Experimental Measurements and Predictions of Gas Hydrate Dissociation Conditions in the Presence of Methanol and Ethane-1,2-diol Aqueous Solutions

Abstract

In this work, experimental hydrate dissociation conditions of methane in the presence of 0.06, 0.10, and 0.20 mass fractions of methanol and 0.10 and 0.25 mass fractions of ethane-1,2-diol in aqueous solutions are reported. In addition, phase equilibria of a ternary mixture of methane (0.9319 mole fraction) + ethane (0.0481 mole fraction) + propane (0.02 mole fraction) in the presence of 0.25 mass fraction of ethane-1,2-diol aqueous solution is investigated. A high-pressure equilibrium cell is used for measurement of hydrate dissociation conditions in the temperature range of (265.4 to 282.0) K and pressure range of (1.97 to 6.96) MPa. The experimental gas hydrate dissociation conditions are modeled using the van der Waals and Platteeuw (vdW-P) solid solution theory for dealing with the hydrate phase and the Valderrama–Patel–Teja equation of state (VPT-EoS) along with the nondensity dependent (NDD) mixing rules to account for the fluid phases. The obtained experimental data are finally compared with selected experimental data from the literature as well as the model predictions, and acceptable agreements are observed.

Experimental measurement and thermodynamic modelling of hydrate phase equilibrium conditions for krypton + n -butyl ammonium bromide aqueous solution

“…The isochoric pressure search method was used to perform the hydrate dissociation measurements for the krypton + TBAB + water system [48][49][50][51]. At the start of the measurements, the cell was evacuated using an Edwards vacuum pump to a pressure of 0.0003 MPa for approximately 30 minutes to remove air and any contaminants from previous experiments.…”

“…A step-change of 0.1 K per hour was used in the vicinity of the dissociation point. The point corresponding to the sharp change of the slope of the pressure−temperature plot is taken to be the final dissociation point [46][47][48][49][50][51]. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 8 Figure 1 shows an example of the cooling and heating curve for the determination of the hydrate dissociation point.…”

Semi-clathrate hydrate phase stability conditions for methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) + water system: Experimental measurements and thermodynamic modeling

“…Thereupon, the cell was pressurized with the methane gas to reach the required pressure. The isochoric pressure search method [48][49][50][51][52] was employed to measure the semi-clathrate hydrate phase equilibrium conditions. Initially, the pressure was adjusted to the pressure higher than the equilibrium pressure required for the semi-clathrate hydrate dissociation.…”

Experimental and Modeling Studies on the Prediction of Gas Hydrate Formation

“…Hydrate Growth Dynamic. During the hydrate formation process there is transfer phenomena in the hydrate-gas-water [17][18][19]. The kinetic observation of hydrate formation process is shown in Figure 1.…”