A new relevant membrane application: CO2 direct air capture (DAC).

[Display omitted] • Membranes as a promising tool for CO 2 capture. • A perspective on direct air capture (DAC) from atmosphere is given. • Process considerations to make DAC feasible are addressed. • Advantages and drawbacks of membranes over other DAC technologies are provided. • An outlook of DAC using membranes is elucidated. Since carbon dioxide (CO 2) is the primary greenhouse gas emitted into the atmosphere due to human activities, strong research efforts have been developed towards capturing and decreasing its production. Unfortunately, specific processes and activities make it impossible to avoid CO 2 emissions. Among the different strategies scientists propose for CO 2 reduction, direct CO 2 capture from the atmosphere, also known as direct air capture (DAC), represents a promising alternative in which sorbents have been mainly used. Recently, gas separation membranes have also been speculated to carry out such a separation, thanks to their smaller footprint and simpler setup and operation; however, their application remains a proposition in the field. This paper gives a perspective of the ongoing research and attempts of DAC applications via membrane separation and introduces the main membrane materials and types used for CO 2 separation. Finally, the process considerations for DAC using membranes are stated to guide the new researchers in the field. [ABSTRACT FROM AUTHOR]