ICCU-DRM have two key stages, including CO2 capture and the utilisation of the captured CO2 (or sorbent regeneration). Therefore, reaction time plays a key role in practice. In general, during CO2 capture, a short reaction time is mainly related to fast capture. Too long reaction time will be related to slow reaction kinetics. The formed carbonate (e.g. CaCO3) might be different at different reaction stages. To our knowledge, the carbonate generated at the fast carbonation stage is easier to be regenerated compared to that generated at the slow carbonation stage.
In terms of the regeneration stage (CO2 utilisation), the process depends on the availability of CO2, corresponding to the capacity of dual functional materials. However, the regeneration time should be sufficient in order to return to the initial state of dual functional materials.
The following content about the influence of reaction temperature on ICCU-DRM is from this reference (https://doi.org/10.1016/j.ccst.2022.100052).
“The reaction duration also plays an important role in the ICCC-DRM performance. Kim et al. (Kim et al., 2018) have investigated the effect of sorption time and the subsequent dry reforming time on the ICCC-DRM performance using Ni/MgO-Al2O3-limestone in a fluidized bed reactor, and found that the CO2 uptake of the material was initially increased rapidly with the increase of the sorption duration, while it reached a plateau after about 12 min when the reaction turned from the fast reaction stage controlled kinetically to the slow reaction stage controlled by product layer diffusion. Besides, the ratio of H2 to CO is approximately 1.1 during the initial 15 min of the DRM process, while it increased rapidly afterwards due to significant coking.”
“DRM is highly endothermic process and high temperatures (800−900°C) are needed to achieve equilibrium conversion. In contrast, dry reforming of ethane (DRE, as shown in Eq. 4), which is operated at slightly lower temperatures, i.e., 100 °C below that of DRM, has been investigated recently. Al-Mamoori et al. (Al-Mamoori et al., 2018) proposed an ICCC process that couples the CO2 capture and in-situ dry reforming of ethane, i.e., ICCC-DRE, at 650 °C using Ni20@(K-Ca)50/(γ-Al2O3)50, and observed that it illustrated a relatively stable performance during 600 min of reaction, with only a 5% drop in activity. This study provided insights to the dry reforming of hydrocarbons other than CH4 in the ICCC-DR process.”