Solubility of Carbon Dioxide in Secondary Butyl Alcohol at High Pressures: Experimental and Modeling with CPA

Mixtures of carbon dioxide and secondary butyl alcohol at high pressures are interesting for a range of industrial applications. Therefore, it is important to have trustworthy experimental data on the high-pressure phase behavior of this mixture over a wide range of temperatures. In addition, an accurate thermodynamic model is necessary for the optimal design and operation of processes. In this study, bubble points of binary mixtures of CO2 + secondary butyl alcohol were measured using a synthetic method. Measurements covered a CO2 molar concentration range of (0.10–0.57) % and temperatures from (293 to 370) K, with pressures reaching up to 11 MPa. The experimental data were modelled by the cubic plus association (CPA) equation of state (EoS), as well as the more simple Soave–Redlich–Kwong (SRK) EoS. Predictive and correlative modes were considered for both models. In the predictive mode, the CPA performs better than the SRK because it also considers associations

Vapor-liquid equilibria of binary and ternary mixtures of acetaldehyde with Versatic 9 and Veova 9

\u3cp\u3eIn continuation of our earlier publication on the phase behavior of binary and ternary mixtures involving acetaldehyde, Versatic 10, and Veova 10, in this work we present bubble-point pressures of the binary and ternary systems of acetaldehyde, Versatic 9, and Veova 9. The measurements were carried out in the Cailletet equipment, which operates according to the synthetic method. The solubility data are presented within a temperature range of 298-353 K for the two binaries of acetaldehyde + Versatic 9 and acetaldehyde + Veova 9. The pressures required for complete solubility into one homogeneous phase ranged from 0.083 to 0.414 MPa in the temperature and concentration range considered. While both Versatic and Veova contain a C=O group, Versatic also contains an alcoholic OH, which makes its solubility in acetaldehyde more difficult. The solubility curve of Versatic 9 not only shifts to higher pressures compared to that of Veova 9, but also has an increased curvature, indicating its greater deviations from ideality. As the alkyl chain is increased by one carbon number to Veova 10 and Versatic 10, the absence and presence of the OH group in Veova and Versatic also result in greater and smaller curvatures of the solubility curves, respectively. The Peng-Robinson (PR) and Soave-Redlich-Kwong (SRK) equations of state were used to model phase equilibria of the binary systems of acetaldehyde + Versatic 9 and acetaldehyde + Veova 9. Results showed that both models have good agreement with the experimental values in this study. Two ternary mixtures of acetaldehyde + Versatic 9 + Veova 9 were also investigated experimentally for their bubble point pressures. While both components have one C=O group, Versatic 9 also contains an alcoholic OH, which Veova 9 lacks. Therefore, nonideal interactions are increased between the molecules of acetaldehyde and Versatic 9 due to the presence of this hydrogen-bonding group, as compared to the system of acetaldehyde + Veova 9.\u3c/p\u3

Bubble point pressures of binary system of methanol and methyl propionate

\u3cp\u3eIn this work, bubble point pressures of the system of methanol + methyl propionate were measured for several isopleths within temperature and pressure ranges of 382-444 K and 0.437-2.285 MPa, respectively. The vapor pressures of pure methanol and methyl propionate were also measured. The two-suffix Margules equation was used to represent the nonidealities of the liquid phase and the virial equation of state was used to take into account the nonidealities of the vapor phase. The temperature-dependent parameter of the two-suffix Margules equation was determined using Barker's method. The results show that the model can successfully estimate the bubble points of this system with average errors less than 0.69%.\u3c/p\u3

EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF PROMOTER-STABILIZED CLATHRATE HYDRATES OF NOBLE GASES

It has been found that helium gas can stabilize the THF hydrate (of the sII type). Dissociation temperatures of the binary He-THF hydrates are significantly higher than those of pure THF hydrates at the same pressure. In order to investigate the distribution of He molecules within the cavities of this hydrate, Grand Canonical Monte Carlo simulations have been utilized. A wide pressure range (up to 700 MPa) has been examined. The results of these simulations show that the small cavity of the binary He-THF hydrate is able to accommodate up to three He molecules resulting in a He content of 6.0 wt. % at 700 MPa. Contrary to the similar case of binary H2-THF hydrate, He content as a function of pressure does not present a plateau, at least over the pressure range examined. Moreover, similar simulations on a hypothetical sII hydrate of pure He show that the large cavity of this hydrate could be occupied by up to ten He molecules in the pressure range under question.Non UBCUnreviewe

Experimental phase behavior study of a five-component model gas condensate

In this work, the bubble points and dew points of a multicomponent mixture of methane, butane, heptane, decane and tetradecane as a model mixture representative of a gas condensate, have been measured experimentally. Ten samples with approximately the same composition were prepared and their bubble-point and/or their dew-point pressures were measured at several temperatures. The phase-behavior measurements were carried out in the temperature range of 240–410 K, and at pressures up to 21.6 MPa. The temperature and pressure ranges of the critical point for this system was measured and the cricondenbar and cricondentherm of the phase envelope were determined. The Peng–Robinson equation of state (PR EOS) was used for modeling of the phase behavior of this system. The PR EOS was able to successfully determine the bubble- and dew-points of this model gas condensate. Using the PR EOS, the retrograde region and liquid drop out characteristic of this model gas condensate were determined

Vapor-liquid equilibria of the binary system 1,5-hexadiene + allyl chloride

Knowledge of accurate vapor–liquid equilibrium data for mixtures of allyl chloride and 1,5-hexadiene is important for several industrial purposes. The bubble points of binary mixtures of allyl chloride and 1,5-hexadiene have been measured experimentally using a synthetic method. Measurements were carried over concentrations ranging from (0 to 1) mol % of allyl chloride. The vapor–liquid equilibrium is presented at temperatures ranging from (25 to 100) °C. Within this temperature range, bubble-point pressures up to 5 bar were observed. The experimental results indicated that, as the concentration of allyl chloride increases in the mixture, higher pressures are necessary for a complete dissolution of the two components. In addition, solubility pressures increase as temperature increases for a mixture of fixed compositio