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.

Polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane combined with polyvinylidene fluoride-graft-2-hydroxyethyl acrylate (PVDF-g-PHEA) was fabricated via non-solvent induced phase separation (NIPS). In this study, PVDF-g-PHEA was synthesized via atom transfer radical polymerization (ATRP) method, and then synthesized graft copolymer was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and thermogravimetry analysis (TGA). Moreover, PVDF membranes containing graft copolymer (PVDF-g-PHEA) showed lower water contact angle value than pristine PVDF membranes. Macrovoid holes were also observed in cross sectional scanning electron microscope (SEM) image of PVDF membrane containing PVDF-g-PHEA. Accordingly, it was confirmed that these characteristics led PVDF membrane blended with graft copolymer has high final permeate flux and normalized flux compared to pristine PVDF membrane.

As one of the carbon capture and utilization (CCU) technologies, mineral carbonation which has been introduced to reduce the carbon dioxide (CO₂) concentration in the atmosphere is a technology that makes it possible to capture CO₂ and recycle byproducts as resources. However, existing mineral carbonation requires additional energy and costs, as it entails high temperature and high pressure reaction conditions. This study compared two processes which electrolyze NaCl and CaCl₂ solution to produce CO₂ absorbent needed to generate CaCO₃, and which were conducted at room temperature and pressure unlike existing mineral carbonation. As a result, high-purity calcite was obtained through Process 1 using NaCl solution, and aragonite and portlandite were obtained in addition to calcite through Process 2 (two steps) using CaCl₂ solution.