Jean-Noël Jaubert

Modeling the Solubility of Carbon Dioxide in Imidazolium-Based Ionic Liquids with the PC-SAFT Equation of State

The goal of this work was to check the ability of the PC-SAFT equation to represent the solubility of carbon dioxide (CO(2)) in ionic liquids. Parameters of pure imidazolium-based ionic liquids were estimated using experimental densities over a large range of temperatures and then correlated with respect to the molecular weight and structure of the solvents. It was found that such a correlation is able to predict the density with high accuracy. The solubility of carbon dioxide in such ionic liquids was then studied. The binary interaction parameter k(ij) needed for the representation of such binary systems was first fitted to experimental liquid-vapor equilibria data. In a second step, a correlation based on the group contribution concept was developed to determine this temperature-dependent parameter. The ability of the model to describe accurately carbon dioxide solubility in imidazolium-based ionic liquids is demonstrated.

Activity coefficients at infinite dilution of organic compounds in 1-(meth)acryloyloxyalkyl-3-methylimidazolium bromide using inverse gas chromatography.

Activity coefficients at infinite dilution, gammainfinity, of organic compounds in two new room-temperature ionic liquids (n-methacryloyloxyhexyl-N-methylimidazolium bromide (C10H17O2MIM)(Br) at 313.15 and 323.15 K and n-acryloyloxypropyl-N-methylimidazolium bromide(C6H11O2MIM)(Br)) were determined using inverse gas chromatography. Phase loading studies of the net retention volume per gram of packing as a function of the percent phase loading were used to estimate the influence of concurrent retention mechanisms on the accuracy of activity coefficients at infinite dilution of solutes in both ionic liquids. It was found that most of the solutes were retained largely by partition with a small contribution from adsorption and that n-alkanes were retained predominantly by interfacial adsorption on ionic liquids studied in this work. The solvation characteristics of the two ionic liquids were evaluated using the Abraham solvation parameter model.

Partition coefficients of organic compounds in new imidazolium based ionic liquids using inverse gas chromatography

Partition coefficients of organic compounds in four ionic liquids: 1-ethanol-3-methylimidazolium tetrafluoroborate, 1-ethanol-3-methylimidazolium hexafluorophosphate, 1,3-dimethylimidazolium dimethylphosphate and 1-ethyl-3-methylimidazolium diethylphosphate were measured using inverse gas chromatography from 303.3 to 332.55K. The influence of gas-liquid and gas-solid interfacial adsorption of different solutes on ionic liquids was also studied. Most of the polar solutes were retained largely by partition while light hydrocarbons were retained predominantly by interfacial adsorption on the ionic liquids studied in this work. The solvation characteristics of the ionic liquids were evaluated using the Abraham solvation parameter model.

Phase Equilibria Measurements and Modeling of EPA and DHA Ethyl Esters in Supercritical Carbon Dioxide

Abstract A high pressure, variable-volume visual cell was used to perform static measurements of phase equilibria involving carbon dioxide and two different fatty acid ethyl esters: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl esters. Six temperatures ranging from 303.15 to 353.15 K were selected. In a second step, our data were compared with predictions obtained by two group contribution based models previously published. Both models are able to predict with quite high accuracy our data whatever the temperature.

Thermodynamic modeling for petroleum fluids I. Equation of state and group contribution for the estimation of thermodynamic parameters of heavy hydrocarbons

A group contribution method is proposed for estimating the critical properties and acentric factors of paraffins, naphtenes and aromatics with emphasis on extrapolating to very heavy compounds. Group contributions for sulfurized compounds were added to improve further applications in petroleum engineering or in any other domain. From the experimental normal boiling point, critical temperatures were correlated with a 0.6% average deviation on a set of 268 data and critical pressures with a 2.6% deviation on a 222 data set. The normal boiling points can be estimated without any experimental values. With this method, it was possible to correlate the normal boiling points of 641 hydrocarbons and sulfurized compounds with a deviation of less than 0.9%. From these estimated values, a 1% deviation was obtained at the critical temperatures and 2.8% at the critical pressures. The acentric factors of 160 compounds were correlated with a 6.5% deviation. With the proposed method, experimental vapor pressures were predicted using the Peng-Robinson equation of state for 125 compounds with a deviation of less than 5%. The results are compared with those obtained using other methods.

ADSORPTION AND DESORPTION OF M-XYLENE FROM SUPERCRITICAL CARBON DIOXIDE ON ACTIVATED CARBON

The equilibrium loadings of m-xylene from supercritical carbon dioxide on activated carbon are reported. The experimental data were obtained by measuring the outlet concentration of m-xylene eluted from a column packed with activated carbon until the effluent reached the input concentration. The Freundlich isotherm expression was found to correlate the experimental data satisfactorily. In a second step, the regeneration by supercritical carbon dioxide of activated carbon loaded with m-xylene was investigated. The experimental data demonstrated that the adsorptive capacities of the regenerated activated carbon for m-xylene after many cycles were close to those of the virgin carbon and remained stable. The effects of temperature, pressure, and flow rate on regeneration efficiency were also studied.

A new algorithm for enhanced oil recovery calculations

In order to test some algorithms currently available for enhanced oil recovery processes, the evolution of the thermodynamic Minimum Miscibility Pressure (MMP) with respect to the enrichment level of the injection gas by a solvent has been studied. Limitations of classical algorithms are evidenced and an alternative algorithm is proposed.

Thermodynamic modeling for petroleum fluids II. Prediction of PVT properties of oils and gases by fitting one or two parameters to the saturation pressures of reservoir fluids

This paper is devoted to the description of a method for modelling heavy cuts, using either a T.B.ce:simple-para. distillation or an advanced chromatography analysis method. Two sorts of reservoir fluids are defined depending on the advancement of the geochemical catagenetic reactions occurring during the history of the petroleum deposit. Given the existence of differences due to the geochemical history of fluids, two different thermodynamic characterizations may be computed from any given analytical information. One is generally more suitable for use with condensate gases and the other is more appropriate for calculating the physical properties of crude oils. The method presented here involves tuning one or two parameters to one of several saturation pressures of the reservoir fluid. This approach was tested on a data base including more than 50 reservoir fluids. In most cases, the PVT properties predicted using the above method were highly satisfactory.

Thermodynamic modeling for petroleum fluid III. Reservoir fluid saturation pressures. A complete PVT property estimation. Application to swelling test

Abstract This paper is the third one in a series in which a new strategy for modeling heavy petroleum cuts is proposed, with which the PVT properties of gas condensate and crude oils can be completely predicted using a classical one-fluid model with a cubic equation of state. In the second paper in this series, a new method of characterizing petroleum cuts was described. In was concluded that it was necessary to have at least one experimental saturation pressure in order to be able to calculate the PVT properties of a reservoir fluid with a good degree of accuracy. The third paper focuses on the development of a method which can be used to estimate the upper saturation pressure of reservoir fluids at about 100°C. The parameters used in the model were based on correlations involving more than 70 experimental saturation pressures. The method described in this paper, along with the characterization procedure described in the previous paper, makes it possible to completely calculate the PVT properties of a given reservoir fluid. Comparisons are made with other calculation methods described in the literature, and results obtained during gas injection experiments (swelling tests) are discussed.

A new approach in correlating the oil thermodynamic properties

A new compositional model is proposed to improve the prediction of phase behavior and physical properties of oil reservoir effluents. This work is based on a very classical and easy-to-handle cubic equation of state (EoS) coupled with a performing group contribution method devoted to the estimation of binary interaction parameters. The proposed model is compared to other published methods on the basis of laboratory data on real fluids, including pressure/volume/temperature (PVT) measurements and slim tube experiments. The method developed in this work shows enhanced results on a large range of pressure and temperature.