P-T-x measurement and modelling of (methane plus propane plus methanol plus water plus TEG) and (methane plus propane plus carbon dioxide plus methanol plus water plus TEG) systems

Phase equilibria data for multicomponent mixtures containing methane, propane, carbon dioxide, methanol, water, 2,2 '-(Ethane-1,2-diylbis(oxy))diethanol) or triethylene glycol at high-pressure conditions typical to natural gas treating and transportation systems are not readily available in the literature. These data are essential as they contribute to the information required for the process design, control and monitoring of methanol and/or TEG in gas conditioning systems. In this study, new phase equilibria data were measured and modelled for methane + propane + methanol + water + TEG and methane + propane + carbon dioxide + methanol + water + TEG systems over a temperature range of 283.15-323.15 K and pressures up to 14 MPa. The static synthetic method was utilised for the P-T-x measurements and the data were modelled using the Cubic Plus Association model. The modelling approach included regression of binary interaction parameters for relevant binary pairs.