N۲-bubbling Method for O۲ Removal from the Loaded MEA Solution in the CO۲ Capture Process

Flue gas stream contains full-oxidized (carbon dioxide), partially oxidized hydrocarbons, and some extent of oxygen. Carbon dioxide can be separated by CO۲ capture and separation (CCS) process using monoethanolamine (MEA). In this process, CO۲ accompanied with O۲ can be absorbed by the solution (MEA+H۲O). Dissolved molecular oxygen may explicitly participate in the cathodic reaction and generate sever corrosion problems, or it may induce amine degradation via irreversible oxidative reaction, reducing amine efficiency. In this research, the method of N۲-bubbling was investigated for deoxygenation of loaded aqueous MEA solution on a laboratory scale. N۲-bubbling set-up was simulated with a known volume glass vessel in which bubbling of N۲ with an available flow rate was applied through the loaded amine solution. A mathematical formula was developed to correlate the N۲-bubbling flow rate, F, the volume of amine solution in the bubbling column, V, and time taking the oxygen concentration decreases from saturated O۲-solution to less than ۰.۵ mg/L.

Keywords:

CO۲ capture , De-oxygenation , Dissolved oxygen , monoethanolamine solution , N۲-Bubbling