Influence of chemical modifiers on the solubility of o- and m-hydroxybenzoic acid in supercritical carbon dioxide

Gurdial, Gurdev S.; Macnaughton, Stuart J.; Tomasko, David L.; Foster, Neil R.

doi:10.1021/ie00019a024

Cited by 99 publications

(57 citation statements)

References 27 publications

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“…For comparison with a real experiment, it is very important to allow for the non-asymptotic corrections to the power laws, Eqs. (7) and (8), in the range where more reliable data can be obtained. In the asymptotic region, it is very difficult to obtain reliable experimental data because of the effects of gravity and other experimental difficulties.…”

Section: Asymptotic and Nonasymptotic Scaling Behavior Of The Isochormentioning

confidence: 99%

“…For example, it is well-known that the addition of a polar co-solvent (methanol, for example) to a supercritical fluid (H 2 O or CO 2 ) often leads to an enhancement in the solubility of a solute and an improvement of the selectivity of the supercritical solvent (effective polar modifiers) [7][8][9][10][11]. Methanol has been often used as an effective modifier for H 2 O and CO 2 in supercritical fluid extraction and in supercritical chromatography.…”

Section: Introductionmentioning

confidence: 99%

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Isochoric Heat-Capacity Measurements for Pure Methanol in the Near-Critical and Supercritical Regions

et al. 2007

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Isochoric heat-capacity measurements for pure methanol are presented as a function of temperature at fixed densities between 136 and 750 kg·m −3 . The measurements cover a range of temperatures from 300 to 556 K. The coverage includes the one-and two-phase regions, the coexistence curve, the near-critical, and the supercritical regions. A high-temperature, high-pressure, adiabatic, and nearly constant-volume calorimeter was used for the measurements. Uncertainties of the heat-capacity measurements are estimated to be 2-3% depending on the experimental density and temperature. Temperatures at saturation, T S (ρ), for each measured density (isochore) were measured using a quasi-static thermogram technique. The uncertainty of the phase-transition temperature measurements is 0.02 K. The critical temperature and the critical density for pure methanol were extracted from the saturated data (T S , ρ S ) near the critical point. For one near-critical isochore (398.92 kg·m −3 ), the measurements were performed in both cooling and heating regimes to estimate the effect of thermal decomposition (chemical reaction) on the heat capacity and phase-transition properties of methanol. The measured values of C V and saturated densities (T S , ρ S ) for methanol were compared with values calculated from various multiparametric equations of state (EOS) (IUPAC, Bender-type, polynomial-type, and nonanalytical-type), scaling-type (crossover) EOS, and various correlations. The measured C V data have been analyzed and interpreted in terms of extended scaling equations for 163 0195-928X/07/0200-0163/0 © 2007 Springer Science+Business Media, LLC 164 Polikhronidi et al.the selected thermodynamic paths (critical isochore and coexistence curve) to accurately calculate the values of the asymptotical critical amplitudes (A ± 0 and B 0 ).

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Section: Asymptotic and Nonasymptotic Scaling Behavior Of The Isochormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Isochoric Heat-Capacity Measurements for Pure Methanol in the Near-Critical and Supercritical Regions

et al. 2007

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“…It is well known that the addition of a polar co-solvent (methanol, for example) to supercritical H 2 O or CO 2 often leads to an enhancement in the solubility of a solute and can improve the selectivity of a supercritical solvent (effective polar modifiers) [11][12][13][14][15][16][17][18]. Thus, Methanol is often used as an effective modifier for H 2 O and CO 2 in supercritical fluid extraction and in supercritical chromatography.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Properties of Methanol in the Critical and Supercritical Regions

et al. 2005

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The isochoric heat capacity of pure methanol in the temperature range from 482 to 533 K, at near-critical densities between 274.87 and 331.59 kg · m −3 , has been measured by using a high-temperature and high-pressure nearly constant volume adiabatic calorimeter. The measurements were performed in the singleand two-phase regions including along the coexistence curve. Uncertainties of the isochoric heat capacity measurements are estimated to be within 2%. The single-and two-phase isochoric heat capacities, temperatures, and densities at saturation were extracted from experimental data for each measured isochore. The critical temperature (T c = 512.78 ± 0.02 K) and the critical density (ρ c = 277.49 ± 2 kg · m −3 ) for pure methanol were derived from the isochoric heat-capacity measurements by using the well-established method of quasi-static thermograms. The results of the C V V T measurements together with recent new experimental PVT data for pure methanol were used to develop a thermodynamically self-consistent Helmholtz free-energy parametric crossover model, CREOS97-04. The accuracy of the crossover model was confirmed by a comprehensive comparison with available experimental data for pure methanol and values calculated with various multiparameter equations of state and correlations. In the critical and supercritical regions at 0.98T c T 1.5T c and in the density range 0.35ρ c ρ 1.65ρ c , CREOS97-04 represents all available experimental thermodynamic data for pure methanol to within their experimental uncertainties.

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“…The addition of a small amount of a volatile cosolvent to a supercritical fluid may dramatically increase the solute solubility. The solubility of salicylic acid in CO 2 at 55°C and 10 MPa is increased of 2 orders of magnitude by addition of 3.5% of methanol or acetone [48].…”

Section: Solute Solubilitymentioning

confidence: 99%

Thermodynamic Aspects of Supercritical Fluids Processing: Applications of Polymers and Wastes Treatment

Cansell

Rey

Beslin

1998

Rev. Inst. Fr. Pét.

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La mise en Ïuvre des fluides supercritiques est d'un intŽr•t croissant dans de nombreux domaines : pour la sŽparation (sŽparation et purification en pŽtrochimie, industrie alimentaire) et la chromatographie par fluides supercritiques (sŽparation analytique et prŽ-paratoire, dŽtermination des propriŽtŽs physicochimiques), comme milieux rŽactifs aux propriŽtŽs continžment ajustables allant du gaz au liquide (polyŽthyl•ne de faible densitŽ, Žlimination des dŽchets, recyclage des polym•res), en gŽologie et en minŽralogie (volcanologie, Žnergie gŽothermique, synth•se hydrothermique), dans la formation des particules, fibres et substrats (produits pharmaceutiques, explosifs, rev•tements), pour le sŽchage des matŽriaux (gels).Cet article prŽsente les propriŽtŽs physicochimiques exceptionnelles des fluides supercritiques en rapport avec leurs applications en ingŽnierie. Apr•s un bref rappel des concepts fondamentaux relatifs au comportement critique des fluides purs, nous dŽvelop-pons d'une mani•re plus dŽtaillŽe les propriŽtŽs physicochimiques ajustables des fluides dans le domaine supercritique. La deuxi•me partie de lÕarticle dŽcrit les applications en ingŽnierie des fluides supercritiques relatives aux rŽactions chimiques et au traitement des polym•res. Chaque prŽsentation d'application est divisŽe en deux parties : la premi•re rappelle les concepts de base et le contexte gŽnŽral ainsi que les propriŽtŽs physicochimiques, la seconde dŽveloppe les applications en ingŽnierie se rapportant au domaine concernŽ. THERMODYNAMIC ASPECTS OF SUPERCRITICAL FLUIDS PROCESSING: APPLICATIONS TO POLYMERS AND WASTES TREATMENTSupercritical fluid processes are of increasing interest for many fields: in supercritical fluid separation (petroleum-chemistry separation and purification, food industry) and supercritical fluid chromatography (analytical and preparative separation, determination of physicochemical properties); as reaction media with continuously adjustable properties from gas to liquid (lowdensity polyethylene, waste destruction, polymer recycling); in This paper presents the unusual physicochemical properties of supercritical fluids in relation to their engineering applications. After a short report of fundamental concepts of critical behavior in pure fluids, we develop in more details the tunable physicochemical properties of fluid in the supercritical domain. The second part of this paper describes the engineering applications of supercritical fluids relevant of chemical reactions and polymer processing. Each application presentation is divided in two parts: the first one recalls the basic concepts including general background, physicochemical properties and the second one develops the engineering applications relevant of the advocated domain. ASPECTOS TERMODINçMICOS DEL TRATAMIENTO DE LOS FLUIDOS SUPERCRêTICOS : APLICACIONES PARA LOS TRATAMIENTOS DE LOS POLêMEROS Y DE LOS RESIDUOSLa implementaci-n de los fluidos supercr'ticos presenta un interŽs cada vez mayor en numerosos campos : para la separaci-n (separaci-n y purific...

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Influence of chemical modifiers on the solubility of o- and m-hydroxybenzoic acid in supercritical carbon dioxide

Cited by 99 publications

References 27 publications

Isochoric Heat-Capacity Measurements for Pure Methanol in the Near-Critical and Supercritical Regions

Isochoric Heat-Capacity Measurements for Pure Methanol in the Near-Critical and Supercritical Regions

Thermodynamic Properties of Methanol in the Critical and Supercritical Regions

Thermodynamic Aspects of Supercritical Fluids Processing: Applications of Polymers and Wastes Treatment

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