Formulation of Liquid-Liquid and Solid-Liquid Nanodispersions for CO2 Capture

Abstract Environmental constraints make CO2 reduction a high-priority challenge for energy generation processes. Finding new alternatives for removal of CO2 from flue gases at relatively low cost has been the driving force for emerging technologies. Traditional amine scrubbing needs to be replaced by more feasible processes from both economic and environmental points of view. The application of surface science to create systems with enhanced capacity to capture/absorb CO2 has been mainly focused on producing aqueous dispersions of solid metal nanoparticles; those systems have a low concentration of nanoparticles (generally less than 1 wt.%), however their interfacial area is high. This work presents the preparation of nanoparticle dispersions and nanoemulsions for CO2 absorption applications by using a low energy method. All systems are comprised of three main elements: water, oil (nanoemulsions), organic solid (nanoparticle dispersions), and surfactants (mixture of a non-ionic and cationic surfactant). Many systems were prepared and characterized in terms of stability and particle size. All the tested nanofluids were able to enhance the CO2 absorption into water in experiments conducted in a pressurized cell. In contrast, only nanoemulsions improved the CO2 absorption into aqueous solutions of diethanolamine (DEA). These promising results open the door to using the concepts of physicochemical formulation of surfactant-oil-water systems to reduce the carbon footprint.