Thermally-Driven Oxygen Pumping and Sweeping/Separation

One of the key challenges in solar thermochemical (STC) fuels production is to minimize oxygen partial pressures in the thermal reduction step. This partial pressure must be reached by energetically efficient and economically affordable methods—currently unavailable by either vacuum pumping or inert gas sweeping. In an effort to address this unresolved high impact challenge in STC fuels, we have analyzed and experimentally tested a promising new thermally driven approach, featuring high theoretical efficiencies, comparatively low operating temperatures, and exceedingly simple and robust devices—including implementations without moving parts. Our results shows that, even under conservative practical assumptions, the thermally driven pumping and sweeping/separation approach has the potential to substantially exceed state of the art approaches, especially in the low pressure regime, and do so in inherently simple and potentially low cost devices.