Chemical Engineering Research & Design, Vol.89, No.9A, 1533-1543, 2011
Carbon capture and utilization via chemical looping dry reforming
Chemical looping combustion (CLC) is a clean energy technology for CO2 capture that uses periodic oxidation and reduction of an oxygen carrier with air and a fuel, respectively, to achieve flameless combustion and yield sequestration-ready CO2 streams. While CLC allows for highly efficient CO2 capture, it does not, however, provide a solution for CO2 sequestration. Here, we propose chemical looping dry reforming (CLDR) as an alternative to CLC by replacing air with CO2 as the oxidant. CLDR extends the chemical looping principle to achieve CO2 reduction to CO, which opens a pathway to CO2 utilization as an alternative to sequestration. The feasibility of CLDR is studied through thermodynamic screening calculations for oxygen carrier selection, synthesis and kinetic experiments of nanostructured carriers using cyclic thermogravimetric analysis (TGA) and fixed-bed reactor studies, and a brief model-based analysis of the thermal aspects of a fixed-bed CLDR process. Overall, our results indicate that it is indeed possible to reduce CO2 to CO with high reaction rates through the use of appropriately designed nanostructured carriers, and to integrate this reaction into a cyclic redox ("looping") process. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords:Chemical looping;CO2 utilization;Nanomaterials;Fixed bed reactors;Periodic reactor operation