Lay summary
The scope of this project is to split CO2 using concentrated solar energy in a two-step cycle with metal oxide redox reactions. The first step is a high temperature process driven by concentrated solar energy where a metal oxide is converted to a lower-valence metal oxide or metal and O2. The lower-valence metal oxide or metal is then reacted with CO2 in the second, non-solar, step to produce CO and the initial metal oxide. The CO can be further processed to produce liquid fuels and the initial metal oxide is recycled back to the first step. The net reaction of the cycle is CO2=CO+0.5O2 with the CO and O2 produced in different steps, bypassing problematic gas separation. This project focuses on quantifying the maximum efficiencies of such cycles using thermodynamics, determining the rate at which reactions in the second step proceed with chemical kinetics, and designing a chemical reactor for the second cycle step. Further work will focus on modifying the second step to chemically reduce both CO2 and H2O in competitive reactions with the lower-valence metal oxide or metal to produce synthesis gas (mixtures of CO and H2).