A hybrid absorption–adsorption method to efficiently capture carbon

H. Liu, B. Liu, L.-C. Lin, G. Chen, Y. Wu, J. Wang, X. Gao, Y. Lv, Y. Pan, X. Zhang, X. Zhang, L. Yang, C. Sun, B. Smit, and W. Wang, A hybrid absorption–adsorption method to efficiently capture carbon Nat. Commun. 5, 5147 (2014) http://dx.doi.org/10.1038/ncomms6147


Abstract Removal of ​carbon dioxide is an essential step in many energy-related processes. Here we report a novel slurry concept that combines specific advantages of metal-organic frameworks, ion liquids, amines and membranes by suspending zeolitic imidazolate framework-8 in glycol-2-methylimidazole solution. We show that this approach may give a more efficient technology to capture ​carbon dioxide compared to conventional technologies. The ​carbon dioxide sorption capacity of our slurry reaches 1.25 mol l−1 at 1 bar and the selectivity of ​carbon dioxide/​hydrogen, ​carbon dioxide/​nitrogen and ​carbon dioxide/​methane achieves 951, 394 and 144, respectively. We demonstrate that the slurry can efficiently remove ​carbon dioxide from gas mixtures at normal pressure/temperature through breakthrough experiments. Most importantly, the sorption enthalpy is only −29 kJ mol−1, indicating that significantly less energy is required for sorbent regeneration. In addition, from a technological point of view, unlike solid adsorbents slurries can flow and be pumped. This allows us to use a continuous separation process with heat integration.

© Berend Smit 2019