Energy Technology · 2015 · 50 citations · 44 references
The continuous production of carbon monoxide (CO) and hydrogen (H<sub>2</sub>) by dry reforming of methane (CH<sub>4</sub>) is demonstrated isothermally using a ceramic redox membrane in absence of additional catalysts. The reactor technology realizes the continuous splitting of CO<sub>2</sub> to CO on the inner side of a tubular membrane and the partial oxidation of CH<sub>4</sub> with the lattice oxygen to form syngas on the outer side. La<sub>0.6</sub>Sr<sub>0.4</sub>Co<sub>0.2</sub>Fe<sub>0.8</sub>O<sub>3-<i>δ</i></sub> (LSCF) membranes evaluated at 840-1030 °C yielded up to 1.27 μmol <sub>CO</sub> s<sup>-1</sup> from CO<sub>2</sub>, 3.77 μmol<sub>H₂</sub> g<sup>-1</sup> s<sup>-1</sup> from CH<sub>4</sub> , and CO from CH<sub>4</sub> at approximately the same rate as CO from CO<sub>2</sub>. We compute the free energy of the oxygen vacancy formation for La<sub>0.5</sub>Sr<sub>0.5</sub>B<sub>0.5</sub>B'<sub>0.5</sub>O<sub>3-<i>δ</i></sub> (B, B'=Mn, Fe, Co, Cu) using electronic structure theory to understand how CO<sub>2</sub> reduction limits dry reforming of methane using LSCF and to show how the CO<sub>2</sub> conversion can be increased by using advanced redox materials such as La<sub>0.5</sub>Sr<sub>0.5</sub>MnO<sub>3-<i>δ</i></sub> and La<sub>0.5</sub>Sr<sub>0.5</sub>Mn<sub>0.5</sub>Co<sub>0.5</sub>O<sub>3-<i>δ</i></sub> .
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