Thermally Driven Copper Oxide Redox Cycle for the Separation of Oxygen from Gases

Abstract

The copper(I) oxide (Cu2O)/copper(II) oxide (CuO) redox thermochemical cycle is thermodynamically and experimentally examined as means for removal of oxygen from dilute gas streams. The thermal energy required for removal of oxygen from a 1% O2–Ar gas mixture is estimated to range from 545 to 2121 kJ/mol O2. Temperatures as high as 1350 K imposed by this thermochemical cycle offer potential for using concentrated solar energy as the source of process heat. The kinetics of the redox reactions and their cycle-to-cycle repeatability were investigated by thermogravimetry. Laboratory scale packed bed reactor tests have pointed out the bulk shrinking of the packing during the initial high temperature cycles as a cause of gas bypassing that may have adverse effects on the reactor contacting efficiency.