Fastest Carbon Dioxide Catcher Heralds a New Era for Direct Air Capture – Is It Up With That?
The new carbon absorber is 99% efficient, lightning fast and easily recyclable
TOKYO METROPOLITAN UNIVERSITY
Tokyo, Japan – Researchers from Tokyo Metropolitan University have developed a new carbon capture system that removes carbon dioxide directly from the atmosphere with unprecedented efficiency. Isophorone diamine (IPDA) in the “liquid-solid phase separation” system was found to remove carbon dioxide at low concentrations from the atmosphere with 99% efficiency. The compound is reusable with minimal heating and is at least twice as fast as existing systems, an exciting new development for direct gas capture.
The devastating effects of climate change are being felt around the world, with an urgent need for new policies, lifestyles and technologies that will lead to a reduction in carbon (sic) emissions. However, many scientists are looking beyond the net-zero emissions goal, toward a “beyond-zero” future where we can actively reduce the amount of carbon dioxide in the atmosphere. The field of carbon capture, removal and subsequent storage or conversion of carbon dioxide, is growing rapidly, but hurdles remain before it can be deployed on a large scale.
The biggest challenges come from efficiency, especially in handling direct atmospheric air in so-called direct air capture (DAC) systems. The concentration of carbon dioxide is such that the chemical reaction with the absorbent is very slow. There is also the difficulty of releasing carbon dioxide back into more sustainable capture and desorption cycles, which in itself can be very energy intensive. Even leading efforts to build DAC plants, such as those using potassium hydroxide and calcium hydroxide, run into serious problems with efficiency and recovery costs, prompting the hunt new processes become imperative.
A research team led by Professor Seiji Yamazoe of Tokyo Metropolitan University has been working on a type of DAC technology known as a liquid-solid phase separation system. Many DAC systems involve bubbling gas through a liquid, with a chemical reaction occurring between the liquid and carbon dioxide. As the reaction continues, more reaction products accumulate in the liquid; this makes subsequent reactions slower and slower. The liquid-solid phase separation system offers an elegant solution in which the reaction product is insoluble and exits the solution as a solid. There is no accumulation of product in the liquid, and the reaction rate is not slowed down much.
The team focused their attention on liquid amine compounds, modifying their structures to optimize reaction rates and efficiency with a wide range of carbon dioxide concentrations in the air, from about 400ppm to 30%. They found that an aqueous solution of one of these compounds, isophorone diamine (IPDA), was able to convert 99% of the carbon dioxide present in the air into a solid carbamic acid precipitate. Importantly, they demonstrated that solids dispersed in solution only need to be heated to 60 degrees Celsius to completely release the captured carbon dioxide, recovering the original liquid. The carbon dioxide removal rate is at least twice as fast as leading lab DAC systems, making it the fastest carbon dioxide capture system in the world today for low concentrations of carbon dioxide in air (400ppm).
The team’s new technology promises unprecedented performance and robustness in DAC systems, with broad implications for large-scale deployed carbon capture systems. In addition to improving their systems further, their vision of a “zero-zero” world now focuses on how the captured carbon can be effectively used, in industrial applications and household products. .
This work was supported by Project No. P14004 of the New Energy and Industrial Technology Development Organization (NEDO).
JOURNEYS
ACS Environment Au
DOI
10.1021 / acsenvironau.1c00065
ARTICLE TITLE
Direct CO2 capture using a solid carbamic acid-liquid carbamic acid phase separation system using Aminocyclohexyl group-carrying diamides
ARTICLE PUBLICATION DATE
May 10, 2022
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