer (SOCE) and a carbon formation reactor (CFR). The SOCE electrolyzes a combined stream of carbon dioxide (CO_2) and water (H_2O) gas mixtures to produce synthesis gas (e.g., CO and H_2 gas) and pure dry oxygen as separate products. This SOCE is being developed from a NASA GRC solid oxide fuel cell and stack design originally developed for aeronautics long-duration power applications. The CFR, being developed by pHMatter LLC, takes the CO and H_2 output from the SOCE, and converts it primarily to solid carbon (C_((s))) and H_2O and CO_2. Although the solid carbon accumulates in the CFR, the innovative design allows easy removal of the carbon product, requiring minimal crew member (CM) time and low resupply mass (1.0 kg/year/CM) for replacement of the solid carbon catalyst, a significant improvement over previous Bosch reactor approaches. In this work, we will provide a status of our Phase I efforts in the development and testing of both the SOCE and CFR prototype units, along with an initial assessment of the combined SOCE-CFR system, including a mass and power projections, along with an estimate of the oxygen recovery rate.