This Powder Could Cheaply Capture Carbon Pollution From Power Plants

By Marlene Cimons

A recent UN report found that to prevent catastrophic climate change, humans will not only need to drastically cut emissions in just a few short years. People will also need to generate power from wind and solar, and they will need to upgrade remaining gas- and coal-fired power plants with carbon capture technology—a means of trapping carbon pollution from power plants and storing it underground. But carbon capture has its drawbacks. The equipment is costly and the process requires a lot of energy.

Scientist Zhongwei Chen has developed an alternative, one that could make it more affordable for coal- and gas-fired power plants to clean up their mess.

Chen, a professor of chemical engineering at the University of Waterloo, created a powder that can soak up carbon dioxide before it is expelled into the air, which he said is vastly more efficient than conventional carbon capture methods. He said it can be used at power plants, factories and other facilities that burn coal. "This technology is designed to be a real solution to a real problem the world is facing right now," Chen said. "If this technology can help us do better while we find and adopt new, reliable energy sources, that's positive." His study describing the technique appears in the journal Carbon.

Carbon dioxide molecules stick to the surface of carbon when they come in contact with it, a process known as "adsorption," making carbon an excellent material for CO2 capture. The researchers, who collaborated with colleagues at several universities in China, enhanced adsorption by manipulating the size and concentration of pores in the carbon powder. The carbon spheres that make up the powder have many, many pores and the vast majority of them are less than one-millionth of a meter in diameter.

Like other carbon capture methods, the CO2-saturated powder still would need to be buried underground to ensure the carbon dioxide is not released into the atmosphere. But the powder represents a significant breakthrough. While there have been earlier experiments to try to develop "pore-forming" carbon dioxide agents, Chen calls the powder made by his team "the first viable attempt." With previous efforts, the mixtures were corrosive and not absorbent enough, he said.

Carbon dioxide molecules are gathered by the carbon spheres that make up Chen's powder. Carbon

"Our powder is efficient because it has pores that are two to three times larger than a carbon dioxide molecule," Chen said. "By ensuring we have the right number of pores in the right concentration, the powder is able to effectively scoop up the carbon from emissions as it passes through." The powder can be used without needing to install additional equipment. And the raw materials—sugar, molasses, rice husk, straws or agar—are renewable, abundant and cheap, especially when compared to existing technologies.

"One of the most important aspects of this discovery is that it's not expensive," said Chen, who holds a Tier 1 Canada research chair in advanced materials for clean energy, an appointment that recognizes academics who are outstanding in their field. "It can be employed by developed and developing nations alike. Since cost is not a barrier to taking action, we have the ability to see significant change in a very short time. There are not a lot of other solutions out there we can say that about."

Reposted with permission from our media associate Nexus Media.