Solubility of carbon dioxide gas in some 2.5 M tertiary amine aqueous solutions

Abstract Solubility of carbon dioxide (CO 2 ) acid gas in aqueous solutions in 2.5 mol/l tertiary amines, such as 2-(2-(dimethylamino) ethoxy) ethanol [DMAEOE], 3-dimethyl amino-1-propanol [DiMAP], 1,2-bis (dimethyl amino) ethane [TEMED], pyridine and methyl-4-morpholine has been measured at [313 and 353] K, and over the pressure range (0–200) kPa, using a specifically built apparatus based on the static method. The vapor pressures and the densities of these aqueous solutions, also, have been measured by a static method and picnometry, respectively. For validation of the experimental procedure, solubility of acid gas CO 2 in 2.5 mol/l aqueous solutions of mono-ethanolamine (MEA) and 2-amino-2-methyl-1-propanol (AMP) has been measured at 313.15 K. The experimental solubility results are presented in the form of the partial pressure of CO 2 versus the mole ratio α (mol CO 2 /mol amine), at each temperature. The solubility of gas CO 2 , in all the investigated aqueous amines, decreases with an increase of the temperature and increases with increasing partial pressure of CO 2 gas at a given temperature. The values of the solubility of CO 2 gas are in the following sequence: Pyridine