Experimental Design and Data Analysis for Accurate Estimation of Reaction Kinetics and Conversion for Carbon Mineralization

Abstract

Silicate minerals such as olivine (Mg2SiO4) and serpentine [Mg3(OH)4(Si3O5)] can react with CO2 to form mineral carbonates to permanently store CO2. Despite significant advancements in carbon mineralization, major discrepancies in the reported kinetics exist because of inconsistencies among various experimental methodologies, the heterogeneity and aging of the minerals, and inadequate fast kinetics and morphological data to probe the reaction mechanisms. In this work, it was found that aged and freshly ground olivine produce very different carbonation yields. A new mineral cleaning protocol to remove fines (<5 μm) was developed. Fast and slow serpentine dissolution regimes were distinguished using a custom-built differential-bed reactor. Mineral carbonate formation using a bubble-column reactor was described. Different carbon analyses were evaluated for accurate estimation of the extent of carbon mineralization. Therefore, this study focused on the development of an experimental framework and a data analysis method for the systematic investigation of mineral dissolution and carbonation behaviors.