Carbon Dioxide is a growing concern due to how it impacts global climate. CO2 is formed when carbon binds with oxygen at power plants used to generate electricity. Scientists at DOE’s National Energy Technology Laboratory are in the process of developing a way to separate the elements and capture them for permanent disposal.
The capture process will not create new waste, it is quick and efficient, and the CO2 can be used as high-pressure gas that can be transported in a pipeline to be injected somewhere else.
Researchers at NETL are using chemicals called sorbents to absorb carbon dioxide after it is generated from power plants. These sorbents react with CO2 to create solid materials. Once it is separated, the solid is then broken down into CO2 gas and the original sorbent chemical is reused to capture more CO2. Researchers use good sorbents and the right conditions to get maximum results.
Since there are millions of possible solid materials that could act as sorbents, researchers at NETL have devised a way to find the good ones. Using a combination of computer modeling and experiments, they can identify and test sorbents that will work in a power plant environment. These computer programs have the ability to sort through quite a bit of thermodynamic data on materials reacting with carbon dioxide to find the right ones. They explored a series of lithium silicates with Li2O/SiO2 ratios and found that when adding SiO2 to decrease the ratio, this generated more favorable results at power plants.
Researchers at NETL also found a magnesium hydroxide sorbent that works for carbon dioxide capture. The process can work at a higher pressure, and takes significantly less energy to compress and use for pipeline transport. A U.S. patent has been issued on the process.