Alain Valtz - Profile on Academia.edu (original) (raw)

Papers by Alain Valtz

Industrial & Engineering Chemistry Research, Mar 9, 2011

Hydrofluoroalkenes, like hexafluoropropylene, can be considered as new fluids for refrigeration s... more Hydrofluoroalkenes, like hexafluoropropylene, can be considered as new fluids for refrigeration systems, and consequently volumetric and critical property data are required. In this study a vibrating-tube densitometer technique was used to determine densities at 10 different temperatures between (263 and 362) K and pressures between (0.0009 and 10) MPa. The experimental uncertainties are (0.0005 MPa for pressure, (0.02 K for the temperature, and (0.05 % for vapor and liquid densities. Critical properties have been determined by direct measurement and utilization of experimental densities considering scaling laws. The Wagner, Span and Wagner, Peng-Robinson, and translated Peng-Robinson equations of state are used to correlate the data.

Experimental measurements and modelling of vapour−liquid equilibria for four mixtures of 2,3,3,3−tetrafluoropropene (R1234yf) with 1,1,1,2−tetrafluoroethane (R134a) or 1,1−difluoroethane (R152a) or trans−1−chloro−3,3,3−trifluoropropene (R1233zd(E)) or 2−chloro−3,3,3−trifluoropropene (R1233xf)

International Journal of Refrigeration

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Fluid Phase Equilibria

Journal of Chemical & Engineering Data, 2021

International Journal of Petroleum Technology, 2021

In this work, new isothermal experimental data of vapor-liquid equilibrium of the isobutane and e... more In this work, new isothermal experimental data of vapor-liquid equilibrium of the isobutane and ethyl mercaptan binary system are presented. The pressure and temperature conditions are up to 1 MPa and between 298 and 343K. The experimental apparatus is based on a “static-analytic method” specially developed for low-pressure measurements. Two online capillary samplers are used to take vapor and liquid samples that are analyzed with a gas chromatograph. The classical Peng Robinson Equation of State is used to correlate the experimental data. The van Ness test is used to check the consistency of the data. The measured data are also compared to predicted values from two predictive models, and a good agreement is found between the PSRK UNIFAC and the PPR78 models and the experimental measurements.

Journal of Chemical & Engineering Data, 2020

U min ()= 0.2 kg.m-3 U max ()= 8 kg.m-3 U min ()= 0.5 kg.m-3 U max ()= 15 kg.m-3 U min ()= 0... more U min ()= 0.2 kg.m-3 U max ()= 8 kg.m-3 U min ()= 0.5 kg.m-3 U max ()= 15 kg.m-3 U min ()= 0.4 kg.m-3 U max ()= 13 kg.m-3 U min ()= 0.1 kg.m-3 U max ()= 3 kg.m-3 U min ()= 0.1 kg.m-3 U max ()= 3 kg.m-3 U min ()= 0.1 kg.m-3 U max ()= 2 kg.m-3 U min ()= 0.2 kg.m-3 U max ()= 5 kg.m-3 U min ()= 0.1kg.m-3 U max ()= 2.5 kg.m-3 p/MPa /kg.m-3 p/MPa /kg.m-3 p/MPa /kg.m-3 p/MPa /kg.m-3  p/MPa /kg.m-3  p/MPa /kg.m-3  p/MPa /kg.m-3  p/MPa /kg.m-3 

Journal of Chemical & Engineering Data, 2020

The study presents p-T-x-y phase equilibria measurements of one solvent, chlorobenzene and one so... more The study presents p-T-x-y phase equilibria measurements of one solvent, chlorobenzene and one solute, hydrogen chloride. The technique of the equipment used is based on a "static-analytic" method that takes advantages of two capillary samplers linked to a gas chromatograph. Measurements were done at three temperatures (353.16, 403.16 and 453.25 K) and pressures from 0.6 up to 6.5 MPa. The experimental data measured were successfully correlated using the Peng Robinson Equation of state.

Fluid Phase Equilibria, 2019

Design of debutaniser in fractionation train in gas processing requires accurate knowledge of pha... more Design of debutaniser in fractionation train in gas processing requires accurate knowledge of phase equilibrium properties of n-butane with sulphur compounds like mercaptan. In this paper, we report high-quality isothermal vapor-liquid equilibrium data for n-butane + ethyl mercaptan (or ethanethiol) between 298.14 K to 388.18 K and pressures up to 2.0029 MPa. An equipment whose experimental technique is based on static-analytic method was considered. The equipment is composed by an agitated equilibrium cell with two online micro samplers connected to a Gas Chromatograph. The data was correlated with the Peng Robinson equation of state with classical alpha function. A comparison was also performed with two predictive models, PPR78 and PSRK UNIFAC.

Journal of Chemical & Engineering Data, 2018

Air contains impurities, which must be removed before its transformation and utilization. In the ... more Air contains impurities, which must be removed before its transformation and utilization. In the present work, new isothermal Vapor-Liquid Equilibrium (VLE) data are reported for three binary systems containing NO with (CO, N2 or Ar) at different temperatures (between 105 and 146 K) and pressures up to 4 MPa. The compositions of the coexisting phases were experimentally determined using an apparatus based on the "static-analytic" method. The Peng-Robinson Equation of State combined with different mixing rules (classical, Wong-Sandler and Huron-Vidal) were used to represent the phase diagram (P, x, y).

International Journal of Refrigeration, 2019

Isothermal vapour-liquid equilibrium (VLE) of the R-1234yf + R-245cb binary system were measured ... more Isothermal vapour-liquid equilibrium (VLE) of the R-1234yf + R-245cb binary system were measured using a "static-analytic" apparatus at temperatures from 283.39 to 343.27 K. The data measured were compared with literature data for conformity checking. Albeit both VLE measurement sets are in good accordance, an unexpected behaviour was observed for the relative volatility calculated on the basis of the literature data. The thermodynamic model used for the calculations reproduces very well R-1234yf + R-245cb VLE data, and is based on a 3-parameter cubic equation of state (denoted by NEoS). This cubic equation of state was associated with the Mathias-Copeman alpha function and van der Waals mixing rules. Comparisons were also done with Peng Robinson EoS with similar alpha function and mixing rules.

Journal of Natural Gas Engineering, 2019

This work reports high-quality isothermal vapor-liquid equilibrium data for ethane + ethanethiol ... more This work reports high-quality isothermal vapor-liquid equilibrium data for ethane + ethanethiol (or ethyl mercaptan) at 303 K, 323 K and 343 K and pressures up to 6.25 MPa. A sapphire-tube equilibrium cell with an online micro sampler and GC-TCD are employed to measure equilibrium phase concentrations at specific temperatures and pressures. Peng Robinson equation of state with classical alpha function is found adequate for data treatment and thermodynamic modelling.

Fluid Phase Equilibria, 2016

From the development of sour reserves and acid gas injection into oil reservoirs to the impact of... more From the development of sour reserves and acid gas injection into oil reservoirs to the impact of hydrogen sulfide in CCS scheme, knowledge of the phase behaviour and thermophysical properties of the hydrogen sulfide + carbon dioxide is essential. Due to the toxicity of CO 2 -H 2 S system, there are few experimental data available in the literature. The aim of this work is to investigate the densities and thermodynamic properties of acid gases and liquids. Densities of the 95.05 mol% CO 2 + 4.95 mol% H 2 S binary system were measured continuously using a high temperature and pressure Vibrating Tube Densitometer (VTD), Anton Paar DMA 512 at pressures up to 41 MPa at five different temperatures, 273, 283, 298, 323 and 353 K in gas, liquid and supercritical regions. The specific heat capacity, compressibility factor, dew point and bubble point of the system have also been derived from the measured density data. The experimental data then were employed to evaluate the GERG-2008 equations of state and classical cubic equations of state (PR, SRK and VPT) with a CO 2 volume correction model as well as volume translation.

Fluid Phase Equilibria, 2014

Thermodynamic behavior of the CO2+SO2 mixture: Experimental and Monte Carlo simulation studies

Energy Procedia, 2009

Fluid Phase Equilibria, 2014

We determine new experimental data concerning CO 2 + SO 2 , CO 2 + NO binary systems and CO 2 + O... more We determine new experimental data concerning CO 2 + SO 2 , CO 2 + NO binary systems and CO 2 + O 2 + Ar, CO 2 + SO 2 + O 2 Ternary systems An equipment based on "static analytic" method with phase sampling. Cubic equation of state is used for the data treatment. Data and model are used to generate complete phase diagram of the different systems CO 2 capture transportation and storage, or CO 2 capture transportation and utilization, are two ways which should be considered in the industry in order to reduce the emission of CO 2 . After capture, CO 2 is not pure and contain impurities like SO 2 , NOx, N 2 , O 2 and Ar for example. Two binary systems involving CO 2 were studied in this work (CO 2 + SO 2 at 263.15 and A C C E P T E D M A N U S C R I P T 333.21 K and between 0.1 and 8.8 MPa and CO 2 + NO in at 232.93, 252.98 and 273.15 K, and between 1 and 11.5 MPa ) and two ternary systems (CO 2 + O 2 + Ar and CO 2 + SO 2 + O 2 (expected composition (0.94/0.03/0.03 mole fractions)) at 253, 273 and 293 K, between 1.9 and 7.6 MPa) were also studied experimentally. The equipment used is based on "staticanalytic" method, taking advantage of two capillary samplers (Rolsi™, Armines' patent). The classical Peng-Robinson equation of state is used to represent the isothermal P, x, y data..

Journal of Chemical & Engineering Data, 2003

Isothermal vapor-liquid equilibrium data for the Difluoromethane (R32) + Propane binary system ar... more Isothermal vapor-liquid equilibrium data for the Difluoromethane (R32) + Propane binary system are presented at 278.10, 294.83, 303.23, 313.26 and 343.26 K and pressures up to 5.4 MPa. The experimental method is the static-analytic type. It takes advantage of mobile pneumatic capillary samplers (Rolsi™, Armines' patent) developed in our laboratory. At a fixed temperature the azeotrope vapor pressure is larger then those of the pure component. The particularity of R32-Propane azeotropic binary system is to present in two critical point over the critical temperature if the azeotrope. This particular behavior has been proved and even shown visually by means of two supplementary experiments with equipment based on the static-synthetic method involving a variable volume cell. Data along the five isotherms have been represented with the Soave-Redlich-Kwong (SRK) equation of state and MHV1 mixing rules involving the NRTL model. We have calculated the location of the azeotrope using the equality of Equation of State attractive parameter between the two phases.

Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State

Industrial & Engineering Chemistry Research, 2011

... Modeling In a previous paper,(3) we used the Peng−Robinson equation of state (PR EoS)(13) wit... more ... Modeling In a previous paper,(3) we used the Peng−Robinson equation of state (PR EoS)(13) with the Mathias−Copeman (MC)(14) alpha function to correlate the vapor pressure and the densities of HFP. ... That is why, in this work, it is specified Landau-crossover. ...

Reply to “Comments on ‘Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State’”

Industrial & Engineering Chemistry Research, 2011

En référence à 1) Comments on "Experimental Measurement of Vapor Pressures and Densities at ... more En référence à 1) Comments on "Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State" Author(s): Laugier, Serge; Richon, Dominique Source: INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH Volume: 50 Issue: 15 Special Issue: SI Pages: 9473-9475 DOI: 10.1021/ie2011559 Published: AUG 3 2011 2) Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State Author(s): Dicko, Moussa; Belaribi-Boukais, Ghemina; Coquelet, Christophe; Valtz, Alain; Belaribi, Farid Brahim; Naidoo, Paramespri; Ramjugernath, Deresh Source: INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH Volume: 50 Issue: 8 Pages: 4761-4768 DOI: 10.1021/ie102354p Published: APR 20 2011International audienc

Industrial & Engineering Chemistry Research, Mar 9, 2011

International Journal of Refrigeration

Fluid Phase Equilibria

Journal of Chemical & Engineering Data, 2021

International Journal of Petroleum Technology, 2021

Journal of Chemical & Engineering Data, 2020

Fluid Phase Equilibria, 2019

Journal of Chemical & Engineering Data, 2018

International Journal of Refrigeration, 2019

Journal of Natural Gas Engineering, 2019

Fluid Phase Equilibria, 2016

Fluid Phase Equilibria, 2014

Thermodynamic behavior of the CO2+SO2 mixture: Experimental and Monte Carlo simulation studies

Energy Procedia, 2009

Fluid Phase Equilibria, 2014

Journal of Chemical & Engineering Data, 2003

Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State

Industrial & Engineering Chemistry Research, 2011

Reply to “Comments on ‘Experimental Measurement of Vapor Pressures and Densities at Saturation of Pure Hexafluoropropylene Oxide: Modeling Using a Crossover Equation of State’”

Industrial & Engineering Chemistry Research, 2011