Multicomponent Vapor-Liquid Equilibrium Measurements and Modeling of Triethylene Glycol, Water, and Natural Gas Mixtures at 6, 9 and 12.5 Mpa

Triethylene Glycol Solubility in High-Pressure Methane: New Experimental Data at 40 to 60 °C

“…These authors concluded that the best approach was to use a new set of parameters with the 4F association scheme. The more recent papers from this research group however 4,5 confirm that the 4C data set proposed by Derawi et al 9 provides the best data fit when their more extensive experimental data set is used.…”

“…The inlet methane pressure was adjusted by a two-stage pressure regulator (PR-1, from BOC Limited) with a maximum outlet pressure of 300 bar. A sliding-stem digital flow controller was used to enable low flow rates (mL/min) at pressures up to 180 bar (CV-1, Fisher Baumann 51,000 Series, Western Process Controls Vic), which Literature data is from Qvistgaard et al, 4 Fisher et al, 7 Jerinic et al, 8 and Trancosco et al 5 Simulations use the CPA equation of state (eq 1) with parameters from Derawi et al 9 and a binary interaction parameter of k ij = 0.136 or 0.1634. was driven by an external power source providing 4−20 mA and 8−30 V. The gas passed in turn through three stainless steel 300 mL cylinders (E-1, E-2, and E-3, Swagelok Australia) each equipped with a central distribution tube, packed with spherical stainless steel beads for effective gas−liquid contact, and filled with liquid TEG. The use of three consecutive cylinders ensured that the gas exiting the last cylinder was at equilibrium.…”

“…Similarly, Arya et al 3 note that "some new experimental data have to be obtained in order to conf irm the existing data sets for the TEG content of a methane vapor phase'". During the preparation of this manuscript, new data was presented by Qvistgaard et al 4 and Trancoso et al 5 which adds to the experimental database. However, much of this data was collected at 25 °C or below, and all experiments contain between 15 and 300 ppm of water vapor.…”

“…However, much of this data was collected at 25 °C or below, and all experiments contain between 15 and 300 ppm of water vapor. In Qvistgaard et al, 4 "real" and "synthetic" gas mixtures are used that contain water vapor, CO 2 , and heavier hydrocarbons. These authors note that at some experimental conditions, the "synthetic" gas contains significantly more TEG than the "real" gas, possibly due to a solvation effect from the higher concentrations of CO 2 .…”

“…These authors note that at some experimental conditions, the "synthetic" gas contains significantly more TEG than the "real" gas, possibly due to a solvation effect from the higher concentrations of CO 2 . 4 All workers note the difficulty in obtaining accurate vapor pressure data due to the extremely low TEG concentrations being measured.…”