Carbon Dioxide Fixation by Combined Method of Physical Absorption and Carbonation in NaOH-Dissolved Methanol

摘要

The present study investigates the potential of a process as one of the carbon capture and storage/utilization (CCSU) technologies. The process involves a technology that combines the CO2 physical absorption and mineral-carbonation in NaOH-dissolved methanol and includes CO2 desorption and methanol regeneration. Sodium Methyl carbonate (SMC) is precipitated as CO2-fixing material in relatively highly concentrated NaOH solution and the amount of CO, physically absorbed is estimated to be approximately 4.36 g CO2/500 mL methanol at ambient condition. The CCSU capacity of the process based on the gas phase and cake weight measurement is calculated to be 11.02g CO2/(6 g NaOH/500 mL methanol) and 10.17 g CO2/(6 g NaOH/500 mL methanol), respectively. The amounts of CO, desorbed and CO2 fixed by SMC as well as Na2CO3 via the evaporation of solution that remains after carbonation are estimated to be 5.64 g CO2/(6 g NaOH/500 mL methanol) and 4.53 g CO2/(6 g NaOH/500 mL methanol), respectively. Therefore, the CO2 capture and fixation ratio of the process was calculated to be 55.46% and 45.54%, respectively. Although the overall methanol recovery ratio is calculated to be 90.1%, the loss can be further substantially reduced during the process by employing more advanced equipment and carrying out a more detailed operation. In addition, precipitated SMC separated methanol can be reused for the subsequent carbonation without any treatment.