An atom-thick graphene membrane for industrial gas separation

July 17, 2018, Ecole Polytechnique Federale de Lausanne
A single-layer nanoporous graphene reinforced with a nanoporous carbon film for the separation of hydrogen from methane. Credit: K. V. Agrawal/EPFL

Chemical engineers at EPFL have demonstrated for the first time that an atom-thick graphene membrane can separate gas mixtures with a high-efficiency. The "ultimate" membrane is scalable, making it a breakthrough for industrial gas separation.

Separating mixed gases, such as air, into their individual components is a process with multiple industrial applications, including biogas production, air enrichment in metal working, removal of toxic gases from natural gas, and hydrogen recovery from ammonia plants and oil refineries.

Gas separation usually takes place with the use of synthetic membranes made from polymers (e.g. cellulose) or other materials. In recent years, research has turned to what many refer to as the "ultimate" membrane: a layer of graphene, a single atom in thickness, which has been now shown to be the thinnest molecular barrier and hence the most efficient membrane, offering excellent permeance combined with robustness and scalability.

However, progress with developing graphene has met with two "bottlenecks": First, a lack of methods for incorporating molecular-sized pores into the layer of graphene, and second, a lack of methods for actually manufacturing mechanically robust, crack- and tear-free, large-area membranes.

Now, in a breakthrough that solves both problems, the team of Kumar Varoon Agrawal at EPFL Valais Wallis has developed a large-area, single-layer graphene membrane that can separate hydrogen from methane with a high-efficiency (separation factor up to 25), and an unprecedented hydrogen permeance from a porosity that was only 0.025%.

The membrane contains nanopores to allow hydrogen to permeate through, for what is known as "gas-sieving". The was stable at industrial pressures and temperatures (at least up to 7 bar and 250 ºC). But more importantly, the team was able to produce a surface are of 1 square millimeter – significantly larger than previous reports, where only a few square micrometers could be synthesized without cracks. Agrawal's group is now working to incorporate higher density of nanopores in graphene, to make graphene realize its true potential.

"The novel technique to produce crack-free graphene layer will go a long-way in realizing the ultimate performance of the atom-thick membranes for a number of important chemical separations including carbon capture, recovery and the purification of ," says Agrawal.

Explore further: Graphene makes its mark on gas separation

More information: Shiqi Huang et al. Single-layer graphene membranes by crack-free transfer for gas mixture separation, Nature Communications (2018). DOI: 10.1038/s41467-018-04904-3

Related Stories

Graphene makes its mark on gas separation

June 15, 2018

Graphene Flagship researchers overcame the theoretical limiting performance of membranes in gas separation. This collaborative research from Graphene Flagship partners CNR, University of Bologna and Graphene-XT has potential ...

Scientists produce dialysis membrane made from graphene

June 29, 2017

Dialysis, in the most general sense, is the process by which molecules filter out of one solution, by diffusing through a membrane, into a more dilute solution. Outside of hemodialysis, which removes waste from blood, scientists ...

Laying down a discerning membrane

October 4, 2013

One of the thinnest membranes ever made is also highly discriminating when it comes to the molecules going through it. Engineers at the University of South Carolina have constructed a graphene oxide membrane less than 2 nanometers ...

New insights on graphene

December 21, 2017

Graphene floating on water does not repel water, as many researchers believe, but rather attracts it. This has been demonstrated by chemists Liubov Belyaeva and Pauline van Deursen and their supervisor Grégory F. Schneider. ...

Recommended for you

Researchers engineer a tougher fiber

February 22, 2019

North Carolina State University researchers have developed a fiber that combines the elasticity of rubber with the strength of a metal, resulting in a tougher material that could be incorporated into soft robotics, packaging ...

A quantum magnet with a topological twist

February 22, 2019

Taking their name from an intricate Japanese basket pattern, kagome magnets are thought to have electronic properties that could be valuable for future quantum devices and applications. Theories predict that some electrons ...

Solving the jet/cocoon riddle of a gravitational wave event

February 22, 2019

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.