When it comes to fixing climate change, most people focus on the idea that we need to stop putting carbon dioxide into the atmosphere. But what if we could also take it out?
Many scientists are working on carbon sequestration, the process of capturing and storing carbon dioxide for long periods of time. Carbon sequestration from the smokestacks of power plants is an idea that’s been around for awhile, but isn’t widely used–largely because the process uses up nearly a third of the energy produced by a power plant in the first place.
But researchers at University of California-Berkeley have developed a new material that they believe will make carbon capture and sequestration a competitive and viable mechanism for reducing emissions. The material is a metal-organic framework, or MOF, that is a composite of magnesium or manganese with nitrogen compounds called diamines. Because the material is a solid and not a liquid (which is normally used and must be transported and heated), it requires less energy in the process.
“This material is unique in that it binds CO2 in a cooperative mechanism,” says Jeffrey Long, a UC Berkeley professor of chemistry. “When the first CO2 starts to adsorb at a very specific pressure, all of a sudden it facilitates more CO2 adsorption, and the MOF rapidly saturates.”
At a chemical level, the process is similar to how plants absorb carbon dioxide, Long and his team explained in a paper in the academic journal Nature. The end result is that these MOFs can absorb and release carbon for half the energy cost of current carbon-capturing materials. According to Long, the MOFs would be installed as a giant filter in the flue stack of power plants, like a filter on a cigarette at a much larger scale.
“They would be implemented most simply in large columns that the flue gas would flow through prior to release up the flue stack,” says Long. “With these new materials, the carbon-capture unit could be much smaller, making the capital costs drop tremendously as well as the operating costs.”