Characteristics of Total Dissolved CO2 In Water using a CO2 Dissolving Device

In this study, we developed a CO₂ water dissolving device and evaluated its operational characteristics and efficiency. Additionally, we defined the total dissolved CO₂ (TDC) concentration to quantify the amount of CO₂ dissolved in water and proposed a new method to calculate TDC based on pH and total alkalinity. Initially, TDC concentrations were measured with circulating water at pH levels of 5.0, 6.0, and 7.0 to evaluate the characteristics of CO₂ dissolution. Under a dissolution tank pressure of 4.0 kgf/ ㎠ and a gas-to-liquid (G/L) ratio of 0.2, the TDC concentration of the circulating water reached 2,710 - 4,050 mg/L as CO₂ within 30 minutes. Furthermore, to determine the maximum TDC concentration, the device was operated for 180 minutes at a pH of 7.0. CO₂ was continuously dissolved for up to 150 minutes under system conditions of 4.0 kgf/ ㎠ tank pressure and G/L ratio of 0.1. The maximum TDC concentration was 10,064 mg/L as CO₂, exceeding 690% of the theoretical saturation concentration. These results indicate that CO₂ can be stably captured using water as a solvent.