Solubility of carbon dioxide gas in some 2.5 M tertiary amine aqueous solutions
Résumé
Solubility of carbon dioxide (CO2) 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 CO2 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 CO2 versus the mole ratio α (mol CO2/mol amine), at each temperature. The solubility of gas CO2, in all the investigated aqueous amines, decreases with an increase of the temperature and increases with increasing partial pressure of CO2 gas at a given temperature. The values of the solubility of CO2 gas are in the following sequence: Pyridine < Methyl morpholine < DMAEOE < TEMED < DiMAP.