Thermal Properties and Phase Behavior of Water - n-pentane and Water - n-hexane Systems

Suleiman Rasulov

doi:10.4172/2161-0398.1000205

Abstract

The pvTx properties of H2O-n-C5H12 and H2O-n-C6H14 mixture have been measured in the temperature interval 303-680 K and pressure up to 60 MPa. Measurements were made along 265 liquid and vapor isochors in the density range 63-713 kg/m3. Measurements were made for 15 concentrations between 0.110 and 0.987 mole fraction of H2O for mixtures with C5H12 and 11 concentrations between 0.166 and 0.977 for mixtures with C6H14. The temperatures and pressures at the three-phase and two-phase boundary curves for the mixtures were obtained using the isochoric (p-T) break point technique. The critical properties data of the upper and lower branches of the critical curves were extracted from the derived phase boundary data. The measured three-phase data were used to estimate the value of the upper critical end point.

Highlights

Thermodynamic properties of water and hydrocarbon mixtures at high temperatures and pressures are of particular interest for the oil and chemical industries, organic chemistry, geology and mineralogy, new separation processes, and biology
The work presents the investigation results for phase equilibria of binary immiscible systems under standard conditions (n.hexanewater, n.pentane-water) basing on measurements of PVTx-properties in temperature intervals from 300 K to 680 K, pressures up 60 MPa, and a wide range of densities with a constant-volume piezometer
The equilibrium range between hydrocarbon liquid and gas phase is bounded by the three-phase equilibrium curve, the line of critical points lower locus, and the vapor curve of pure hydrocarbon

Summary

Introduction

Thermodynamic properties of water and hydrocarbon mixtures at high temperatures and pressures are of particular interest for the oil and chemical industries, organic chemistry, geology and mineralogy, new separation processes, and biology. Ermakova and Anikeev [8,9] used the Redlich-Kwong-Soave cubic equation at appropriate selection of binary interaction coefficients as a model for the estimation of phase states of complex mixtures under near-critical and supercritical conditions and for the description of gas-gas equilibrium.

Results

Conclusion