Low-cost material for direct air capture of CO2

Researchers at Monash University have developed a group of low-cost solid materials that show great promise for use in systems to capture excess carbon dioxide directly from the atmosphere.

The study, entitled Amine-functionalized meso-macroporous polymers for efficient CO₂ capture from ambient air, was published in ACS Applied Materials & Interfaces.

Known as “meso-macroporous melamine formaldehyde (MF)”, the new materials can be made relatively easily from the common and low-cost chemicals melamine and formaldehyde and have extra-large pores to facilitate direct air capture (DAC) of carbon dioxide.

Until now, large-scale deployment of DAC as a negative carbon emission technology has been slow due to the low performance and high cost of solid materials capable of capturing significant amounts of carbon dioxide at low levels present in ambient air and at normal temperatures.

Co-lead researcher Professor Paul Webley said: “We believe these MF materials represent a significant advance towards commercialisation of DAC processes. The ultrahigh pore volume and the meso-macroporous structure makes MF a superior base for making DAC adsorbent materials.”

MF can be formed into droplets, pellets and coatings and can be easily impregnated with tetraethylenepentamine (TEPA), a proven adsorbent for carbon dioxide removal.

Molecular groups known as amines, which contain nitrogen atoms bonded to hydrogen atoms, have a strong ability to form chemical bonds with carbon dioxide and capture it from gas mixtures, even at low concentrations.

(Note: Although CO₂ levels have risen rapidly since the onset of the industrial revolution, from around 280 to 415 ppm, CO₂ accounts for a very low proportion of the earth’s atmosphere.)

“Our results demonstrate the great potential of amine-impregnated MF adsorbents for carbon capture, paving the way for the development of advanced DAC systems,” Webley said.

Image credit: iStock.com/Dmitry Kovalchuk