Hydrate phase equilibria of the guest mixtures containing CO2, N-2 and tetrahydrofuran

The three-phase, hydrate-water-rich liquid-vapor (HLV), equilibria of the b inary guest mixtures containing CO2 and N-2 were determined at the temperat ure range of 272-275 K and different compositions of vapor phase. In additi on, two phase equilibria of hydrate and vapor were also measured at three i sothermal conditions of 274, 277 and 278 K. The resulting P-x diagram indic ates that CO2 can be more contained than N-2 in the hydrate phase. More tha n 96 mol% CO2 in the mixed hydrate phase was obtained from a gas mixture of 17 mol% CO2 and 83 mol% of N-2 at 274 K. The addition of tetrahydrofuran ( THF) as a hydrate promoter extended hydrate stability region by elevating e quilibrium dissociation temperature and lowering pressure. The overall hydr ate equilibrium results were found to agree well with the calculated ones. (C) 2001 Elsevier Science B.V. All rights reserved.