Decomposition of CO₂ coupled with POM in a thin tubular oxygen-permeable membrane reactor

In this study, a SCFA (Al₂O₃ of 3 wt.% doped in SC_0.8F_0.2O_3-δ) dense mixed-conducting thin tubular membrane was applied to a membrane reactor for coupling the thermal decomposition of carbon dioxide (TDCD) (CO₂ ⇔ CO + 1/2O₂) with the partial oxidation of methane (POM) to syngas, in which the reaction of CO₂ decomposition took place in the tube side of the membrane and the POM reaction occurred in the shell side of the membrane simultaneously. The reaction performance of the SCFA thin tubular membrane reactor was investigated as function of reaction temperature and the feed flow rates of CO₂ and CH₄. It was found that the CO₂ conversion increased with increasing the temperature and decreased with increasing the feed flow rates of CO₂ or with decreasing the feed flow rates of CH₄. At the temperature of 900 °C, the CO₂ conversion reached about 12.4%, and the CH₄ conversion, CO selectivity and the ratio of H₂/CO were 86%, 93% and 1.8, respectively. Compared with the disc-shaped membrane, the CO₂ conversion in the thin tubular membrane is higher at the same operation temperature. The SCFA membrane reactor could be operated for about 62 h at the temperature of 900 °C.