Vapor-liquid equilibria, solid-vapor-liquid equilibria and H2S partition coefficient in (CO2 + CH4) at temperatures between (203.96 and 303.15) K at pressures up to 9 MPa

Abstract

Vapor-liquid equilibrium (VLE) measurements of the (CO2 + CH4) system are reported along seven isotherms at temperatures varying from just above the triple point to just below the critical point of CO2 at pressures from the vapor pressure of pure CO2 to approximately 9 MPa, including near-critical states. From these data, the critical locus has been determined and correlated over its entire length. The VLE data are correlated with the Peng-Robinson equation of state (PR-EoS), using a temperature-dependent binary interaction parameter, and also compared with the predictions of the GERG-2008 equation of state. The former represents the phase compositions across all isotherms with a root-mean-square molefraction deviation of S = 0.0075 while, for the latter, S = 0.0126. Measurements of the three-phase solidvapor-liquid equilibrium (SVLE) line are reported at temperatures from approximately (204 to 216) K and a new correlation is developed which is valid from 145 K to the triple point of CO2. Additionally, we report the partitioning of trace levels of H2S between coexisting liquid and vapor phases of the (CO2 + CH4) system and compare the results with the predictions of the PR-EoS.

Review on the Mechanism of CO2 Storage and Enhanced Gas Recovery in Carbonate Sour Gas Reservoir

“…Zhang [20] conducted a phase simulation study of the coexistence systems of natural gas and water containing CO 2 and H 2 S, and conducted the sensitivity analysis of pressure, temperature, water content, and other factors. In the experiment of CO 2 -H 2 S coexistence systems, Theveneau [21] and Souza [22], have conducted phase equilibrium experiment of CO 2 -H 2 S-CH 4 system. Zhang [23] conducted a phase equilibrium experiment of CO 2 -H 2 S-crude oil system.…”

Phase Behaviour of Isobutane + CO2 and Isobutane + H2 at Temperatures between 190 and 400 K and at Pressures up to 20 MPa

“…The vapour-liquid equilibrium (VLE) apparatus used in this work, shown in Figure 1, has been described in several previous publications [30][31][32], so not all details are described fully here, although modifications made since the previous publications are detailed. The technique employed was the static-analytic or analytical-isothermal method [33], where the vapour and liquid phases of a mixture in equilibrium at a known temperature and pressure are sampled and their compositions quantitatively analysed, in this case by gas chromatography (GC).…”

“…Calibration of the GC system was performed in the manner described previously, employing the absolute-area method, the accuracy and effectiveness of which is well validated [30][31][32].…”

“…The uncertainty analysis in this work follows the same methodology as previous publications [30][31][32]38] guided by the 'Evaluation of Measurement Data -Guide to the Expression of Uncertainty in Measurement" recommended by NIST [39]. For the determination of the composition, 𝑧 𝑖 , of the liquid, 𝑥 𝑖 , or vapour, 𝑦 𝑖 , phases, the measured quantities were the temperature, 𝑇, pressure, 𝑝, and the chromatographic peak areas, 𝐴 𝑖 .…”

Experimental and Theoretical Study of CO2 Solubility in Liquid CH4/H2 Mixtures at Cryogenic Temperatures

“…Fandinõ et al 11 reported vapor−liquid equilibrium data for CO 2 /H 2 and CO 2 /N 2 binary systems at temperatures between −55 and 30 °C at pressures ranging from the vapor pressure of CO 2 to approximately 15 MPa. Souza et al 12 carried out vapor−liquid equilibrium (VLE) measurements of a CO 2 /CH 4 binary system along seven isotherms at temperatures varying from just above the triple point to just below the critical point of CO 2 at pressures from the vapor pressure of pure CO 2 to approximately 9 MPa, as well as measurements of the three-phase solid−vapor−liquid equilibrium (SVLE) line at temperatures from approximately −67 to −57 °C. Lin et al 13 set up a VLE experimental apparatus based on the static analytic method to measure VLE data for the H 2 /CH 4 system at temperatures ranging from −173.2 to 142.5 °C and pressures below 3.5 MPa.…”