Formation and polymorph transformation trends of metal carbonate in inorganic CO2 conversion process using simulated brine: Study for post-treatment of industrial brine via CO2 conversion

Abstract

To improve inorganic carbon capture utilization (CCU) technology, practical solution for global warming technology, we studied the formation and transformation trends of mineral carbonation using simulated brine. we converted CO2 into inorganic compounds, metal carbonate, using CO2 saturated aqueous monoethanolamine (MEA) solution. The produced metal carbonate varied according to the simulated brine's cation component, resulting from ion interactions in the system. It turns out that the common ion effect, which occurred due to the system's ion interactions involving changes of ionic atmosphere and salinity of the system, was the main reason for the various carbonation trends. Salting- out effect dominantly occurred in the single precipitation system whereas salting-in effect occurs in multi precipitation system (system CM and system CMN). However, salting-out effect also occurred in system CMN because of Na+. Moreover, we also found that Na+, which was overlooked in prior studies regarding polymorph transformation, also affects polymorph transformation. The interactions between the abovementioned effects involved the variation in the results. This variation interrupted the wide usage of the technology. However, through the study, we suggest ambient estimation of the final product with cation component. It would help future studies and demonstration of the inorganic CCU technology using brine.