CO2 capture with superbases

Direct and reversible, low energy cost CO₂ capture from air (direct air capture, DAC) is a major scientific and industrial challenge. It is needed for efficient and economically viable concepts to turn society and the chemical industry to carbon neutral or even carbon negative. It can be seen also a way to produce clean CO₂ for the chemical industry needed in the synthesis of many chemicals such as sustainable polar solvents, monomers or polymers, pharmaceutical compounds, and even fuels. To enable this wide range of applications, it is crucial to have a DAC process that can easily capture and release the trapped CO₂ with a low energy requirement, and in an economically and environmentally sustainable manner.

Hydroxide solvents are currently one of the most used processes for the direct capture of CO₂ from air. However, this technology requires high heat, up to 900°C, to recover the CO₂. Monoethanolamine is a widely used industrial process for capturing CO₂ from flue gasses. However, the corrosive nature of this amine and the high energy for the CO₂ release limit its applicability. Solid amine-based adsorbents are an emerging solution for DAC, but the adsorbents often suffer from problems such as rapid degradation and low CO₂ capacity.

Based on our preliminary results, amidine and guanidine -based superbases appear to be one of the best molecular structures for direct and reversible C02 capture from air. It has been demonstrated, that some of them can easily capture C02 at room temperature and atmospheric pressure. Even more, as shown in our preliminary studies, the release step in an appropriate medium requires only low temperatures. In this project, fundamental aspects of this phenomenon are further studied, new materials are developed, and possibilities to scale the process and to implement this technology at industrial scale will be evaluated.