Microstructural and Interfacial Designs of Oxygen‐Permeable Membranes for Oxygen Separation and Reaction–Separation Coupling

Abstract

Mixed ionic–electronic conducting oxygen‐permeable membranes can rapidly separate oxygen from air with 100% selectivity and low energy consumption. Combining reaction and separation in an oxygen‐permeable membrane reactor significantly simplifies the technological scheme and reduces the process energy consumption. Recently, materials design and mechanism investigations have provided insight into the microstructural and interfacial effects. The microstructures of the membrane surfaces and bulk are closely related to the interfacial oxygen exchange kinetics and bulk diffusion kinetics. Therefore, the permeability and stability of oxygen‐permeable membranes with a single‐phase structure and a dual‐phase structure can be adjusted through their microstructural and interfacial designs. Here, recent advances in the development of oxygen permeation models that provide a deep understanding of the microstructural and interfacial effects, and strategies to simultaneously improve the permeability and stability through microstructural and interfacial design are discussed in detail. Then, based on the developed high‐performance membranes, highly effective membrane reactors for process intensification and new technology developments are highlighted. The new membrane reactors will trigger innovations in natural gas conversion, ammonia synthesis, and hydrogen‐related clean energy technologies. Future opportunities and challenges in the development of oxygen‐permeable membranes for oxygen separation and reaction–separation coupling are also explored.

Effects of Bi Substitution on the Cobalt-Free 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe1−xBixO3−δ Oxygen Transport Membranes

“…The OTMs obtained from the optimal temperature all show a suitable density (>90%) and a uniform dual-phase distribution. Compared with the OTMs obtained by the high-temperature solid-state method, there could be more continuous conductive networks and active sites in the interface for the oxygen exchange reaction, which might improve the oxygen permeability [45,46].…”

High‐performance oxygen transport membrane reactors integrated with IGCC for carbon capture

“…Praxair Inc. has made great progress on the commercialization of the OTM reactor for the conversion of natural gas to syngas. They started a project to produce 9,940 N m 3 hr −1 syngas for a methanol plant using an OTM reactor in 2019 40,41 . In the hydrogen separation/production application, two sides of the OTM are both under strong reducing atmospheres.…”

“…They started a project to produce 9,940 N m 3 hr −1 syngas for a methanol plant using an OTM reactor in 2019. 40,41 In the hydrogen separation/production application, two sides of the OTM are both under strong reducing atmospheres.…”

Synthesis and Characterization of 40 wt % Ce0.9Pr0.1O2–δ–60 wt % NdxSr1−xFe0.9Cu0.1O3−δ Dual-Phase Membranes for Efficient Oxygen Separation

“…For example, plasma-assisted MIEC membranes, used to separate oxygen radicals without additional external heating from the decomposition products, provide an efficient way to enhance the overall CO 2 conversion efficiency via inhibiting the reverse reactions [ 27 , 28 ]. Traditional OTMs, which have been intensively investigated in recent years, are usually Ba 2+ - or Sr 2+ -containing perovskite-type oxides, such as Ba 1− x Sr x Co 1− y Fe y O 3− δ , which show excellent oxygen permeabilities [ 4 , 5 , 34 , 35 , 36 , 37 , 38 , 39 ]. However, due to their vulnerability in CO 2 -containing environments, the widespread industrial applicability is strongly limited [ 1 , 4 ].…”