Metal-organic material set to boost efficiency of carbon capture

US and Saudi researchers say material will improve clean coal and carbon capture plants

Researchers in the US and Saudi Arabia have developed a metal-organic material which can be used for more efficient and cheaper CO2 capture and separation. 

The research, conducted at the University of South Florida and the King Abdullah University of Science and Technology, was published this month in the journal Nature. It shows that SIFSIX-1-Cu can be used in both pre- and post-combustion CO2 separation as well as natural gas clean-up, enabling the performance of clean-coal and carbon capture and storage plants to be significantly improved.

Metal-organics are used in the manufacture of some semiconductors and are also being developed for use in hydrogen storage applications. SIFSIX-1-Cu is a crystal whose atoms form a three-dimensional lattice with holes that “snare” molecules of CO2, but allow other molecules to pass through. The research team successfully built the porous SIFSIX material using combinations of inorganic and organic chemicals and then used computer simulations to show how the CO2 gas molecules would interact with it.

According to Mike Zaworotko, Professor of Chemistry at the University of South Florida, the material’s main improvement is that it is highly effective in the presence of water vapour, a standard that other materials have not been able to meet. Water normally interferes with CO2 capture, but SIFSIX-1-Cu resists it, making it a promising candidate for real world applications.

Zaworotko, said: “I hate to use the word unprecedented, but we have something unprecedented. We’ve sort of hit a sweet spot in terms of properties.”

One of the biggest challenges of capturing CO2 before it enters the atmosphere is the energy costs associated with its separation and purification. Researchers at the University of South Florida estimate that the separation and purification of CO2 on an industrial scale consumes around 15% of global energy production, and note that the amount of CO2 being captured globally is expected to triple by 2050.

SIFSIX-1-Cu is an adaptation of a material created more than 15 years ago and is named after the chemical component that leads to its special properties. Its chemical name is hexafluorosilicate.