Supported molten-salt membranes for carbon dioxide permeation

Abstract

First review of supported molten-salt membranes highlighting materials challenges, mechanistic development and manufacturing opportunities towards energy applications.

Dendritic silver self-assembly in molten-carbonate membranes for efficient carbon dioxide capture

“…Dual-phase membranes offer outstanding CO 2 /N 2 selectivity (41000) as the solubility of CO 2 in molten carbonate is B10 4 higher than N 2 . 38,52 As N 2 is only detected on the permeate side of a dual-phase membrane as the result of a leak, selectivity is routinely calculated based on solubilities alone. Here, we have adopted a more conservative approach and calculated a minimum selectivity based on the limit of detection of our analytical apparatus (Experimental methods text, ESI †).…”

“…For a more detailed discussion of mechanistic concerns, the reader is referred to a recent review article on this class of membrane. 38 Regardless, ceramic-carbonate membranes and metal-carbonate membranes are most applicable to pre-and post-combustion CO 2 capture, respectively, due to the requirement for O 2 in the latter case. The first reported metal-carbonate membranes were fabricated from porous stainless-steel infiltrated with MC, 30 with CO 2 and O 2 fluxes stabilising at a level lower than that predicted by reaction (2).…”

CO2 capture using solid sorbents: Fundamental aspects, mechanistic insights and recent advances

“…It is well known from CO2 transport membranes that the immobilization of the molten alkali metal carbonate phases strongly depends on the microstructure of the host structure (here: CaO) and the physical properties of the molten carbonates, e.g. the wettability [333]. Capillary forces, which decrease with increasing pore diameter, need to be high to withhold the molten alkali metal carbonates, and so sintering is expected to contribute to the loss of the alkali metals [334].…”

“…Triviño et al [597] showed that the immobilization of eutectic salts within the sorbent can be achieved through core-shell MgO fibers. Valuable lessons may be learned also from high temperature CO2-conducting membranes, where the molten carbonate needs to be retained within the porous solid matrix [333], [598]- [601].…”

Ceria-Based Dual-Phase Membranes for High-Temperature Carbon Dioxide Separation: Effect of Iron Doping and Pore Generation with MgO Template

“…Fe is also known to decrease the densification temperature of the SDC system [19,20] by inducing viscous flow sintering [21]. Use of sacrificial materials, e.g., NiO template [16], allows for control of the pore volume, size, connectivity, and tortuosity, having a strong influence on the CO 2 permeability [22]. Other studies relied on the use of MgO as a sustainable, safer and cheaper alternative to metal-containing templates as a hard template for Ag–CGO porous cermets for solid oxide fuel cells [23].…”