Bicarbonate intermediate and one-dimensional isothermal heterogeneous plug-flow reactor model

https://doi.org/10.1016/j.gce.2021.11.009

“Meanwhile, the mechanism of iCCC-Methane has been explored to illustrate the synergistic effect of DFMs. Cobo et al. [35] investigated the mechanism of iCCC-Methane on 5%Ru-6.1%Na₂O/Al₂O₃ DFMs by an in-situ diffuse reflectance infrared Fourier transform spectroscopy. During CO₂ adsorption, CO₂ formed a bicarbonate intermediate, then the spillover of the pre-adsorbed CO₂ on Na₂O to the adjacent metallic Ru sites was critical for enhancing the methanation yield during the conversion steps. Moreover, process modeling of iCCC can provide clear profiles of composites and temperature distributions, which are essential for the reactor design optimization and the efficiency maximization. González-Velasco’s group [36] investigated the iCCC-Methane process by using the one-dimensional isothermal heterogeneous plug-flow reactor model with axial diffusion. On the DFM of 4%Ru–10%Na₂CO₃/Al₂O₃, the distributions of gaseous CO₂, CH₄, and H₂O, as well as the solid carbonate, hydroxide and bicarbonate were illustrated along the length of the reactor, providing a deeper understanding of the mechanisms and dynamics.”