DSpace Angular :: Browsing by Author "de la Fuente, Juan C."

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

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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.
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.
Experimental measurement and modeling of the solubility of fluorinated compounds derived from dichlone in supercritical carbon dioxide
(2024) Arevalo, Vicente D.; Cabrera, Adolfo L.; Zacconi, Flavia C.; Morales-Guerrero, Sebastian; del Valle, Jose M.; Taborga, Lautaro; de la Fuente, Juan C.
Dichlone, also known as 2,3-dichloronaphthalene-1,4-dione, is a solid organic substance employed in the field of agriculture for its fungicidal properties and as a retardant for vegetable decomposition. The bioactive properties of dichlone can be enhanced by modifying its structure, specifically through the synthesis of new derivatives achieved by replacing the functional groups within its molecular structure. Two new solid dichlone derivatives were synthesized in this work, namely 2-chloro-3-((4-fluorobenzyl)amino)naphthalene-1,4-dione (dCl-2B-F) and 2-chloro-3-((4-fluorophenethyl)amino)naphthalene-1,4-dione (dCl-3 P -F) and measured their solubility in supercritical carbon dioxide at (313, 323, and 333) K and pressures between (9. to 32) MPa. The results indicated that solubility ranged between 30.5 and 47.9 mu mol of solute/mol of CO 2 for dCl-2B-F, and from 2.2 to 243.5 mu mol of solute/mol of CO 2 for dCl-3 P -F. The solubility data of dichlone and its synthesized derivatives (dCl-2B-F, dCl3 P -F, 2-chloro-3-((4-chlorobenzyl)amino)naphthalene-1,4-dione (dCl-2B-Cl), 2-chloro-3-((4-chlorophenethyl) amino)naphthalene-1,4-dione (dCl-3 P -Cl), 2-(benzylamino)-3-chloronaphthalene-1,4-dione (dCl-2B) and 2chloro-3-(phenethylamino)naphthalene-1,4-dione (dCl-3 P)) was compared using the density-based correlation of Chrastil and the Statistical Associating Fluid Theory of Variable Range Mie-potential (SAFT-VR Mie) equation of state (EoS), to better comprehend the effects of the structural differences on the solubility. As a result, for the Chrastil model, a root mean square deviation ( rmsd ) of 3% was obtained for dCl-2B-F and 16% for dCl-3 P -F, whereas for the SAFT-VR Mie equation, it averaged 24% for dCl-2B-F and 28% for dCl-3 P -F. It was found that the solubility of the homologous compounds, differing only in one methylene group, increased with solute size (-2B derivatives were less soluble in CO 2 than the -3 P ones), contrary to the expected trend, which could be attributed to the increased probability of ring -to -ring interactions as the chain length connecting the rings decreases. This demonstrates that geometric factors, along with the pressure and temperature, affect the behavior of the solubility and these should be accurately represented in the predictive models.
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.
Measurement and modeling of high-pressure (vapor plus liquid) equilibria of (CO₂ + alkanol) binary systems
(2011) Bejarano, Arturo; Gutierrez, Jorge E.; Araus, Karina A.; de la Fuente, Juan C.
Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO2 + 3-methyl-2-butanol), (CO2 + 2-pentanol), and (CO2 + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO2 + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively. (C) 2011 Elsevier Ltd. All rights reserved.
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.
Solubility in supercritical carbon dioxide of two novel amine derivatives of 2,3-dichloronaphthalene-1,4-dione (dichlone)
(2023) Schulz, Alex C.; Zacconi, Flavia C.; Cabrera, Adolfo L.; del Valle, Jose M.; Espinoza, Luis; de la Fuente, Juan C.
Dichlone (2,3-dichloronaphthalene-1,4-dione) is an important antimicrobial agent for agriculture, which effectiveness could be improved by modifying its structure, while the recovery of high-purity synthesized derivatives from a reaction mixture could be accomplished by extracting them with supercritical carbon dioxide. Two new amine derivatives, 2-chloro-3-((4-chlorobenzyl)amino)naphthalene-1,4-dione (dCl-2B-Cl) and 2-chloro-3-((4-chlorophenethyl)amino)naphthalene-1,4-dione (dCl-3P-Cl), were synthesized from dichlone, and their solubility in supercritical carbon dioxide was measured afterwards at (313, 323 and 333) K and a pressure range from (8-33) MPa. Experimental solubilities spanned from (10.3 center dot 10(-6) to 22.1 center dot 10(-6)) mol center dot mol(-1) for dCl-2B-Cl, and from (32.7 center dot 10(-6) to 131 center dot 10(-6)) mol center dot mol(-1) for dCl-3P-Cl. The solubility data of the dichlone family (dichlone, dCl-2B-Cl, dCl-3P-Cl, 2-(benzylamino)-3-chloronaphthalene-1,4-dione (dCl-2B) and 2-chloro-3-(phenethylamino)naphthalene-1,4-dione (dCl-3P)) was compared using three models, i.e., the Chrastil equation, the Molecular Connectivity Indices model, and the Statistical Associating Fluid Theory of Variable Range and Mie Potential equation of state, to identify the quantitative structure-property relationship between them. Solubility had an inverse relation with solute size and polarity, but there were some exceptions that could be explained by performing a stereochemical analysis, which showed that steric effects involved in the folding of dCl-3P and dCl-3P-Cl provided them a better geometry for solvation than dCl-2B and dCl-2B-Cl, respectively, making them more soluble. This demonstrates that the solute geometry is an important factor in the solvation process, and it must be represented accurately to develop better predictive models.
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).
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.
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.
Supercritical CO₂ extraction of aqueous suspensions of disrupted Haematococcus pluvialis cysts
(2022) Aravena, Raul, I; del Valle, Jose M.; de la Fuente, Juan C.
This contribution compares the supercritical (SC) CO2 extraction of astaxanthin from disrupted Haematococcus pluvialis cysts in either an aqueous suspension or packed bed of dry powder at 40 or 70 degrees C and 35-55 MPa. The initial stage of the process for aqueous suspensions consisted of a solubility-controlled removal of water that delays oleoresin extraction in comparison to the dry substrate. In addition, residual water in the partially dried suspension made oleoresin extraction slower than from the dry substrate. However, the presence of water in an aqueous suspension surprisingly made the oleoresin extraction more sensitive to temperature in comparison to dry powder, affecting the selectivity of the extraction for astaxanthin in a large extend.
Supercritical CO₂ extraction of pinocembrin from Lippia origanoides distillation residues. 1. Multicomponent solubility and equilibrium partition
(2022) Arias, Julian; Martinez, Jairo; Stashenko, Elena; del Valle, Jose M.; de la Fuente, Juan C.
Steam-distilled oregano (Lippia origanoides) distillation process was analyzed and described as a model binary mixture. The most abundant identified and selected compounds were pinocembrin, a high-value flavonoid, as representative of the minor fraction, and octacosane, a cuticular wax, of the major fraction. Thermodynamic solubility of the solid multicomponent mixture in supercritical CO2 was measured at 313 K and 323 K, and pressures from 8.6 to 32.1 MPa, using a dynamic-analytical method with on-line HPLC analysis. The molar fraction of pinocembrin in CO2-rich phase was assessed from 4.8.10(-6) to 33.10(-6) mol/mol. The solid + fluid equilibrium for the ternary model system was modeled with the Peng-Robinson equation of state and the classical van der Waals mixing rules. Extraction experiments of the solid multicomponent mixture with supercritical CO2 modified with 2-9% w/w ethanol, were carried out in a one-pass pilot scale apparatus at 308 K, 323 K and 338 K, and pressures of 18 MPa, 26 MPa, and 34 MPa. For each sample, the pinocembrin content was assessed. The extraction curves for oleoresin and pinocembrin were represented with empirical models from which the oleoresin partition constants were estimated, that were in range from 0.03 to 0.13 kg/kg substrate/CO2 depending on extraction conditions. However, the partition constant remained virtually invariant, independently of changes in the extraction temperature and pressure conditions, and the ethanol content in CO2, with an average value of 0.08 kg/kg substrate/CO2. These results will facilitate using a simplified mass transfer model to describe oleoresin extraction from steam-distilled L. origanoides.
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.
Use of Hansen solubility parameters to select supercritical carbon dioxide cosolvents for improved extraction selectivity: Case study on green tea decaffeination
(2025) del Valle Lladser, José Manuel; Cuellar Alvarez, Laura María; Canales Muñoz, Roberto Ivan; de la Fuente, Juan C.; Núñez, Gonzalo A.
This study explores the selective decaffeination of green tea using supercritical (SC) CO 2 modified with ethanol and/or water as cosolvents based on experimental data in eight manuscripts in literature. We analyzed the solubility trends of caffeine (data from three literature sources) and epigallocatechin-3-gallate (EGCg) (data from a single source) using the Hansen solubility parameter (HSP) model to evaluate the solute-solvent interactions through the distance parameter R. We identified that the highest selectivity (favoring caffeine removal and EGCg retention) occurred at 70 ◦ extraction C and ≥25 MPa using pure CO 2 and hypothesized that the addition of water facilitated substrate swelling and improved inner mass transfer. Ethanol showed limited benefits at higher pressures. Data for operational solubility were more in line with actual solubility than apparent solubility, although both were still dependent on substrate-solute interactions. Solubility measurements revealed a significant scatter in the data, particularly for caffeine in water- and/or ethanol-modified CO 2 , underscoring the need for better experimentally derived data. Despite these challenges, HSP-based approaches effectively identified conditions that maximized selective decaffeination while preserving EGCg content.

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