[Image above] Credit: halfrain; Flickr CC BY-SA 2.0
Remember that CTT story from last summer about the nanoporous carbon–nitrogen and carbon–sulfur materials that could remove CO2 from natural gas wellheads? The material, developed in James Tour’s Rice University lab, now has a better and cheaper competitor—asphalt.
Tour’s lab now says they have outdone their own work and have developed a derivative of asphalt—asphalt-porous carbon (A-PC)—that can soak up 114% of its weight in CO2 and is much cheaper than any alternative.
“This provides an ultra-inexpensive route to a high-value material for the capture of carbon dioxide from natural gas streams,” Tour says in a Rice University press release. “Not only did we increase its capacity, we lowered the price substantially.”
The new material, like the one I talked about last summer, grabs CO2 under pressure provided by the rising gas itself. The material also reversibly releases the gas when pressure is removed, allowing CO2 to be pumped downhole or collected for other uses. It can play this CO2 catch-and-release game over and over again without degrading, the team reports, making an already cheap material incredibly cost-effective.
To make the material, the team mixed A-PC with KOH at >600°C and nitrogen-doped and hydrogen-reduced the product to get a porous material with a lot of surface area—2,780 m2/g, the team reports in an Applied Material and Interfaces paper.
According to the press release, current materials used for carbon capture only nab ~13% CO2 by weight and are much more expensive, making the new asphalt-based material very attractive for both cost and efficiency.
The paper is “Asphalt-derived high surface area activated porous carbons for carbon dioxide capture” (DOI: 10.1021/am508858x).