CO₂ Fixation by Membrane Separated NaCl Electrolysis

Atmospheric concentrations of carbon dioxide (CO₂), a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS), which is regarded as the most effective way to reduce such atmospheric CO₂ concentrations, has several environmental and technical disadvantages. Carbon capture and utilization (CCU), which has been introduced to cover such disadvantages, makes it possible to capture CO₂, recycling byproducts as resources. However, CCU also requires large amounts of energy in order to induce reactions. Among existing CCU technologies, the process for converting CO₂ into CaCO₃ requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO₃ stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO₃ was precipitated at room temperature and pressure. Following the experiment, the resulting product CaCO₃ was analyzed with Fourier transform infrared spectroscopy (FT-IR); field emission scanning electron microscopy (FE-SEM) image and X-ray diffraction (XRD) patterns were also analyzed. The results showed that the CaCO₃ crystal product was high-purity calcite. The study shows a successful method for fixating CO₂ by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO₃.