Browsing by Author "de la Fuente, Juan C."

Now showing 1 - 8 of 8
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    Correlation for the variations with temperature of solute solubilities in high temperature water
    (ELSEVIER, 2011) del Valle, Jose M.; de la Fuente, Juan C.; Srinivas, Keerthi; King, Jerry W.
    Methods for estimating solute solubilities in high temperature water both below and above its boiling point (under pressure) are needed for applications of this medium in processing applications such as sub-critical water extraction, reaction chemistry in heated water, and in the material sciences. There is a paucity of data and correlative methods for estimating solute solubilities under these conditions; the limited existing methods are based on a limited solubility data base, and in some cases predicted solubility values are in quite serious disagreement with experimentally derived data. Here available solute solubility data both above and below the boiling point of water has been correlated for diverse solute types consisting of hydrocarbons, essential oil components, pesticides, polyphenolic compounds, as well as solutes exhibiting high solubility in water under the stated conditions. Utilizing solubility data from diverse sources, appropriate conversions and equations have been derived for converting all solubility data to a mole fraction basis, while the other required physicochemical parameters, such as melting point, boiling point, critical properties, have been estimated, when necessary, largely by group contribution-based methods. A solubility model based on such physicochemical parameters and critical properties of the solutes was derived. An excellent correlation is obtained for x(c)(estimated) versus x(c) using this approach and the prediction of solute solubility in water as a function of temperature was found to be excellent for 431 data points representing the solubility of 34 solutes in the temperature range between 298 and 573 K. (C) 2010 Elsevier B.V. All rights reserved.
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    Effect of triolein addition on the solubility of capsanthin in supercritical carbon dioxide
    (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2012) Araus, Karina A.; del Valle, Jose M.; Robert, Paz S.; de la Fuente, Juan C.
    This manuscript presents new phase equilibrium data for capsanthin in pure and triolein-entrained Supercritical (SC) carbon dioxide (CO2). The aim of the work was to determine the cosolvent effect of triolein on capsanthin by comparing solubility results in a ternary (CO2 + triolein + capsanthin) system and binary (CO2 + capsanthin) system at (313 or 333) K and (19 to 34) MPa. For this, authors isolated capsanthin from red pepper (Capsicum annuum L.) and tested it using a dynamic-analytical method in an apparatus with recirculation and online analysis of the CO2-rich phase. Within the experimental region, the solubility of capsanthin in pure SC-CO2 increased with system temperature at isobaric conditions and also increased with pressure at isothermal conditions. Solubilities ranged from a minimal of 0.65 mu mol/mol at 313 K and 19 MPa to a maximal of 1.97 mu mol/mol at 333 K and 32 MPa. The concentration of triolein in the ternary system was equivalent to that its solubility in pure SC-CO2 depending on system temperature and pressure conditions. Crossover pressure was determined experimentally at 29.6 MPa, below which solubility of triolein decreased with temperature (effect of density). Above the crossover pressure, solubility of triolein increased with temperature (vapor pressure effect). Values of solubility within this range were 0.16 mmol/mol at 19 MPa and 313 K to 0.41 mmol/mol at 33 MPa and 333 K. Independent of system temperature and pressure, capsanthin solubility in triolein-entrained SC-CO2 increased by a factor of about 3 (triolein-induced enhancement factor) as compared to its solubility in pure CO2, under similar conditions of pressure and temperature. The maximal solubility of capsanthin in SC-CO2 experimentally observed in this study was 5.27 mu mol/mol at 333 K and 33 MPa in the presence of 4.10 mmol/mol triolein. (C) 2012 Elsevier Ltd. All rights reserved.
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    Experimental solubility data of two solid derivatives of menadione in supercritical carbon dioxide : 2-((4-chlorobenzyl)amino)-3-methylnaphtalene-1,4-dione, and 2-((4-chlorophenethyl)amino)-3-methylnaphtalene-1,4-dione
    (2020) Zacconi, Flavia C. M.; Cabrera, Alejandro Leopoldo; Lozada Jerez Jose Alejandro; Del Valle Lladser Jose Manuel; de la Fuente, Juan C.
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    Solubilities in Supercritical Carbon Dioxide of (2E,6E)-3,7,11-Trimethyldodeca-2,6,10-trien-1-ol (Farnesol) and (2S)-5,7-Dihydroxy-2-(4-hydroxyphenyl)chroman-4-one (Naringenin)
    (AMER CHEMICAL SOC, 2010) Nunez, Gonzalo A.; del Valle, Jose M.; de la Fuente, Juan C.
    We measured the solubility in supercritical carbon dioxide (CO2) of farnesol [(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-ol] and naringenin [(2S)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one] using a static-analytic method (a high-pressure static equilibrium cell coupled to an HPLC). The molar fraction of farnesol in the saturated CO2-rich phase increased between y(2) = 0.13.10(-3) at 333 K and 11.4 MPa to y(2) = 1.91.10(-5) at 333 K and 26.0 MPa for farnesol and from y(2) = 0.49.10(-5) at 313 K and 10.3 MPa to y(2) = 1.65.10(-5) at 333 K and 44.5 MPa for naringenin. The average error of our measurements was about 25 To. Farnesol had an end-temperature crossover point at approximately 17 MPa, whereas naringenin exhibited a monotonous increase in solubility with both temperature and pressure. The differences in solubility between farnesol, naringenin, and other sesquisterpenes or flavonoids reported in the literature were partially explained by differences in molecular weight and polarity between solutes. We correlated experimental data as a function of the system temperature and pressure and the density of the solvent using a literature model that also showed the autoconsistency of the data for CO2 densities above 412 kg.m(-3) for naringenin.
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    Solubility of 1,3-Dimethyl-7H-purine-2,6-dione (Theophylline) in Supercritical Carbon Dioxide
    (AMER CHEMICAL SOC, 2009) de la Fuente, Juan C.; Nunez, Gonzalo; del Valle, Jose M.
    This contribution provides complementary experimental data of solubility (y(2), molar fraction) of solid 1,3-dimethyl-7H-purine-2,6-dione (theophylline) in supercritical CO2 as a function of temperature (313 K <= T <= 333 K) and pressure (10 MPa <= P <= 44 MPa). A static-analytic methodology was used with standard deviations from average solubility measurements of <= 38% and with estimated inherit errors <= 25%. The solubility of theophylline increased with the CO2 density from 0.33.10(-5) mol.mol(-1) at 797.2 kg.m(-3) (313 K, 16 MPa) to 3.3.10(-5) mol.mol(-1) at 890.2 kg.m(-3) (333 K, 40 MPa). The solubility increased with pressure and temperature. Experimental solubilities were correlated with a density-based model with three adjustable parameters, which was valid for solvent densities in the range of (400 to 950) kg.m(-3).
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    Solubility of beta-carotene in ethanol- and triolein-modified CO2
    (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2011) Araus, Karina A.; Canales, Roberto I.; del Valle, Jose M.; de la Fuente, Juan C.
    Modification of an experimental device and methodology improved speed and reproducibility of measurement of solubility of beta-carotene in pure and modified SuperCritical (SC) CO2 at (313 to 333) K. Solubilities of beta-carotene in pure CO2 at (17 to 34) MPa ranged (0.17 to 1.06) mu mol/mol and agreed with values reported in literature. The solubility of beta-carotene in CO2 modified with (1.2 to 1.6) % mol ethanol increased by a factor of 1.7 to 3.0 as compared to its solubility in pure CO2 under equivalent conditions. The concentration of triolein in equilibrated ternary (CO2 + beta-carotene + triolein) mixtures having excess triolein reached values (0.01 to 0.39) mmol/mol corresponding to its solubility in pure SC CO2 under equivalent conditions. Under these conditions, the solubility of beta-carotene in triolein-modified CO2 increased by a factor of up to 4.0 in relation with its solubility in pure CO2 at comparable system temperature and pressure, reaching an uppermost value of 3.3 mu mol/mol at 333 K and 32 MPa. Unlike in the case of ethanol, where enhancements in solubility where relatively independent on system conditions, solubility enhancements using triolein as co-solvent increased markedly with system pressure, being larger than using (1.2 to 1.6)% mol ethanol at about (24 to 28) MPa, depending on system temperature. The increase in the solubility beta-carotene in SC CO2 as a result of using ethanol or triolein as co-solvent apparently does not depend on the increase in density associated with the dissolution of the co-solvent in CO2. Enhancements may be due to an increase in the polarizability of SC CO2, which possibly growths markedly as triolein dissolves in it when the system pressure becomes higher. (C) 2011 Elsevier Ltd. All rights reserved.
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    Solubility of carotenoid pigments (lycopene and astaxanthin) in supercritical carbon dioxide
    (ELSEVIER SCIENCE BV, 2006) de la Fuente, Juan C.; Oyarzun, Bernardo; Quezada, Nathalie; del Valle, Jose M.
    This contribution provides basic data for developing an extraction process for carotenoid compounds in terrestrial and marine plants with supercritical CO2 (SC-CO2). Specifically, the solubility (y(2), molar fraction) of lycopene and astaxanthin was measured in SC-CO2 as a function of temperature (313 K <= T <= 333 K) and pressure (10 MPa <= P <= 42 MPa). Experimental data were correlated using a density-based model valid for a solvent density above 330kg/m3. Based on this model and the best-fit model parameters, the solubility of lycopene in SC-CO2 at 313 K and 30 MPa (y(2) = 0.40 x 10(-6)) was within a wide range of experimental values for the solubility of beta-carotene in CO2 under same conditions (0.20 x 10(-6) <= y(2) <= 0.50 x 10-6). The interpolated solubility of astaxanthin in SC-CO2 at 313 K and 30 MPa was slightly smaller (y(2) = 0.19 x 10(-6)) than the one of lycopene, as expected for a slightly heavier and more polar solute. There was a larger increase in solubility of both lycopene and astaxanthin by increasing the temperature from 313 to 333 K at a constant pressure of 30 MPa (2.8-5.1 times) than by increasing the pressure from 30 to 50 MPa at a constant temperature of 313 K (1.3-1.6 times), which was consistent with the trend in literature for the solubility of beta-carotene in SC-CO2. (c) 2006 Elsevier B.V. All rights reserved.
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    Supplementary vapor pressure data of the glycol ethers, 1-methoxy-2-propanol, and 2-methoxyethanol at a pressure range of (15 to 177) kPa
    (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2012) Bejarano, Arturo; Poveda, Laura J.; de la Fuente, Juan C.
    The vapor pressure of pure 1-methoxy-2-propanol and 2-methoxyethanol, commonly used as co-solvents in inks, paints, coatings, organic/water solutions among many other applications, were measured with a dynamic recirculation apparatus at a pressure range of (15 to 177) kPa. The measurements were performed at temperature ranges of (342 to 412) K for 1-methoxy-2-propanol and (346 to 417) K for 2-methoxyethanol. The maximum likelihood method was used to estimate the parameters of the Antoine equation, the parameters of an extended Antoine equation and the Wagner equation were determined by non linear least squares method. The three models showed root mean square deviations (rmsd) of 0.39%, 0.38%, and 0.29%, and 0.37%, 0.33%, and 0.32%, for 1-methoxy-2-propanol and 2-methoxyethanol, respectively. Additionally, the experimental data and correlation were compared with those available in the literature. (C) 2012 Elsevier Ltd. All rights reserved.