New uses for copper in a climate-change world

hqdefault_1.jpg

Copper could become a crucial ingredient in reducing fossil fuel emissions, with new research showing the element improves the efficiency of chemical looping.

The US Department of Energy’s National Energy Technology Laboratory (NETL) has carried out tests which showed that copper helps to economically remove carbon dioxide emissions from coal-fired power generation.

Chemical looping involves combusting the fuel in question, coal, with an oxygen carrier like iron oxide, which is later re-oxygenated for use in the cycle again.

The process produces carbon dioxide in a pure exhaust stream which can be easily captured for other industrial uses or sequestration.

NETL research scientist Dr Ranjani Siriwardane said that preliminary testing of a new, copper based oxygen carrier has demonstrated good methane conversion, circulation and heat management.

Copper has not previously been used for chemical looping due to its low melting point, however the discovery was made in testing a mixed metal oxygen carrier which used iron oxide and a concentration of copper oxide for high reactivity and ability to withstand high temperatures.

Siriwardane said tests were conducted in a pilot scale chemical looping combustor unit at NETL.

“We conducted the tests at around 800 and 900°C,” she said. 

“What we found was the design we developed can function in a chemical looping reactor more efficiently than traditional oxygen carriers.

“It takes us closer to the possibility of deploying chemical looping on a large scale as a less expensive way to reduce CO2 emissions.”

A patent application has been made on the technology in preparation for testing on a commercial scale.