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A high-pressure-cell technique based on the analytical method was used to investigate the simultaneous solubility of the chemically reacting gases ammonia and carbon dioxide in solvent mixtures of (water + methanol). Seven (gas-free) solvent compositions were considered (methanol mole fractions of about 0, 0.05, 0.25, 0.5, 0.75, 0.95, and 1). The temperatures were approximately (313, 353, and 393) K. In the isothermal experimental series, carbon dioxide was added stepwise to a cell containing a mixture of (water + methanol + ammonia). The stoichiometric molality of ammonia in the solvent mixture of (water + methanol) was approximately (6 and 12) mol·(kg of solvent mixture)−1. The carbon dioxide loading (i.e., the ratio of the stoichiometric molalities of carbon dioxide and ammonia) ranged up to 1.07. The total pressure ranged up to 5.5 MPa. Vapor−liquid equilibrium data, including partial pressures of all components, are reported. [ABSTRACT FROM AUTHOR]

The correlation and prediction of the solubility of gases in (nonelectrolyte as well as in electrolyte) aqueous/organic solvent mixtures is an important topic in many areas of chemical engineering. Despite the importance of that field, comparatively little attention has been given to that area in both classical thermodynamics (i.e., correlation methods that are based on semiempirical expressions for the excess Gibbs energy) and molecular simulation (where gas solubility can be predicted from intermolecular pair potentials). In the work presented here, recently published experimental data for the solubility of carbon dioxide in aqueous solutions of acetone (covering temperatures from 313 to 395 K at pressures ranging up to about 9 MPa) are used for testing a semiempirical, classical method (for the correlation of such gas solubility phenomena) as well as the Gibbs ensemble Monte Carlo method (GEMC) (for predicting the solubility of carbon dioxide in aqueous solutions of acetone from published intermolecular pair potentials without using any adjustable binary interaction parameter). The correlation method reproduces the experimental data (nearly) within experimental uncertainty, as was expected. The predictions by the GEMC method also agree well with the experimental data. [ABSTRACT FROM AUTHOR]

Experimental data for the solubility of the two single gases carbon monoxide and oxygen in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]) are reported for temperatures between (293.25 and 413.2) K. The maximum pressure (the maximum gas molality) was 9.8 MPa (0.27 mol·kg−1) for carbon monoxide and 9.1 MPa (0.31 mol·kg−1) for oxygen. The experiments were performed using a high-pressure view-cell technique operating on the synthetic method. Oxygen shows a slightly higher solubility than carbon monoxide under all conditions investigated, but the solubility generally remains very low. Both gases become less soluble in [hmim][Tf2N] with increasing temperature; however, the effect is not very pronounced and becomes ambiguous for carbon monoxide above 373 K. An extension of Henry’s law is employed in correlating the solubility pressures. The final results for the Henry’s constant (at zero pressure) of carbon monoxide and oxygen in [hmim][Tf2N] (on the molality scale) are represented within the experimental uncertainty (1 % for both gases) by ln(kH,CO(0)/MPa) = 5.3954 − 364.2/(T/K) − 0.002356 (T/K) and ln(kH,O2(0)/MPa) = 5.7618 − 505.1/(T/K) − 0.002802 (T/K), respectively. [ABSTRACT FROM AUTHOR]

Experimental results for the solubility of tetrafluoromethane (CF4, R14) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (hmimTf2N) are presented for temperatures between 293.3 and 413.3 K, at pressures (gas molalities) up to 9.6 MPa (0.22 mol kg-1). The experimental results were determined with a high-pressure view-cell technique operating on the synthetic method. The experimental data were used to determine Henry's constant of tetrafluoromethane in hmimTf2N. The results for the Henry's constant (at zero pressure) are correlated (on the molality scale) within the experimental uncertainty (i.e., about 1.1%) by ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%CF%@sb@%4%@sbx@%%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 7.537 − 893.8/(T/K) − 0.003977(T/K). Henry's law was also extended to describe the gas solubility at higher pressures. Furthermore, a cubic equation of state was used to correlate the gas solubility over the entire range of experimentally investigated temperature and pressure. Both methods proved suited for a reliable correlation of the new experimental data. [ABSTRACT FROM AUTHOR]

This work reports new experimental results for the solubility of two single gases (methane and xenon) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (hmimTf2N). The solubility was measured with a high-pressure view-cell technique operating on the synthetic method. The temperature ranged from 293.3 to 413.3 K, and the maximum pressure (the maximum gas molality) was 9.3 MPa (0.51 mol·kg-1) for methane and 9.6 MPa (2.08 mol·kg-1) for xenon. Xenon shows a significantly higher solubility than methane at all conditions investigated. Both gases become less soluble in hmimTf2N with rising temperature. An extension of Henry's law is employed to correlate the solubility pressures. The final results for the Henry's constants (at zero pressure) of methane and xenon in hmimTf2N (on the molality scale) are represented within the experimental uncertainty (about 1.2% for methane and 1% for xenon) by ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%CH%@sb@%4%@sbx@%%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 6.4929 − 835.9/(T/K) − 0.003471(T/K) and ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%Xe%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 6.3357 − 1321.4/(T/K) − 0.00265(T/K), respectively. [ABSTRACT FROM AUTHOR]

Solubility measurements of methane and of xenon in the ionic liquid 1-n-butyl-3-methylimidazolium methyl sulfate (bmimCH3SO4) were performed with a high-pressure view-cell technique based on the synthetic method. The temperature ranged from 293.1 K to 413.2 K, and the maximum pressure (the maximum gas molality) was 8.9 MPa (0.19 mol·kg-1) for methane and 11.3 MPa (0.65 mol·kg-1) for xenon. Both gases become less soluble in bmimCH3SO4with rising temperature, but xenon shows a significantly higher solubility at all conditions investigated. An extension of Henry's law is employed to correlate the solubility pressures in both cases. The final results for the Henry's constant (at zero pressure) of methane and xenon in bmimCH3SO4(on the molality scale) are correlated within the experimental uncertainty (about ± 1.3 %) by ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%CH%@sb@%4%@sbx@%%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 6.216 − 564.5/(T/K) − 0.002566(T/K) and ln(%@mt;sys@%%@ital@%k%@rsf@%%@sx@%H,%@/hd@%Xe%@be@%%@/hd@%%@fn;(;vis;full;auto@%0%@fnx;);vis;full@%%@/hd@%%@sxx@%%@mx@%/MPa) 5.5906 − 928/(T/K) − 0.00141(T/K), respectively. [ABSTRACT FROM AUTHOR]

New experimental results are presented for the solubility of carbon dioxide in pure liquid acetone 2-propanone, (CH3)2CO and in solvent mixtures of (acetone water) at gas-free solvent mixture acetone mole fractions of about (0.05, 0.1, 0.25, 0.5, 0.75, 0.9, and 0.95), temperatures of (313.75, 354.35, and 395.0) K, and total pressures up to about 10 MPa. Numerical values are reported for the (molality scale based) Henry's constant of CO2in acetone and in (acetone water) at vanishing amount of the gas in the liquid mixture resulting from the new experimental data by applying the well-known extrapolation procedure. The experimental work is to provide a database for developing and testing thermodynamic models to describe the gas solubility in salt-free and salt-containing mixed solvents as well as to test screening methods based, for example, on molecular simulation. [ABSTRACT FROM AUTHOR]

A high-pressure view-cell technique based on the synthetic method was used to determine the total pressure above aqueous solutions of two single salts (potassium chloride and potassium carbonate) and carbon dioxide. In the series of measurements with potassium chloride, the molality of the salt amounted to about (2 and 4) mol·(kg of water)-1, the temperature ranged from about (313 to 433) K, and the molality of carbon dioxide ranged up to about 1 mol·(kg of water)-1, corresponding to a maximum pressure of about 9.4 MPa. In the series of measurements with potassium carbonate, the stoichiometric molality of that salt amounted to about (0.43 and 1.7) mol·(kg of water)-1(stoichiometric mass fraction of the salt of about 0.056 and 0.19, respectively), the temperature ranged from about (313 to 393) K, and the ratio of the stoichiometric molalities of carbon dioxide to potassium carbonate ranged from about 0.7 to 3.6, corresponding to pressures from about (0.27 to 9.2) MPa. The vapor−liquid equilibrium of the systems (CO2KCl H2O) and (CO2K2CO3H2O) (the latter allowing for the precipitation of KHCO3that is important in connection with the “Hot Potassium Carbonate (Benfield) Process” and its modifications by activating additives) is described by means of a thermodynamic model based on Pitzer's molality scale based equation for the Gibbs excess energy of the aqueous phase. Model parameters are determined from the new carbon dioxide solubility data as well as from an extensive database adopted from the literature. [ABSTRACT FROM AUTHOR]

Experimental data for the solubility of the two single gases carbon dioxide and hydrogen in the ionic liquid 1-n-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([bmpy][Tf2N]) are reported for temperatures between (293.1 and 413.2) K. The maximum pressure (the maximum gas molality in the solvent) was 10.8 MPa (4.43 mol·kg−1) for carbon dioxide and 8.9 MPa (0.14 mol·kg−1) for hydrogen. The experiments were performed using a high-pressure view-cell technique operating on the synthetic method. The solubility of carbon dioxide in [bmpy][Tf2N] is more than 1 order of magnitude higher than the solubility of hydrogen. Carbon dioxide becomes less soluble in [bmpy][Tf2N] with increasing temperature, whereas hydrogen shows the opposite effect. An extension of Henry’s law is employed to correlate the solubility pressures. The final results for the Henry’s constant (at zero pressure) of carbon dioxide and hydrogen in [bmpy][Tf2N] (on the molality scale) are represented within the experimental uncertainty (about 0.8 % for carbon dioxide and 1.3 % for hydrogen) by ln(kH,CO2(0)/MPa) = 8.5128 − 2057/(T/K) − 0.004274·(T/K) and ln(kH, H2(0)/MPa) = 3.5746 + 343/(T/K) − 0.0008·(T/K), respectively. [ABSTRACT FROM AUTHOR]

New experimental results are reported for the influence of two single salts (sodium chloride and sodium sulfate) on the solubility of ammonia in liquid mixtures of water and methanol at 353 and 393 K. The mole fractions of methanol in the (gas-free and salt-free) solvent mixture of water and methanol were about 0.25, 0.5, and 0.75 in the experiments with sodium chloride and about 0.05 and 0.25 in the experiments with sodium sulfate. The molality of the salt varied between about 0.25 and 2 (0.15 and 1) mol/kg of the solvent mixture in the systems with sodium chloride (sodium sulfate). The maximum molality of ammonia was about 6.7 mol/kg of (water + methanol) for both temperatures and for both salts. The maximum total pressure above the liquid solutions was about 0.3 MPa (1 MPa) in the system containing sodium chloride at 353 K (393 K) and about 0.2 MPa (0.7 MPa) in the system with sodium sulfate at 353 K (393 K). The experimental results are used to test a thermodynamic framework which allows the influence of both single strong electrolytes on the solubility of ammonia in liquid mixtures of water and methanol to be predicted. The prediction results are in good agreement with the new experimental data. [ABSTRACT FROM AUTHOR]

A high-pressure view-cell technique based on the synthetic method was used to determine the solubility of ammonia in liquid methanol (total pressure at a preset temperature and liquid-phase composition). The solubility pressure ranges up to about 4.2 MPa. The temperature amounts to (313.75, 354.35, and 395.0) K. The molality of ammonia in methanol (the mole fraction of ammonia in the liquid) ranges up to about 66.4 mol·kg-1(about 0.68). Furthermore, a high-pressure cell technique based on the analytical method was used to investigate the vapor−liquid equilibrium of that same system (equilibrium pressure as well as liquid- and gas-phase compositions at a preset temperature). The solubility pressure ranges up to about 1.6 MPa. The temperature amounts to (353.1 and 393.1) K. The molality of ammonia in methanol (the mole fraction of ammonia in the liquid) ranges up to 13 mol·kg-1(about 0.3). The experimental results are used to determine Henry's constant of ammonia in methanol. Furthermore, the experimental data are correlated by applying Pitzer's molality scale based equation for the Gibbs excess energy. [ABSTRACT FROM AUTHOR]