Simultaneous CO₂ and O₂ separation coupled to oxy-dry reforming of CH₄ by means of a ceramic-carbonate membrane reactor for in situ syngas production

It is reported the use of a ceramic-carbonate membrane exhibiting CO₂ and O₂ permeation, coupled with the oxy-carbon dioxide reforming of methane to produce syngas in a membrane reactor arrangement. The studied membrane is made of a porous fluorite/perovskite mixed conducting ceramic infiltrated with molten carbonates. The CO₂ and O₂ gas mixture used to perform the oxy-dry reforming process is the membrane's permeate, which reacts with CH₄ supplied in the sweep gas with the assistance of a catalyst. The reactor converts from 74 to 99% of CH₄ under the studied separation and reaction conditions. The total rate of syngas production reaches 6.25 mL∙min⁻¹∙cm⁻² at 875 °C and a H₂/CO ratio ranging from 2.1 to 1.3 between 800 and 875 °C. A long-term test shows a stable performance for 300 h. This work suggests the feasibility of this capture-conversion concept for the valorization of CO₂ by the efficient production of syngas.