No abstract

Isothermal vapor−liquid equilibrium data are presented for the 1,1,2,2-tetrafluoroethylene and 1,1,2,3,3,3-hexafluoroprop-1-ene binary system at (248.14, 263.01, and 282.89) K, with pressures ranging from (0.12 to 2.35) MPa. An apparatus based on the "static−analytic" method, equipped with a movable rapid online sampler−injector (ROLSI), was used to undertake the measurements. The combined expanded uncertainties are estimated at 0.11 K, 4 kPa, and 0.012 and 0.009 for the temperature, pressure, and the equilibrium liquid and vapor mole fractions, respectively. The experimental data were correlated with the Peng−Robinson equation of state using the Mathias −Copeman α function, together with the Wong−Sandler mixing rule utilizing the nonrandom two-liquid activity coefficient model.

In this work measurements and modeling of new phase equilibria data for systems related to natural gas processing were performed. A high-pressure apparatus functioning in the static synthetic mode was used to measure P–T–x data for the systems methane + methanol + 2,2′-[ethane-1,2-diylbis­(oxy)] di­(ethan-1-ol) (triethylene glycol (TEG)) (0.0333 methanol/0.9667 TEG wt fraction) and carbon dioxide + methanol + TEG (0.0333 methanol/0.9667 TEG wt fraction) at 303.16 and 323.15 K. Validation of the experimental technique was performed through measurement of P–T–x data for methane + TEG, methane + methanol, and carbon dioxide + water + TEG (0.0350 water/0.9650 TEG wt fraction) test systems from T = 298.15 to 323.15 K. The data were modeled using the Peng–Robinson equation of state with the Wong Sandler mixing rules (PRWS), the Cubic Plus Association (CPA) model, and the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) model, and predictions were performed with the predictive Soave–Redlich–Kwong (PSRK) model. For the methane + methanol + TEG and carbon dioxide + methanol + TEG systems, the PRWS model correlation yielded the best fit to the experimental data compared to the PC-SAFT and CPA models with a maximum absolute average relative deviation in pressure (AARD­(P)) not exceeding 0.0309.

A new 750 cm3 pilot test rig based on the “isochoric pressure method” was designed and commissioned for the hydrate measurements to concentrate sucrose solutions. The reactor included an improved agitation system and enabled sampling of the sucrose solutions. The experimental method was validated be performing dissociation measurements for the CO2 + water system. Gas hydrate kinetic and sampling data were measured for the CO2 + sucrose solutions at sucrose concentrations between (12–60) oBrix, within the temperature range of (274.65–276.15) K and at pressures up to 3.70 MPa. Results showed that sucrose is a kinetic inhibitor. The data were modeled to obtain hydrate formation rate, storage capacity, gas consumption and apparent rate constant. Stage‐wise concentration measurements were performed with reactor conditions at 274.65 K, 3.70 MPa and 130 rpm mixer speed with liquid sample withdrawal. A final sucrose product of approximately 60 oBrix was obtained.

A new apparatus based on the static total-pressure (staticsynthetic) method was designed and commissioned. The novelty of the apparatus involves the placement of the loading valves, allowing metering of components directly into the liquid phase of the equilibrium cell. The new apparatus was tested and the experimental procedure developed by measuring phase equilibrium data (T−P−z) for a number of different systems available in the literature. Three of these test systems are presented in this paper, namely, the binary systems of n-hexane + 2-butanol, n-pentane + 2-butanol, and n-pentane + ethanol at temperatures of 329.21, 317.17, and 303.11 K, respectively. The modeled data (T−P−x) compare well to data available in the literature. New T−P−z data were measured for the binary system of n-pentane + 2-propanol at temperatures of 313.11, 323.11, and 333.12 K. The T−P−x−y data were modeled using both the combined and direct method.