Dr Qin’s group investigated ICCU-DRM using K-Li4SiO4 mixed with Ni/Al2O3 as the dual functional materials (https://doi.org/10.1016/j.seppur.2021.119476). Ten cycles of ICCU was reported. The following content was copied from the above reference.
“Based on the optimal coupling temperature of 625 °C, the cyclic performance of ICCU-DRM using K-Li4SiO4 and Ni/Al2O3 was further tested and characterized. The reaction curves at the 1st, 5th, and 10th cycle are exhibited in Fig. 5(a). In the CO2 capture stage of the 5th, and 10th cycle, the generation of CO gas is observed on account of the removal of carbon deposits (CO2+C→2CO) on the catalyst, which mainly comes from methane decomposition of the previous cycle [6]. The ratio of H2/CO and the molar flow velocities of H2 and CO as a function of cycle number are further displayed in Fig. 5(b-d). It is noticed that the duration of pre-breakthrough stage is increased from 7 min in the 1st cycle to 11 min in the 10th cycle from Fig. 5(b), indicating an excellent matching and stability of the material system of Ni/Al2O3 and K-Li4SiO4. Fig. 5(c) demonstrates three nearly overlapping curves of H2 molar flow velocity in relation to the 1st, 5th and 10th cycle of ICCU-DRM indicating that the catalyst possesses an excellent cyclic stability during ICCU-DRM process. Furthermore, Fig. 5(d) depicts that the molar flow velocity of CO in the 5–20 min stage rises as growing the number of cycles, which should be credited to the gradual activation of the sorbent in the first five cycles. Meanwhile, the conversion of CO2 during breakthrough stage increases from 81% to 84%, though there is a slight reduction in the conversion of CH4 from 95% to 94%. Additionally, though there is a little lower CO2 conversion than the reported 96.3% at 720 °C by lime and Ni/MgO-Al2O3 in the work of Kim et al. [6], a much superior stability on the CO2 capacity, pre-breakthrough duration and H2/CO ratio in the cyclic reactions is demonstrated in the work. More information on the comparison of our work with the results in the literature can be found in Table S2.”
“Fig. 5. (a) ICCU-DRM at the1st, 5th and 10th cycle; (b) H2/CO ratio of the effluent gas; (c) molar flow rate of H2; (d) molar flow velocity of CO.” (https://doi.org/10.1016/j.seppur.2021.119476)
