Process speeds up conversion of natural gas
8 May 2013
Chemical engineers have identified a new mechanism to convert natural gas into energy up to 70 times faster.
This could make power generation from natural gas both cleaner and more efficient,” said Fanxing Li, assistant professor of chemical and biomolecular engineering at North Carolina State University.
At issue is a process called chemical looping, in which a solid, oxygen-laden material- called an “oxygen carrier”- is put in contact with natural gas.
The oxygen atoms in the oxygen carrier interact with the natural gas, causing combustion that produces energy.
Improving this process hopefully moves us closer to commercial applications
Previous state-of-the-art oxygen carriers were made from a composite of inert ceramic material and metal oxides.
But Li’s team has developed a new type of oxygen carrier that include a “mixed ionic-electronic conductor,” which effectively shuttles oxygen atoms into the natural gas very efficiently.
According to the researchers, this makes the chemical looping combustion process as much as 70 times faster.
The mixed conductor material is held in a nanoscale matrix with an iron oxide, otherwise known as rust.
The rust serves as a source of oxygen for the mixed conductor to shuttle out into the natural gas.
In addition to energy, the combustion process produces water vapor and CO2.
By condensing out the water vapour, researchers were able to create a stream of concentrated CO2 to be capture for sequestration.
“Improving this process hopefully moves us closer to commercial applications that use chemical looping, which would help us limit greenhouse gas emissions,” said Li.
