Heats of mixing of gaseous CO2/CH4 mixtures with aqueous solutions of methyldiethanolamine and diethanolamine

The heats of mixing of gaseous CO2/CH4 mixtures with aqueous solutions of m ethyldiethanolamine and diethanolamine have been determined using an isothe rmal flow calorimeter. Data were collected at 26.7, 76.7 and 126.7 degrees C, at total pressures of 1.38, 3.45 and 6.90 MPa, with aqueous amine concen trations of 20, 35 and 50 wt%. The nominal partial pressure of CO2 in the g aseous feed stream was 0.069 MPa at a total pressure of 1.38 and 0.69 MPa a t 3.45 and 6.90 MPa total pressure. A model developed to predict thermodyna mic properties of these systems includes reaction equilibria, dissolution o f methane, vapor-phase non-idealities, vaporization of water and amines in addition to the acid gas absorption. (C) 2000 Elsevier Science B.V. All rig hts reserved.