Laboratory-scale experiment on a novel mineralization-based method of CO2 capture using alkaline solution

We propose a novel CO2 conversion technology that is based on use of an alkaline solution. In this investigation, alkaline solutions were used to fix CO2 in the presence of K+, Na+, and Ca2+ ions. NaOH and KOH were selected and used at a 30 wt% in H2O. All the experiments were conducted under normal temperature and pressure conditions to reduce the total energy in the system. We also used a 30 wt% mono-ethanolamine (MEA) solution to make a comparison with the selected alkaline solution. Metal ions were supplied as Ca2+ from a CaO solution. The product precipitate was then analyzed by X-ray diffraction. We found that the selected alkaline solution formed a metal carbonate by reacting with injected CO2. The NaOH and KOH solutions reacted directly with the CO2. The NaOH did not form CaCO3 in the first conversion experiment. However, its CO2 reduction capacity was dramatically increased after a CaO solution was added. In addition, we believe that the formed precipitates could be used in various industries. Therefore, this research contributes not only to the basic research into alternatives to the use of an MEA solution for CO2 fixation, but may also be applicable to CO2 reduction technologies.