Columbia Engineers Develop New, Low-Cost Way to Capture Carbon

[OKIsItJustMe]

http://engineering.columbia.edu/columbia-engineers-develop-new-low-cost-way-capture-carbon

[font face=Serif][font size=5]Columbia Engineers Develop New, Low-Cost Way to Capture Carbon[/font]

Jun. 23, 2016

[font size=3]A recent study led by Xi Chen, associate professor of earth and environmental engineering at Columbia Engineering, and Klaus Lackner at Arizona State University, reports an unconventional reversible chemical reaction in a confined nanoenvironment. The discovery, a milestone in clarifying the scientific underpinnings of moisture-swing chemical reaction, is critical to understanding how to scrub CO₂ from the Earth's atmosphere, and the researchers have already used it to capture CO₂ more efficiently and at a much lower cost than other methods.

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Reaction pathway of CO₂ absorbption/desorption on nanostructural absorbent[/font][/center]
Water is the key player in this new study. The group found that reducing water quantities in nanoconfinement could promote CO₃²^- (carbonate) ions to hydrolyze H₂O into a larger amount of OH^- (hydroxide) ions. This discovery also led the team to find a new nanostructured CO₂ sorbent (a material used to absorb or adsorb liquids or gases) that also binds CO₂ spontaneously in ambient air when the surrounding is dry, while releasing it when exposed to moisture. The work was published in Angewandte Chemie in February 2016.

“Water confined in nanoscopic pores is essential in determining the energetics of many chemical, physical, biological, and environmental systems,” says Chen. “Our finding sheds light on a vast number of chemical processes in nanoconfinement while also giving rise to a wide array of potential applications. For instance, we can convert this new efficient sorbent from absorption to desorption simply by using water, which is readily available and at very low-cost. Current sorbent materials consume a great deal of energy, so our discovery could lead to cheaper and more efficient energy conservation absorbents. And if we can achieve negative carbon emission standards, then we will have invented a nanomaterial solution to a critical global challenge.”

Finding an efficient absorbent has long been a challenge for most absorption and desorption processes. A successful CO₂ absorbent must have fast reaction kinetics (the rate of chemical processes), be low in cost, and be able to regenerate with a low energy barrier to complete the whole CO₂ capture-release cycle. Chen notes that, to his knowledge, all previous CO₂ absorbents have required a large energy barrier to regenerate and are thus not very efficient, consuming more extra energy to regenerate. The mechanism of the moisture-swing chemical reaction in nanopores will lead to new classes of sorbents driven by water: evaporation in ambient air through solar energy drives the sorbent to absorb CO₂ as it dries, and hydration releases CO₂ when wet.

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[tonyt53]

1. Good stuff!