Update: here's an interview with the professor who conducted this interesting research.

Researchers from the University of Colorado Boulder demonstrated that graphene membranes with tiny pores can effectively and efficiently separate gas molecules through size-selective sieving. Such membranes could one day be used to make natural gas production more efficient, and reduce CO2 emissions from power plant exhaust pipes.

The researchers used ultraviolet light-induced oxidative "etching" to introduce nanoscale pores in graphene sheets. They measured permeability of various gases across the membranes. The membrane can be used to separate gases based on molecular size. Graphene is an ideal material for separation membranes because it's durable but does not require a lot of energy to push molecules through it.