ICCU concept has been used to produce syngas through the combination with dry ethane reforming (DER). DER requires lower temperatures compared to dry methane reforming, benefiting the selection of catalysts. Ni/K-Ca/Al2O3 dual functional materials were applied for this process at 650 °C, and near 100% ethane conversion was obtained (https://doi.org/10.1021/acssuschemeng.8b03769). However, the conversion of CO2 was less than 70%. However, this DFM showed a relatively low capacity of CO2 adsorption (~1 mmol/g). The low adsorption capacity might be due to the low concentration of Mg or Ca elements in the DFMs. Coke deposition was clearly observed in this work, although the DFMs showed relatively stable performance over 600 mins with about 5% drop in activity.
DFMs were also used for ICCU and ethane to ethylene conversion (https://doi.org/10.1016/j.apcatb.2020.119329). The DFMs consist of K promoted CaO sorbent and Cr-doped H-ZSM-5. This ICCU process was carried out under non-isothermal conditions including the adsorption at 600 C using 10%CO2 and the desorption/conversion at 700 C using 5% C2H6. The capacity of CO2 adsorption was 5.3 mmol/g, and the conversion of C2H6 was about 25%, with the ethylene selectivity of 88%. Four ICCU cycles were performed. However, the capacity of CO2 capture was significantly reduced (as shown below).
https://doi.org/10.1016/j.apcatb.2020.119329
The authors concluded with the following statement:
“Overall, this study demonstrated the utility of a combined capture-utilization process for producing light olefins directly from waste CO2. Assuming that the materials are further optimized, they could be utilized as a novel route for CO2 utilization and manufacturing of value-added commodities. To improve the performance of the combined process, future works should be directed toward enhancing the catalytic activity and the use of real flue gas as the source of CO2.”