Chemical looping syngas from CO 2 and H 2 O over manganese oxide minerals

Rather than sequestering carbon dioxide from the exhaust of chemical looping combustion reactors, together with the water, it could be used as a source of syngas. For the first time, we split water to hydrogen and carbon dioxide to carbon monoxide with a manganese ore. Specific CO production is 10–100 times higher than Sr, Ce, and Fe doped perovskites and Y 0.5 Sr 0.5 MnO 3 perovskites. At a contact time of 0.01 s and at temperatures ranging from 810–960 °C the maximum specific CO production was 5.5mol · kg − 1 . A combined kinetic‐axial dispersion hydrodynamic model accounts for 97 % of the variance in the data assuming the reaction rate is first‐order in CO 2 and surface reduced sites and in equilibrium with the reverse reaction—a first‐order reaction in CO with surface oxidized sites. A second reaction accounts for the diffusion of surface oxygen to the bulk lattice. Hydrogen productivity peaked at 4.8mol · kg − 1at 947 °C, which is twice as high as reported in previous studies on CoFe 2 O 4 and Al 2 O 3 in the hercynite cycle.