Equilibrium solubility of H2S in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

Abstract

Experimental values for the gas solubility of hydrogen sulphide (H2S) in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T=(313.15 and 393.15)K, over the pressure range of (51.4 to 1467.6)kPa. The concentrations of the aqueous MIPA solutions studied were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are reported as partial pressure of H2S, pH2S, against its liquid mole ratio, aH2S (mol H2S·mol−1 MIPA), and against its mole fraction in the solvent, xH2S. The experimental results show that the solubility of H2S increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA.The physicochemical model of Kent and Eisenberg was used to regress simultaneously all the experimental results of the solubility of H2S in the four studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The standard deviation of the regression for pressure is 68.0kPa using 69 experimental solubility points.The new experimental solubility results of H2S were compared with those reported in the literature for aqueous solutions of diethanolamine (DEA), diisopropanolamine (DIPA), N-methyldiethanolamine (MDEA), and 2-amino-2-methyl-1-propanol (AMP), under similar conditions of temperature and amine concentration. From this comparison, it is concluded that aqueous solutions of MIPA are a good solvent alternative to use in industrial gas purification processes at relatively high pressures, since the magnitude of the H2S solubility results in MIPA solutions was found to be higher than that in aqueous solutions of MDEA, DEA, and DIPA.