Experimental Research System and Efficiency Evaluation Method of CO<sub>2</sub> Sequestration in Basalt Mineralization
Yaping Wang, Ying Chen, Wenyang Wang, Fujie Jiang, Wenchao Dou, Min Su, Zhidong Bao
Abstract
Basalt offers a promising method for safe and permanent CO 2 storage on a large scale. Currently, most experiments focus on the reactivity and mineralization kinetics of basalt and CO 2, often without accurately quantifying the reactions or considering the influence of carbonate rocks present in basalt, leading to inaccurate and complex results. The study conducted CO 2 water–rock reaction experiments under various conditions using a self-designed high-temperature and high-pressure reactor. The qualitative verification of changes before and after the reaction was done using X-ray diffraction (XRD) and scanning electron microscopy with an energy-dispersive spectrometer (SEM–EDS). Subsequently, the mineralization reaction efficiency was calculated by refining pressure data and a numerical model, and the results were validated using the improved total inorganic carbon (TIC) method. The results indicated the following: (1) various forms of calcium carbonate crystals were observed and confirmed post mineralization reaction. (2) Following the reaction, the feldspar and pyroxene in basalt decreased, the calcite content slightly increased, and a new amorphous phase formed. (3) Mineralization efficiency was assessed by combining pressure data from the instrument with a numerical model. The calculation results of the carbon sequestration efficiency (CSE) were consistent with the TIC method, confirming the system’s reliability. This method effectively addresses the issues of inaccurate and complex mineralization reaction efficiency evaluation and can contribute to research on basalt–CO 2 reaction ability and mineralization reaction kinetics.