News Ticker

Carbon sponge could capture and store coal emissions, say researchers

Could a carbon sponge soak up coal emissions? Scientists from Monash University and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) believe it is possible.

They contend that emissions from coal power stations could be significantly reduced by a novel material that absorbs massive amounts of carbon dioxide, then releases it when exposed to sunlight. They found a class of materials known for their special ability to store gases. This has helped them develop a new means of capturing and storing carbon dioxide.

According to the World Coal Association, coal-fired power plants fuel 41 percent of global electricity (IEA 2011 figures). In some countries, like South Africa, China and Poland, coal fuels a higher percentage of electricity. Scientists have been hard at work for decades trying to come up with ways to reduce coal emissions.

The carbon sponge overcomes many of the issues associated with current methods of carbon capture by using sunlight to release the stored carbon. According to a Monash University news release, current carbon capture technologies use liquid capture materials that are then heated to release the built up carbon dioxide.

Bradley Ladewig of the Monash Department of Chemical Engineering cheered the photosensitive metal organic framework (MOF) as a significant advancement in emissions reduction technology. This class of materials gives scientists the ability to create carbon capture system systems that utilize sunlight to set in motion the release of carbon dioxide, he said.

MOFs are groups of metal atoms linked by organic molecules. Their extremely high internal surface area allows them to store large volumes of gas.

This MOF was created using light-sensitive azobenzene molecules, according to Monash University PhD student and lead author Richelle Lyndon. She said that the MOF can release the absorbed carbon dioxide just like a sponge releases water when squeezed.

Although the MOF that scientists found had a particular attraction to carbon dioxide, the light responsive molecules could potentially be used with other MOFs, allowing the new emissions reduction technology to work with other gases.

Researchers are busy trying to “optimize” the MOF to augment the efficiency of carbon dioxide to levels that match an industrial environment.

According to the EPA, carbon dioxide is the primary greenhouse gas emitted through human activities. In 2010, for example, carbon dioxide accounted for approximately 84 percent of all U.S. gas emissions from human activities. The EPA notes that human activities are changing the carbon cycle by adding more carbon dioxide to the atmosphere and by impacting the ability of natural sponges, like forests, to remove carbon dioxide from the atmosphere.

The EPA notes that the federal government is conducting a number of carbon dioxide capture and sequestration-related activities including sharing technological know-how. To learn more about available and emerging emissions reduction technologies read the EPA’s paper on the subject here.

The study’s findings were described in detail in the journal Angewandte Chemie.