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 SC0.8F0.2O3−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.