Membrane Gas Separation Technologies

Membrane gas separation harnesses thin, selective barriers to discriminate between gas species, offering energy‐efficient alternatives to conventional cryogenic and adsorption processes. Central to performance are two attributes: permeability, the rate at which a gas traverses the membrane under a pressure gradient, and selectivity, the relative passage of one species over another. Membranes may be organic polymers, inorganic ceramics or emerging hybrids such as mixed‐matrix systems blending polymers with porous fillers. Advances in materials chemistry have yielded rigid, microporous polymers and two‐dimensional nanosheets with uniform subnanometre channels that approach or surpass classical performance limits. Metal–organic frameworks (MOFs) and hydrogen‐bonded organic frameworks (HOFs) integrated into membranes can enhance sorption and molecular sieving, while surface functionalisation and ultrathin architectures maximise flux. Recent development of scalable fabrication methods for nanometre‐thick films, together with computational design tools, is accelerating the discovery of membranes tailored for carbon capture, hydrogen recovery, natural gas upgrading and air separation. Global efforts continue to refine resistance to plasticisation, ensure long‐term stability under mixed‐gas and humid conditions, and translate laboratory prototypes into robust modules for industrial deployment.

Research from Nature Portfolio

Recent studies have demonstrated that two‐dimensional MXene nanosheets can be assembled into perfectly aligned lamellar membranes exhibiting subnanometre channels, achieving exceptionally high hydrogen permeability alongside strong H2/CO2 selectivity. Another line of work has introduced a gel–vapour deposition route to produce ultrathin MOF membranes with controllable thickness down to tens of nanometres, yielding gas permeances orders of magnitude higher than conventional membranes while retaining high molecular sieving performance in H2, CO2 and C3 hydrocarbon separations. In parallel, the design of sub‐20 nm graphene oxide‐based hollow fibre membranes grafted with CO2-phillic brushes has realised outstanding CO2/N2 selectivity under wet flue‐gas conditions, underscoring the potential of facile coating methods and functional agents to combine ultrathin geometry with carrier‐mediated separation.

Research from all publishers

An integrative review of penetrant-induced plasticisation in microporous polymer membranes has elucidated the fundamental mechanisms by correlating polymer structure with pressure-dependent swelling, and has proposed targeted synthetic strategies to mitigate performance loss under mixed-gas environments. In parallel, hydrogen-bonded organic framework-based mixed-matrix membranes have been engineered via controlled nanoparticle assembly, achieving CO2 permeabilities near 800 Barrer and CO2/CH4 and CO2/N2 selectivities that exceed established upper bounds. Complementing experimental efforts, machine-learning approaches trained on existing polymer permeability data have predicted and guided the synthesis of novel membrane polymers that surpass traditional performance limits for key gas pairs, illustrating a powerful data-driven route to accelerate membrane discovery.

Membrane Gas Separation Technologies publication trend

The graph below shows the total number of articles in membrane gas separation technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Permeability: Measure of gas flux through a membrane per unit pressure difference, reflecting throughput capacity.

Selectivity: Ratio of permeabilities for two gas species, indicating the membrane’s discrimination power.

Mixed‐matrix membrane: Composite structure combining a polymer matrix with inorganic or organic porous fillers to enhance separation properties.

Molecular sieving: Size‐exclusion mechanism by which pores of precise dimension selectively transmit smaller molecules and reject larger ones.

Metal–organic framework (MOF): Crystalline network of metal ions linked by organic ligands, featuring uniform, tailorable porosity for sorption and sieving.

Polymer of intrinsic microporosity (PIM): Rigid, contorted polymer with interconnected micropores that afford high free volume and gas permeability.

References

1. Penetrant-induced plasticization in microporous polymer membranes. Chemical Society Reviews (2024).
2. Engineering HOF-Based Mixed-Matrix Membranes for Efficient CO2 Separation. Nano-Micro Letters (2023).
3. MXene molecular sieving membranes for highly efficient gas separation. Nature Communications (2018).
4. Metal–organic framework based mixed matrix membranes: a solution for highly efficient CO 2 capture?. Chemical Society Reviews (2015).
5. Redefining the Robeson upper bounds for CO 2 /CH 4 and CO 2 /N 2 separations using a series of ultrapermeable benzotriptycene-based polymers of intrinsic microporosity. Energy & Environmental Science (2019).
6. Ultrathin metal–organic framework membrane production by gel–vapour deposition. Nature Communications (2017).
7. Designing exceptional gas-separation polymer membranes using machine learning. Science Advances (2020).
8. Ultrathin graphene oxide-based hollow fiber membranes with brush-like CO2-philic agent for highly efficient CO2 capture. Nature Communications (2017).