Thermochemical process and compact apparatus for concentrating oxygen in extraterrestrial atmospheres: a feasibility study

The Martian atmosphere contains 0.16% oxygen, which is an example of an in-situ resource that can be used as precursor or oxidant for propellants, for life support systems and potentially for scientific experiments. Thus, the present work is related to the invention of a process to concentrate oxygen in the oxygen-deficient extraterrestrial atmosphere by means of a thermochemical process and the determination of a suitable best-case apparatus design to carry out the process. The perovskite oxygen pumping (POP) system uses the underlying chemical process, which is based on the temperature-dependent chemical potential of oxygen on multivalent metal oxide, to release and absorb oxygen in response to temperature swings. The primary goal of this work is therefore to identify suitable materials for the oxygen pumping system and to optimize the oxidation–reduction temperature and time, required to operate the system, to produce 2.25 kg of oxygen per hour under the Martian most-extreme environmental conditions and based on the thermochemical process concept. Radioactive materials such as (244)Cm, (238)Pu and (90)Sr are analyzed as a heating source for the operation of the POP system, and critical aspects of the technology as well as weaknesses and uncertainties related to the operational concept are identified.