Green Technology Forum

Approximately one third of the total carbon dioxide (CO2) emissions in the world come from energy production. CO2 free gas-powered plants are based on carbon dioxide being removed from the waste gases and deposited in the ground.

However, before CO2 can be stored, it must be separated from the waste gases. The current methods used for this type of filtration are expensive and require the use of chemicals. A new membrane technology is going to change that.

This new type of membrane has been internationally patented by researchers at The Norwegian University of Science and Technology (NTNU) in Trondheim. The membrane is made from a plastic material that has been structured by means of nano technology. It catches CO2 while other waste gases pass freely.

Eco-friendly technology

According to the scientists, the technology is effective, inexpensive and eco-friendly, and can be used for practically all types of CO2 removal from other gases. Its effectiveness increases proportionally to the concentration of CO2 in the gas.

This method, known as facilitated transport, is comparable to the way human lungs get rid of CO2 when we breathe: it is both a complex and an effective mechanism.

“The novelty is that instead of using a filter that separates directly between CO2 and other molecules, we use a so-called agent. It is a fixed carrier in the membrane that helps to convert the gas we want to remove,” says NTNU professor May-Britt Hägg. She is head of the research group Memfo that works on the new membrane technology.

The agent helps so that the CO2 molecules in combination with moisture form the chemical bicarbonate, which is then quickly transported through the membrane. In this manner, the CO2 is released while the other gases are retained by the membrane.

Various materials are used to make membranes, including plastic, carbon and/or ceramics.

Membrane separation of gases is a highly complex process. The materials must be tailored in an advanced way to be adapted to separate specific gases. They must be long-lasting and stable.

Nanotechnology

The new membrane is made of plastic, structured by means of nanotechnology to function according to the intention. Membranes based on nano-structured materials are eco-friendly and will reduce the costs of CO2 capture.

“With this method, we can remove more CO2 and obtain a cleaner product for smaller plants. Thus, it becomes less expensive,” Hägg says.

source: engineerlive.com

This entry was posted on Tuesday, February 12th, 2008 at 7:45 am and is filed under Environment, Materials, Nanotechnology, News, Research. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.