Phase Equilibria of Three Binary Mixtures: Methanethiol + Methane, Methanethiol + Nitrogen, and Methanethiol + Carbon Dioxide

International audienceNew vapor-liquid equilibrium (VLE) data for methanethiol (MM) + methane (CH 4), methanethiol (MM) + nitrogen (N 2), and methanethiol (MM) + carbon dioxide (CO 2) is reported for temperatures of (304, 334, and 364) K in the pressure range (1 to 8) MPa. A "static- analytic" method was used for performing the measurements. The objective is to provide experimental VLE data for methanethiol with other natural gas contents at its crude form, for which no data are available in the open literature. The new VLE data for the aforementioned systems have been modeled successfully with the cubic-plus-association equation of state (CPA EoS)

Phase Equilibrium Measurements and Modeling of 1-Propanethiol+1-Butanethiol + CH₄ in Methane Ternary System at 303, 336, and 368 K and Pressure Up to 9 MPa

International audienceNew vapor-liquid equilibrium (VLE) data for 1-propanethiol + 1-butanethiol + CH4 ternary system is reported. Measurements were performed at three different temperatures (303, 336 and 368 K), while the pressure was ranged from1 to 9 MPa. The total system pressure was maintained by CH4. The inlet mole fraction of 1-propanethiol (x = 5.43 10-1) and 1n-butanethiol (x = 4.56 10-1) in the liquid phase were same in all experiments. A static analytic method was used for performing phase equilibrium measurements. The new VLE data have been modeled successfully with Cubic-Plus-Association (CPA) EoS

VAPOR–LIQUID–LIQUID EQUILIBRIUM MEASUREMENTS AND MODELING OF METHANETHIOL OR ETHANETHIOL OR OR 1-BUTANETHIOL IN METHANE + WATER TERNARY SYSTEMS AT 303, 335, AND 365 K AND PRESSURE UP TO 9 MPA

International audienceSubmit your abstract below (400 words): Abstract: New vapor−liquid−liquid equilibrium (VLLE) data for methanethiol + methane + water, ethanethiol + methane + water, 1-propanethiol + methane+ water, and 1-butanethiol + methane + water ternary systems have been measured at three temperatures (303, 335, and 365 K) and pressures up to 9 MPa. A " static-analytic " method was used for performing all the measurements. The total system pressure was maintained by CH 4. The objective of this work is to provide experimental VLLE data with thermodynamic modeling for mixtures of mercaptans (thiols) with other natural gas contents at its crude form, for which no data are available in the open literature. Such data will help the industrial modeling of processes relevant to reduction of sulfur emissions. The Cubic-Plus-Association (CPA) equation of state was applied to describe the phase behavior of the investigated systems. It is shown that the CPA EoS satisfactorily describes the solubilities of mercaptans (thiols) in all phases. It is observed from the experimental data that the solubility of CH 4 in the aqueous and organic phases increases with an increase of the total system pressure and decreases with an increase of the temperature. However, the solubility of CH 3 SH in the aqueous and organic phases decreases slightly with an increase of the total system pressure and increases significantly with an increase of the temperature. The new VLLE data of ternary system were compared with predictions of the cubic-plus-association equation of state. The model tends to under predict the concentration of CH3SH in all phases, particularly the vapor phase. However, the model underestimates the water content of the vapor phase, especially at low pressures and at the highest investigated temperature, i.e., at 365 K. Only the ethanethiol + methane + water system showed significant cross-association effects. Furthermore, no cross association (solvation) was found to be significant in 1-propanethiol + methane + water and 1-butanethiol + methane +water ternary systems. Highlight 1: New vapor−liquid−liquid equilibrium (VLLE) data for methanethiol + methane + water, ethanethiol + methane + water, 1-propanethiol + methane+ water, and 1-butanethiol + methane + water ternary systems have been measured at three temperatures (303, 335, and 365 K) and pressures up to 9 MPa

Vapor–Liquid–Liquid Equilibrium Measurements and Modeling of the Methanethiol + Methane + Water Ternary System at 304, 334, and 364 K

International audienceNew vapor-liquid-liquid equilibrium (VLLE) data for methanethiol (CH 3SH) + methane (CH 4) + water (H 2O) have been obtained at three temperatures (304, 334, and 364 K) and pressures up to 9 MPa. A "static-analytical" method was used to perform all of the measurements. The objective was to provide experimental VLLE data for CH 3SH with other natural gas contents at its crude form for which limited or no data are available in the open literature. Such kinds of data are required for the industrial modeling of sulfur emissions. It is observed from the experimental data that the solubility of CH 4 in the aqueous and organic phases increases with an increase of the total system pressure and decreases with an increase of the temperature. However, the solubility of CH 3SH in the aqueous and organic phases decreases slightly with an increase of the total system pressure and increases significantly with an increase of the temperature. The new VLLE data of this ternary system were compared with predictions of the cubic-plus-association equation of state. The model tends to underpredict the concentration of CH 3SH in all phases, particularly the vapor phase

An overview of the thermodynamic models for acidgases in electrolyte solutions

Most of the thermodynamic models are structured with terms representing long range interactions or intermediate/short range interactions only. Thus for the proper thermodynamic presentation of electrolyte systems, all different types of interactions: ion-ion, ion-dipole, dipole-dipole, molecule-molecule should be taken into account. The potential energy caused by ion-ion interactions is inversely proportional to the separation between them. Electrostatic ion-ion interactions therefore are effective over a relatively long distance called as long range interactions. A review of the literature was conducted to find the available models, correlations: capable of describing the phase behavior and thermo physical properties of strong as well as weak electrolyte systems.  In this work the comparative study for the models that has been used for describing the Phase behavior of acid gases and sulfur species in alkanolamine aqueous solutions. These kinds of models are of high interest for the absorption unit in the natural gas processing industr

Volumetric properties of hexamethyleneimine and of its mixtures with water

International audienceDensities of pure hexamethyleneimine and of its aqueous Solutions have been measured at atmospheric pressure, using an Anton Paar digital vibrating tube densimeter, from 273.16 to 363.15 K and from 283.15 to 353.15 K, respectively. Acceptable representations of experimental data are found using a general correlation from Dauber et al. for pure hexamethyleneimine and using a general correlation from Bettin and Spieweck for pure water: thus indicating consistency of newly measured data. In this paper, we show the Redlich-Kister equation leads to incorrect data treatment particularly at low concentrations for systems presenting hydrophobic interactions. Thermal expansion coefficients (alpha*) for the pure hexamethyleneimine (HMI) and excess thermal expansion coefficient (alpha(E)) of the binary mixture: HMI + water at 283.15 and 298.15 K over the whole mole fraction range of water are presented and discussed in terms of the Structural changes in the mixtures

Densities, Apparent Molar Volume, Expansivities, Hepler’s Constant, and Isobaric Thermal Expansion Coefficients of the Binary Mixtures of Piperazine with Water, Methanol, and Acetone at T = 293.15 to 328.15 K

The properties of 3 binary mixtures containing piperazine were investigated in this work. In a first step, the densities for the two binary mixtures (piperazine + methanol) and (piperazine + acetone) were measured in the temperature range of 293.15 to 328.15 K and 293.15 to 323.15 K, respectively, at atmospheric pressure by using a Rudolph research analytical density meter (DDM 2911). The concentration of piperazine in the (piperazine + methanol) mixture was varied from 0.6978 to 14.007 mol/kg, and the concentration of piperazine in the (piperazine + acetone) mixture was varied from 0.3478 to 1.8834 mol/kg. On the other hand, the density data for the (piperazine + water) mixture were taken from the literature in the temperature range of 298.15 to 328.15 K. In a second step, for the 3 investigated systems, the apparent molar volume (Vϕ) and the limiting apparent molar volume (Vϕ0) at infinite dilution were calculated using the Redlich–Mayer equation. The limiting apparent molar volumes (Vϕ0) were used to study the influence of the solute-solvent and solute-solute interactions. The temperature dependency of the apparent molar volumes was used to estimate the apparent molar expansibility, Hepler’s constant ∂2Vϕ0/∂T2P, and isobaric thermal expansion coefficients αP

Effect of acid gases on the solubility of n-propylmercaptan in 50 wt% methyl-diethanolamine aqueous solution

International audienceIn this communication, we have measured the solubility and partition coefficient of n-propylmercaptan in 50 wt% MDEA aqueous solution at 366 K in the presence of single and mixed acid gases (CO 2 and H 2S). A static analytic method was used for performing all the measurements. Methane was used to maintain the total pressure of the system in equilibrium cell. The concentration of n-propylmercaptan in aqueous phase was in the 50-1000 ppm (mole) range. The effect of acid gas loadings on the physical and chemical solubility of n-propylmercaptan is discussed