Chemical looping combustion (CLC) has been demonstrated as a clean combustion technology, which produces high purity, high-pressure, sequestration-ready CO2 streams from both fossil and renewable fuels. CLC is based on a two reactor concept in which flameless, NOx-free combustion is achieved by contacting a fuel with a solid oxygen carrier material in the first reactor, followed by the re-oxidation of the carrier with air in the second reactor. However, while CLC is a highly efficient technology for CO2 capture, it does not present a solution to CO2 sequestration.

Here, an alternate chemical looping concept, Chemical Looping Dry Reforming (CLDR), is proposed. In CLDR, air is replaced by CO2 as the oxidizing gas. This process thus results in the catalytic activation of CO2 via reduction to CO and thus potentially opens a novel pathway towards CO2 utilization.

We will present results from a feasibility study, which includes thermodynamic screening for potential oxygen carriers, synthesis and characterization of promising nanostructured carriers, and kinetic testing of select carrier materials in cyclic thermal gravimetric analysis (TGA) and fixed-bed reactor studies. Our results indicate that it is indeed possible to reduce CO2 to CO with high reaction rates even at very mild temperatures (as low as 200oC) via use of appropriately designed nanostructured carriers, and to integrate this step into a cyclic redox (“looping”) process as described above.