Lei, Timan;
Luo, Kai H;
Perez, Francisco E Hernandez;
Wang, Geng;
Yang, Junyu;
Cano, Juan Restrepo;
Im, Hong G;
(2024)
Pore-scale study of CO2 desublimation and sublimation in a packed bed during cryogenic carbon capture.
Journal of Fluid Mechanics
, 990
, Article A6. 10.1017/jfm.2024.351.
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Abstract
Cryogenic carbon capture (CCC) is an innovative technology to desublimate CO2 out of industrial flue gases. A comprehensive understanding of CO2 desublimation and sublimation is essential for widespread application of CCC, which is highly challenging due to the complex physics behind. In this work, a lattice Boltzmann (LB) model is proposed to study CO2 desublimation and sublimation for different operating conditions, including the bed temperature (subcooling degree ∆Ts), gas feed rate (Péclet number Pe) and bed porosity (ψ). The CO2 desublimation and sublimation properties are reproduced. Interactions between convective CO2 supply and desublimation/sublimation intensity are analysed. In the single-grain case, Pe is suggested to exceed a critical value Pec at each ∆Ts to avoid the convection-limited regime. Beyond Pec, the CO2 capture rate (vc) grows monotonically with ∆Ts, indicating a desublimation-limited regime. In the packed bed case, multiple grains render the convective CO2 supply insufficient and make CCC operate under the convection-limited mechanism. Besides, in small-∆Ts and high-Pe tests, CO2 desublimation becomes insufficient compared with convective CO2 supply, thus introducing the desublimation-limited regime with severe CO2 capture capacity loss (ηd). Moreover, large ψ enhances gas mobility while decreasing cold grain volume. A moderate porosity ψc is recommended for improving the CO2 capture performance. By analysing vc and ηd, regime diagrams are proposed in ∆Ts–Pe space to show distributions of convection-limited and desublimation-limited regimes, thus suggesting optimal conditions for efficient CO2 capture. This work develops a viable LB model to examine CCC under extensive operating conditions, contributing to facilitating its application.
| Type: | Article |
|---|---|
| Title: | Pore-scale study of CO2 desublimation and sublimation in a packed bed during cryogenic carbon capture |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1017/jfm.2024.351 |
| Publisher version: | https://doi.org/10.1017/jfm.2024.351 |
| Language: | English |
| Additional information: | This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited. |
| Keywords: | Convection in porous media, solidification/melting, coupled diffusion and flow |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10199840 |
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