Tokyo Metropolitan University researchers have developed a new way to capture carbon emissions. The technology, using isophorone diamine (IPDA) in a “liquid-solid phase separation” system, can remove carbon dioxide from the atmosphere with 99% efficiency.
According to the research team, the compound is reusable, requires little heating, and is at least twice as quick as existing devices, making it an exciting invention for direct air capture (DAC).
Climate change is causing devastating influence all around the world, and there is an urgent need for new policies, lifestyles, and technology that will reduce carbon emissions.
Many scientists are looking beyond a net-zero emission target, seeking to reduce the amount of carbon dioxide in the atmosphere. The field of carbon capture, or the removal and subsequent storage or conversion of carbon dioxide, is fast evolving, but challenges remain before it can be applied at large scale.
The most difficult challenges are related to efficiency, particularly when processing atmospheric air directly in DAC systems. Chemical reactions with sorbents become sluggish when carbon dioxide concentrations become higher.
There is also the challenge of removing the carbon dioxide in more sustainable capture-and-desorption cycles, which can be quite energy intensive. DAC facilities also have efficiency and recovery challenges, making the search for new technologies more important.
Many DAC systems involve bubbling air through a liquid, with a chemical reaction occurring between liquid and carbon dioxide. As the reaction proceeds, more of the reaction product accumulates in the liquid, and this slows the reactions.
To fix the problem, a team led by Professor Seiji Yamazoe of Tokyo Metropolitan University has been researching liquid-solid phase separation systems, a type of DAC technology. Under the system, reaction product is insoluble and comes out of solution as a solid. Since there is no product accumulation in the liquid, the reaction speed does not slow much.
The researchers focused on liquid amine compounds, changing their structure to enhance reaction speed and efficiency. They found that an aqueous solution of one of these compounds, isophorone diamine (IPDA), could convert 99% of the carbon dioxide in the air to a solid carbamic acid precipitate.
They also proved that heating the solid distributed in solution to 60 degrees Celsius was sufficient to entirely release the captured carbon dioxide and return the original liquid. The rate at which carbon dioxide could be removed was at least double that of the leading DAC lab systems.
The team’s innovative approach offers unprecedented performance and stability in DAC systems, with far-reaching implications for large-scale carbon capture systems.
