The following content is related to the use of two beds to realise continuous ICCU-RWGS, by switching gases, and copied from https://doi.org/10.1021/acscatal.1c05339.
“A long-term continuous CCR operation was performed using two fixed-bed flow reactors (reactor A and B). A 300 mg sample of Pt–Na/Al2O3 was placed on quartz wool in the middle for both reactors. Two side tubings were filled with sea sand. Two timer-control 4-way valves on the top and bottom of the reactors were switched simultaneously to continuously change the two gases for CCR and collect the two effluent gases. Both reactors set in the electric tube furnace were heated to 350 °C under a N2 flow (90 mL/min). Subsequently, 10% H2/N2 (100 mL/min) was introduced to each reactor for pretreatment for 20 min at 350 °C. Next, 100 mL/min 0.5% CO2/10% O2/N2 was fed to reactor A for 30 s, after which the gas was switched to 100 mL/min H2 for another 30 s. Contrastingly, 100 mL/min pure H2 was fed to reactor B for 30 s, and then, the gas was switched to 100 mL/min 0.5% CO2/10% O2/N2 for another 30 s. The effluent gases containing uncaptured CO2 (effluent 1) and generated CO, CH4, and desorbed CO2 (effluent 2) were continuously collected from each outlet line. The compositions of two effluent gases were continuously analyzed by performing FTIR spectroscopy (JASCO FT/IR-4600) with gas cells. The background spectrum was measured after H2 pretreatment followed by N2 purge. This gas switching was repeated for 6000 cycles to evaluate the long-term durability for 100 h.”