Researchers at Tokyo Metropolitan University have created what they say is the fastest carbon dioxide catcher ever, possibly heralding a new era in the fight against carbon emissions linked to climate change.
The new carbon capture system is said to remove carbon dioxide directly from the atmosphere “with unprecedented performance”, with experts saying that they want to not only slow down climate change but also go “beyond zero” and actually reduce the amount of carbon dioxide in the atmosphere.
The expert said that the isophorone diamine (IPDA) in a “liquid-solid phase separation” system was “found to remove carbon dioxide at the low concentrations contained in the atmosphere with 99-percent efficiency.”
They said that it was at least as twice as fast as existing systems and that it uses compounds that are reusable, labelling it an “exciting new development for direct air capture”.
The Tokyo Metropolitan University said in a statement: “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 reduced carbon emissions.
“However, many scientists are looking further ahead than a net-zero emission goal, to a future ‘beyond zero’ where we can actively reduce the amount of carbon dioxide in the atmosphere.
“The field of carbon capture, the removal and subsequent storage or conversion of carbon dioxide, is developing rapidly, but hurdles remain before it can be deployed at scale.”
They said that the biggest challenge is currently efficiency, because there are such high concentrations of carbon dioxide in the atmosphere that absorbing them can be quite slow.
This in turn makes the “hunt for new processes notably urgent”.
The team that developed this new system was led by Professor Seiji Yamazoe of Tokyo Metropolitan University and they have been studying a direct air capture (DAC) technology known as liquid-solid phase separation.
The university said in its statement: “Many DAC systems involve bubbling air through a liquid, with a chemical reaction occurring between the liquid and the carbon dioxide. As the reaction proceeds, more of the reaction product accumulates in the liquid; this makes subsequent reactions slower and slower.”
In the last few years, researchers, for example, discovered that some solid, often metal, catalysts could convert CO2 into solid carbon. But these often only work at high temperatures, and providing that heat requires a lot of energy and money. Furthermore, carbon particles accumulate in the heated liquid, eventually slowing down the process.
But the university added that the researchers may have found a solution, saying: “Liquid-solid phase separation systems offer an elegant solution, where the reaction product is insoluble and comes out of solution as a solid.
“There is no accumulation of product in the liquid, and the reaction speed does not slow down much.”
The team focused on liquid amine compounds and modified their structures so as to optimise their reaction speed and efficiency when dealing with various concentrations of carbon dioxide in the air.
They were able to improve one of these compounds, isophorone diamine (IPDA) and found that it could convert 99 per cent of the carbon dioxide in the air into a solid.
The university said: “Crucially, they demonstrated that the solid dispersed in solution only required heating to 60 degrees Celsius to completely release the captured carbon dioxide, recovering the original liquid.”
The university added: “The rate at which carbon dioxide could be removed was at least twice as fast as that of the leading DAC lab systems, making it the fastest carbon dioxide capture system in the world at present for processing low concentration carbon dioxide in air (400ppm).”
The next part of their research is focused on how to use this new system effectively and how to scale it up, whether this will be in industrial applications or in household products.
The team’s peer-reviewed research has been published in the academic journal ACS Environmental. As well as Professor Yamazoe, the study, titled ‘Direct Air Capture of CO2 Using a Liquid Amine–Solid Carbamic Acid Phase-Separation System Using Diamines Bearing an Aminocyclohexyl Group’, was also authored by Soichi Kikkawa, Kazushi Amamoto, Yu Fujiki, Jun Hirayama, Gen Kato, Hiroki Miura, and Tetsuya Shishido.