Researchers have developed a new material containing common glue molecules which may help tackle climate crisis by capturing the greenhouse gas carbon dioxide (CO2) directly from the air. Carbon capture materials are a crucial part of a range of technologies, alongside renewables and energy efficiency solutions, that can help reduce the amount of CO2 we release into the atmosphere, according to the research published in the journal Chemistry of Materials.
"We show that small epoxy molecules typically found in glues can stick larger ones together to make effective carbon capture materials potentially useful to tackle climate change," said Enrico Andreoli, from Swansea University in the UK. "We've developed a new approach to making an effective CO2 capture material from a widely studied CO2-reactive polyamine by reaction with an industrially mass-produced epoxy resin," Louise Hamdy, first author of the research paper, added.
"This material shows very high CO2 uptake and could potentially be used to capture CO2 from industrial flue gas streams or from the air, relieving us from some of the worst effects of global warming," Hamdy said.
Current CO2 capture technologies need to be significantly advanced. Major challenges include materials cost, capacity, CO2-selectivity, regeneration, robustness and stability to water.
Solid CO2 capture materials composed of polyamines supported on alumina or silica have emerged as promising carbon capture materials.
The researchers cross-linked the polyamine into a solid by using epoxy resin -- constituting just one-tenth of the mass of the material --maximising the CO2-reactive component and avoiding the use of a support.
"This confirms the validity of my original idea of using cross-linking as an alternative to bulky supports," said Andreoli.
The cross-linked material modified with a hydrophobic additive captured almost 20 per cent of its weight in pure CO2 at 90 degrees Celsius, researchers said.
This finding confirmed a previous hypothesis that the introduction hydrophobic groups can disrupt the internal structure of the material to promote CO2 uptake by the polyamine, they said.
The additive not only increased the amount of captured CO2 but did so at a lower temperature.
"This finding is significant as it proves that through the introduction of additives, we can fine tune these materials for optimum performance at specific working temperatures," Hamdy said.
Experiments revealed the functionalised sample to be highly selective for CO2 over nitrogen (N2), showing negligible uptake of N2.
Selectivity was further explored by testing the material performance under flue gas-like conditions.
This revealed that the sample could capture 9.5 per cent of its weight in CO2 under a dilute CO2 stream of 10 per cent CO2/90 per cent N2 at 90 degrees Celsius in only 15 minutes.
The functionalised material also performed exceptionally well under humid conditions -- often a huge challenge for many CO2 sorbent solids.
At 25 degrees, in pure CO2, the pre-hydrated material was able to capture an impressive 23.5 per cent, researchers said.
This opens up the possibility of this material being developed for capture of CO2 directly from the air, they said.