Molecular sieve pulls CO2 from the air

Posted by Kate Taylor

Scientists at the University of Melbourne have developed a new way of capturing carbon dioxide that should reduce the cost of separating and storing the gas.

Quite apart from carbon capture as a way of countering global warming, pure CO2 is useful to industry. But current processes are pretty inefficient, needing several stages of refining and extraction before a pure form of the gas is produced.

The team's new method is based on a molecular sieve, an ultra-fine filter system.

"Because the process allows only carbon dioxide molecules to be captured, it will reduce the cost and energy required for separating carbon dioxide," says Professor Paul Webley.

"The technology works on the principle of the material acting like a trap-door that only allows certain molecules to enter.Once entered, the trapdoor closes and the carbon dioxide molecules remain."

“We took a collaborative approach to this research with input from CSIRO, the Department of Materials Engineering and Mechanical Engineering at Monash University and the Australian Synchrotron.

The new technique could be used to separate carbon dioxide from sources such as power stations and natural gas sources.

"Many natural gas fields contain excess carbon dioxide that must be removed before the gas can be liquefied and shipped," says Webley. "While we can’t change industry in a hurry, we have provided a viable bridging solution."