In a significant stride towards carbon neutrality and efficient CO2 recycling, researchers have discovered a novel approach to enhance the capture of low-concentration CO2 using blended ionic liquids. This breakthrough, published in the Journal of Carbon Dioxide Utilization, could have substantial implications for the energy sector, particularly in reducing energy consumption and improving the economics of carbon capture processes.
The study, led by Yu Nagai Kanasaki from the Research Institute for Chemical Process Technology at the National Institute of Advanced Industrial Science and Technology (AIST) in Japan, explored the potential of mixing aminium and acetate ionic liquids (ILs) to boost CO2 capture efficiency. The team focused on the mixtures of N-2-hydroxyethyl-aminoethylaminium bis(trifluoromethanesulfonyl)imide (1·[Tf2N]) and 1-ethyl-3-methylimidazolium acetate ([C2mim][AcO]), comparing them with mixtures of [C2mim][Tf2N].
The results were promising. The mixtures exhibited lower density and viscosity than the pure aminium IL, leading to faster absorption and desorption kinetics. “This is crucial for reducing energy consumption in the capture process,” Kanasaki explained. Moreover, mixtures containing 10 and 30 mol% 1·[Tf2N] absorbed more CO2 than the pure ILs at partial pressures up to 10 kPa, with a lower absorption heat than pure 1·[Tf2N].
The enhanced performance was attributed to the formation of nonionic components via proton recombination and the suppression of ammonium formation. “The proton sharing between the CO2 adduct and the [AcO]− anions plays a significant role in this process,” Kanasaki noted. Furthermore, blending [C2mim][AcO] with other aminium ILs showed even greater CO2 absorption capabilities at low partial pressures, offering higher CO2 solubility and lower enthalpy.
The findings suggest that mixing aminium ILs with [C2mim][AcO] is a viable alternative to chemical modification for developing CO2 separation materials. This approach could be applicable to various aminium ILs, opening up new avenues for innovation in the field.
The commercial impacts of this research are substantial. Enhanced CO2 capture technologies can lead to more efficient and cost-effective carbon capture and storage (CCS) processes, which are critical for reducing greenhouse gas emissions from power plants and industrial facilities. Additionally, improved CO2 capture can facilitate the development of carbon recycling technologies, converting captured CO2 into valuable chemicals and fuels.
As the world grapples with the challenges of climate change, innovations in CO2 capture and utilization are more important than ever. This research offers a promising path forward, demonstrating the potential of blended ionic liquids to enhance the efficiency and reduce the energy consumption of CO2 capture processes. With further development and commercialization, this technology could play a significant role in achieving carbon neutrality and building a more sustainable future.