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Jeanphilippe Torre - One of the best experts on this subject based on the ideXlab platform.
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phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
The Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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new insights on gas hydroquinone Clathrates using in situ raman spectroscopy formation dissociation mechanisms kinetics and capture selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, Jeanphilippe TorreAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highli...
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revisiting the thermodynamic modelling of type i gas hydroquinone Clathrates
Physical Chemistry Chemical Physics, 2016Co-Authors: M.m. Conde, Jeanphilippe Torre, Christelle MiqueuAbstract:Under specific pressure and temperature conditions, certain gaseous species can be engaged in a host lattice of hydroquinone molecules, forming a supramolecular entity called a gas hydroquinone Clathrate. This study is devoted to the thermodynamic modelling of type I hydroquinone Clathrates. The gases considered in this work are argon, krypton, xenon, methane, nitrogen, oxygen and hydrogen sulphide. The basic van der Waals and Platteeuw model, which is, for example, not able to predict well the phase equilibrium properties of such Clathrates at high temperature, is modified and extended by considering first the solubility of the guest in solid HQ and then the mutual interactions between the gaseous molecules inside the Clathrate structure (i.e. guest–guest interactions). Other improvements of the basic theory, such as the choice of the reference state, are proposed, and a unique set of thermodynamic parameters valid for all the studied guests are finally calculated. Very good agreement is obtained between the model predictions and the experimental data available in the literature. Our results clearly demonstrate that the highest level of theory is necessary to describe well both the triphasic equilibrium line (where the HQ Clathrate, the native hydroquinone HQα and the gas coexist), the occupancy of the guest in the Clathrate, and the intercalation enthalpy.
R. Coupan - One of the best experts on this subject based on the ideXlab platform.
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Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
The Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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New Insights on Gas Hydroquinone Clathrates Using in Situ Raman Spectroscopy: Formation/Dissociation Mechanisms, Kinetics, and Capture Selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, J.-p. TorréAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highlighted the presence of a Clathrate structure with no guest molecules. We can therefore conclude that HQ Clathrate formation and dissociation are two-step reactions that pass through two distinct reaction intermediates: guest-loaded α-HQ and guest-free β-HQ. When an equimolar CO2/CH4 gas mixture is put in contact with either the α-HQ or the guest-free β-HQ, the CO2 is preferentially captured. Moreover, the guest-free β-HQ can retain the CO2 quicker and more selectively.
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new insights on gas hydroquinone Clathrates using in situ raman spectroscopy formation dissociation mechanisms kinetics and capture selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, Jeanphilippe TorreAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highli...
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Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
Journal of Chemical and Engineering Data, 2016Co-Authors: R. Coupan, M. Chabod, Christophe Dicharry, Joseph Diaz, Christelle Miqueu, J.-p. TorréAbstract:Hydroquinone (HQ) forms organic Clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, Clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2–HQ, CH4–HQ, and N2–HQ Clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium Clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the Clathrate occupancy with temperature. The equilibrium curves obtained for CO2–HQ and CH4–HQ Clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic Clathrates with potential impact on gas separation, energy storage, and transport.
Christophe Dicharry - One of the best experts on this subject based on the ideXlab platform.
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Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
The Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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New Insights on Gas Hydroquinone Clathrates Using in Situ Raman Spectroscopy: Formation/Dissociation Mechanisms, Kinetics, and Capture Selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, J.-p. TorréAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highlighted the presence of a Clathrate structure with no guest molecules. We can therefore conclude that HQ Clathrate formation and dissociation are two-step reactions that pass through two distinct reaction intermediates: guest-loaded α-HQ and guest-free β-HQ. When an equimolar CO2/CH4 gas mixture is put in contact with either the α-HQ or the guest-free β-HQ, the CO2 is preferentially captured. Moreover, the guest-free β-HQ can retain the CO2 quicker and more selectively.
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new insights on gas hydroquinone Clathrates using in situ raman spectroscopy formation dissociation mechanisms kinetics and capture selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, Jeanphilippe TorreAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highli...
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Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
Journal of Chemical and Engineering Data, 2016Co-Authors: R. Coupan, M. Chabod, Christophe Dicharry, Joseph Diaz, Christelle Miqueu, J.-p. TorréAbstract:Hydroquinone (HQ) forms organic Clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, Clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2–HQ, CH4–HQ, and N2–HQ Clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium Clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the Clathrate occupancy with temperature. The equilibrium curves obtained for CO2–HQ and CH4–HQ Clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic Clathrates with potential impact on gas separation, energy storage, and transport.
Christelle Miqueu - One of the best experts on this subject based on the ideXlab platform.
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phase equilibrium properties of co 2 ch 4 mixed gas hydroquinone Clathrates experimental data and model predictions
The Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Abstract Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO 2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO 2 /CH 4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO 2 /CH 4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH 4 molecules in the CO 2 /CH 4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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Phase equilibrium properties of CO 2 /CH 4 mixed gas hydroquinone Clathrates: Experimental data and model predictions
Journal of Chemical Thermodynamics, 2018Co-Authors: R. Coupan, Christophe Dicharry, Christelle Miqueu, Maria Martin Conde, Jeanphilippe TorreAbstract:Hydroquinone (HQ) Clathrates seem to be promising inclusion compounds for selective CO2 capture from gas mixtures. However, to date no phase equilibrium data are known in literature for mixed-gas HQ Clathrates. This study presents experimental equilibrium pressures obtained within a range of 298–343 K for different CO2/CH4 gas mixtures. The Clathrate composition is given for each equilibrium point. The capture selectivity is calculated from the molar composition of the CO2/CH4 gas mixture in the Clathrate and in the gas phase. The results obtained reveal that CH4 molecules in the CO2/CH4 mixtures are preferentially captured at equilibrium conditions. Our experimental data are compared against numerical predictions obtained from thermodynamic modeling using the Conde’s model. Very good agreement is found between the calculated and experimental data in terms of Clathrate phase equilibria.
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Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
Journal of Chemical and Engineering Data, 2016Co-Authors: R. Coupan, M. Chabod, Christophe Dicharry, Joseph Diaz, Christelle Miqueu, J.-p. TorréAbstract:Hydroquinone (HQ) forms organic Clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, Clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2–HQ, CH4–HQ, and N2–HQ Clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium Clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the Clathrate occupancy with temperature. The equilibrium curves obtained for CO2–HQ and CH4–HQ Clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic Clathrates with potential impact on gas separation, energy storage, and transport.
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revisiting the thermodynamic modelling of type i gas hydroquinone Clathrates
Physical Chemistry Chemical Physics, 2016Co-Authors: M.m. Conde, Jeanphilippe Torre, Christelle MiqueuAbstract:Under specific pressure and temperature conditions, certain gaseous species can be engaged in a host lattice of hydroquinone molecules, forming a supramolecular entity called a gas hydroquinone Clathrate. This study is devoted to the thermodynamic modelling of type I hydroquinone Clathrates. The gases considered in this work are argon, krypton, xenon, methane, nitrogen, oxygen and hydrogen sulphide. The basic van der Waals and Platteeuw model, which is, for example, not able to predict well the phase equilibrium properties of such Clathrates at high temperature, is modified and extended by considering first the solubility of the guest in solid HQ and then the mutual interactions between the gaseous molecules inside the Clathrate structure (i.e. guest–guest interactions). Other improvements of the basic theory, such as the choice of the reference state, are proposed, and a unique set of thermodynamic parameters valid for all the studied guests are finally calculated. Very good agreement is obtained between the model predictions and the experimental data available in the literature. Our results clearly demonstrate that the highest level of theory is necessary to describe well both the triphasic equilibrium line (where the HQ Clathrate, the native hydroquinone HQα and the gas coexist), the occupancy of the guest in the Clathrate, and the intercalation enthalpy.
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Revisiting the thermodynamic modelling of type I gas–hydroquinone Clathrates
Physical Chemistry Chemical Physics, 2016Co-Authors: M.m. Conde, J.-p. Torré, Christelle MiqueuAbstract:Under specific pressure and temperature conditions, certain gaseous species can be engaged in a host lattice of hydroquinone molecules, forming a supramolecular entity called a gas hydroquinone Clathrate. This study is devoted to the thermodynamic modelling of type I hydroquinone Clathrates. The gases considered in this work are argon, krypton, xenon, methane, nitrogen, oxygen and hydrogen sulphide. The basic van der Waals and Platteeuw model, which is, for example, not able to predict well the phase equilibrium properties of such Clathrates at high temperature, is modified and extended by considering first the solubility of the guest in solid HQ and then the mutual interactions between the gaseous molecules inside the Clathrate structure (i.e. guest–guest interactions). Other improvements of the basic theory, such as the choice of the reference state, are proposed, and a unique set of thermodynamic parameters valid for all the studied guests are finally calculated. Very good agreement is obtained between the model predictions and the experimental data available in the literature. Our results clearly demonstrate that the highest level of theory is necessary to describe well both the triphasic equilibrium line (where the HQ Clathrate, the native hydroquinone HQα and the gas coexist), the occupancy of the guest in the Clathrate, and the intercalation enthalpy.
J.-p. Torré - One of the best experts on this subject based on the ideXlab platform.
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New Insights on Gas Hydroquinone Clathrates Using in Situ Raman Spectroscopy: Formation/Dissociation Mechanisms, Kinetics, and Capture Selectivity
Journal of Physical Chemistry A, 2017Co-Authors: R. Coupan, Christophe Dicharry, Eve Pere, J.-p. TorréAbstract:Hydroquinone (HQ) is known to form organic Clathrates with different gaseous species over a wide range of pressures and temperatures. However, the enclathration reaction involving HQ is not fully understood. This work offers new elements of understanding HQ Clathrate formation and dissociation mechanisms. The kinetics and selectivity of the enclathration reaction were also investigated. The focus was placed on HQ Clathrates formed with CO2 and CH4 as guest molecules for potential use in practical applications for the separation of a CO2/CH4 gas mixture. The structural transition from the native form (α-HQ) to the Clathrate form (β-HQ), as well as the reverse process, were tracked using in situ Raman spectroscopy. The Clathrate formation was conducted at 323 K and 3.0 MPa, and the dissociation was conducted at 343 K and 1.0 kPa. The experiments with CH4 confirmed that a small amount of gas can fill the α-HQ before the phase transition from α- to β-HQ begins. The dissociation of the CO2–HQ Clathrates highlighted the presence of a Clathrate structure with no guest molecules. We can therefore conclude that HQ Clathrate formation and dissociation are two-step reactions that pass through two distinct reaction intermediates: guest-loaded α-HQ and guest-free β-HQ. When an equimolar CO2/CH4 gas mixture is put in contact with either the α-HQ or the guest-free β-HQ, the CO2 is preferentially captured. Moreover, the guest-free β-HQ can retain the CO2 quicker and more selectively.
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Experimental Determination of Phase Equilibria and Occupancies for CO2, CH4, and N2 Hydroquinone Clathrates
Journal of Chemical and Engineering Data, 2016Co-Authors: R. Coupan, M. Chabod, Christophe Dicharry, Joseph Diaz, Christelle Miqueu, J.-p. TorréAbstract:Hydroquinone (HQ) forms organic Clathrates in the presence of various gas molecules in specific thermodynamic conditions. For some systems, Clathrate phase equilibrium and occupancy data are very scarce or inexistent in literature to date. This work presents experimental results obtained for the CO2–HQ, CH4–HQ, and N2–HQ Clathrates, in an extended range of temperature from about 288 to 354 K. Formation/dissociation pressures, and occupancies at the equilibrium Clathrate forming conditions, were determined for these systems. Experiments showing the influence of the crystallization solvent, and the effect of the gas pressure on HQ solubility, were also presented and discussed. A good agreement is obtained between our experimental results and the already published experimental and modeling data. Our results show a clear dependency of the Clathrate occupancy with temperature. The equilibrium curves obtained for CO2–HQ and CH4–HQ Clathrates were found to be very close to each other. The results presented in this study, obtained in a relatively large temperature range, are new and important to the field of organic Clathrates with potential impact on gas separation, energy storage, and transport.
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Revisiting the thermodynamic modelling of type I gas–hydroquinone Clathrates
Physical Chemistry Chemical Physics, 2016Co-Authors: M.m. Conde, J.-p. Torré, Christelle MiqueuAbstract:Under specific pressure and temperature conditions, certain gaseous species can be engaged in a host lattice of hydroquinone molecules, forming a supramolecular entity called a gas hydroquinone Clathrate. This study is devoted to the thermodynamic modelling of type I hydroquinone Clathrates. The gases considered in this work are argon, krypton, xenon, methane, nitrogen, oxygen and hydrogen sulphide. The basic van der Waals and Platteeuw model, which is, for example, not able to predict well the phase equilibrium properties of such Clathrates at high temperature, is modified and extended by considering first the solubility of the guest in solid HQ and then the mutual interactions between the gaseous molecules inside the Clathrate structure (i.e. guest–guest interactions). Other improvements of the basic theory, such as the choice of the reference state, are proposed, and a unique set of thermodynamic parameters valid for all the studied guests are finally calculated. Very good agreement is obtained between the model predictions and the experimental data available in the literature. Our results clearly demonstrate that the highest level of theory is necessary to describe well both the triphasic equilibrium line (where the HQ Clathrate, the native hydroquinone HQα and the gas coexist), the occupancy of the guest in the Clathrate, and the intercalation enthalpy.
