A study co-authored by two UC Berkeley professors resulted in the creation of a new material that can capture carbon dioxide from wet flue gases in an effort to mitigate climate change.
The material in this study was designed for the purpose of capturing carbon dioxide from the exhaust of power plants, according to Jeffrey Reimer, professor and chair of UC Berkeley’s chemical and biomolecular engineering department.
“It is this nice closed loop,” Reimer said, describing the study. “Societal problem, design something on a computer, create something the computer designed and implement it, it works, and the reason it worked is because on a molecular scale, it performed exactly how the computer said it would perform.”
The researchers used a computer to design a material, and in their search with the computer, they constrained the computer to search for or create “metal organic frameworks,” or MOFs. Reimer described MOFs as “tinker toys,” a construction toy consisting of a wooden spool with divots and sticks placed in those divots.
The hub, or spool, of the MOF is a metal, and the sticks are organic material. In creating the material on the computer, Reimer said the most common type of MOF was one where the hub was made of aluminum and the sticks were like “mothballs.”
“When you look at a picture of this metal organic framework (the computer created), what you see in the node, the part where the holes are aluminum with some oxygen and the sticks are actually molecular rings fused together that spans the space between the spacers,” Reimer added.
The purpose of this material is to extract carbon dioxide from wet flue gases.
Flue gases are essentially exhaust gases, and the word “wet” is included because, during combustion, carbon dioxide and water are produced, according to Reimer. The gas from power plants is wet with water. The material created in this study separates this water with the fused rings, which attract carbon dioxide and repel water.
To use the material, Reimer said, the powder is coated or painted onto a ceramic device shaped “like a honeycomb,” and the “gas can easily pass through the honeycomb and has plenty of a chance to interact with the surface.”
Reimer added that his team is trying to utilize the material by creating “pellets” almost like “cat litter,” so the wet flue gas can easily pass around and come into contact with the pellet.
“What is important about this study is that scientists around the world are working on schemes to get carbon out of the air, to mitigate climate change,” Reimer said. “That is one thing you get out of the study.”