Solubilities of Palmitic Acid + Capsaicin in Supercritical Carbon

Article Cite This: J. Chem. Eng. Data XXXX, XXX, XXX-XXX

pubs.acs.org/jced

Solubilities of Palmitic Acid + Capsaicin in Supercritical Carbon Dioxide Miguel G. Arenas-Quevedo,† Octavio Elizalde-Solis,*,† Abel Zúñiga-Moreno,‡ Ricardo Macías-Salinas,† and Fernando García-Sánchez§ †

Departamento de Ingeniería Química Petrolera and Sección de Estudios de Posgrado e Investigación, Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, UPALM, Ed. 8, Lindavista, 07738 Ciudad de México, Mexico ‡ Departamento de Ingeniería Química Industrial, Laboratorio de Investigación en Fisicoquímica y Materiales, Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, Ed. Z-5, 2° piso, UPALM, Lindavista, 07738 Ciudad de México, Mexico § Gerencia de Ingeniería de Recuperación Adicional, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte No. 152, 07730 Ciudad de México, Mexico S Supporting Information *

ABSTRACT: Solubilities of a solid binary mixture of palmitic acid and capsaicin in supercritical carbon dioxide (CO2) are reported in this work. Measurements were carried out in a semiflow apparatus at 308.15 and 328.15 K, and pressures ranging from 10 to 35 MPa. Experiments were replicated at least three times in order to check for the repeatability. The suitability of this apparatus was verified by determining the solubility of naphthalene and of an equimolar solid binary mixture constituted by naphthalene and phenanthrene in supercritical CO2. Solubilities of naphthalene are available in the literature and our measurements were found to be in good agreement with those vast data sets. Additionally, the method proposed by Mendez-Santiago and Teja to test the self-consistency of experimental data was used. Regarding the solid mixture naphthalene + phenanthrene, our results also agree with some literature data. The palmitic acid + capsaicin mixture was also prepared equimolarly. Solubility of palmitic acid was higher than that of capsaicin in the supercritical solvent. Besides, solubility of capsaicin and palmitic acid in the ternary system (solute + solute + CO2) was not significantly improved compared with those reported elsewhere for the binary systems (solute + CO2).

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to Kirschbaum-Titze et al.,2 Collera-Zúñiga et al.,3 and Knez et al.,4 capsaicinoids, carotenoids, fatty acids, and tocopherols are the most representative compounds contained in some species of the genus Capsicum. The main goal of this work was to measure the solubility of palmitic acid + capsaicin in supercritical carbon dioxide and study the synergetic effect. The solubilities of a solid mixture, composed by capsaicin (one of the most important capsaicinoids) and palmitic acid (a fatty acid) in supercritical CO2 were performed in a semiflow apparatus. Measurements were made in the pressure range of 10 to 35 MPa at two temperatures, one was 308.15 K because it is the nearest possible condition to the critical temperature of the solvent, and the other was 328.15 K, which is below the temperature conditions where the thermal degradation of natural compounds can take place.

INTRODUCTION

Extraction of chemicals from natural products using supercritical solvents is of interest in the pharmaceutical, food, and cosmetic industries. Advantages, such as a free-solvent extract and low temperature processing, are obtained applying supercritical fluid extraction (SFE), especially when using carbon dioxide (CO2). A key information in the development of SFE is the solubility of a single solid in the supercritical fluid. This information plays an important role when establishing the technical and economic feasibility of a SFE process.1 However, many different compounds are presented when an extraction process is performed for a natural product (i.e., fruit, vegetable, spice, etc.); then, the solubility of the key component and the selectivity of the supercritical solvent are of relevance. A better picture to try solving and understanding the phenomena involved, is to determine the solubility of a solid mixture with the representative compounds contained in the natural product. Our interest is related to the extraction of capsaicin from the genus Capsicum using supercritical carbon dioxide. According © XXXX American Chemical Society

Received: June 22, 2017 Accepted: October 5, 2017

A

DOI: 10.1021/acs.jced.7b00576 J. Chem. Eng. Data XXXX, XXX, XXX−XXX

Journal of Chemical & Engineering Data

Article

Table 1. Experimental Conditions for Naphthalene Solubility in CO2 Reported in the Literature5−34

a

reference

T/K

p/MPa

method

purity

Tsekhanskaya et al.5 Tsekhanskaya et al.6 McHugh and Paulatis7 Kurnik et al.8 King et al.9 Sako et al.10 Chang and Morrell.11 Lamb et al.12 Dobbs et al.13 Mitra et al.14 Sako et al.15 Iwai et al.16 Chung and Shing17 Reverchon et al.18 Hansen and Bruno19 Chen and Tsai20 Suoqi et al.21 Liu and Nagahama22 Kalaga and Trebble23 Sauceau et al.24 Goodarznia and Esmaeilzadeh25 Diefenbacher and Türk26 Pauchon et al.27 Zúñiga-Moreno et al.28 Zúñiga-Moreno et al.28 Suleiman et al.29 Fu et al.30 Pérez et al.31 Kong et al.32 Rosa et al.33 Wagner et al.34

307.75, 308.65 308.00−328.00 308.15, 328.15 308.00 308.00 308, 318 318.00, 328.00 323.15, 328.15, 331.65 308.15 309.15, 328.15 308.15 308.00 308.15 308.15 328.15 308.20, 328.20 310.00−334.00 308, 318 308.2, 318.2 308.15, 318.15 308.2 308 308.15 317.77, 322.67, 327.56 313.11, 318.13, 323.1, 328 308.15 313, 323, 333 308.2, 328.2 308.15 308 308, 328

4.70−8.20 6.00−33.50 8.21−28.78 12.50−25.30 11.90−25.20 8.34−30.01 8.30−27.60 12.00−50.00 12.20−35.00 7.54−27.68 12.10−20.40 8.50−23.80 7.30−26.50 9.00−23.00 6.50−10.30 9.80−20.05 8.00−10.00 8.34−30.01 9.13−20.69 8.00−30.00 9.80−20.00 8.80−20.80 7.19−32.15 9.99−20.51 8.747−18.96 20.00 8.00−10.00 6.50−30.00 7.00−40.00 10.00−30.00 8.0−30.1

semiflow semiflow semiflow semiflow semiflow semiflow semiflow static semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow semiflow static static+VTDa semiflow static static CIRb static recirculation

not reported not reported 99+% not reported not reported >99% not reported not reported not reported not reported not reported >99.9% not reported not reported not reported not reported 99% >99% >99% 98% 99% 98% 99% >99% >99% 98% 99% ≥99% 99% ≥99.7% not reported

Vibrating tube densimeter. bChromatographic impulse response.

9.9 to 23 MPa. Gordillo et al.42 also measured the solubility of palmitic acid at 308.15, 318.15, and 328.15 K, and pressures from 10 to 35 MPa. More recently Garlapati and Madras43,44 reported data for this system at 308, 318, and 328 K, and pressures from 12 to 23 MPa. Concerning solubilities of capsaicin in supercritical CO2, these have been reported in five works. Knez and Šteiner45 reported measurements at 298.15, 313.15, and 343.15 K, and pressures from 7 to 40 MPa. Hansen et al.46 published data at 308.15, 318.15, and 328.15 K, and pressures from 12 to 25 MPa. De la Fuente et al.47 measured at 298, 308, 313, and 318 K, and over a pressure range from 6 to 40 MPa. Elizalde-Solis and Galicia-Luna48 reported data at temperatures from 312.86 to 332.92 K, and pressures up to 23 MPa. Valderrama et al.49 measured at 298, 308, and 313 K, and pressures from 7.6 to 36.67 MPa.

The apparatus was tested by measuring the solubility of naphthalene in supercritical CO2. These measurements were compared with published data. Characteristics of the different data sets from the literature5−34 for the solubilities of naphthalene in supercritical CO2 are listed in Table 1. Additionally, the self-consistency method proposed by Mendez-Santiago and Teja35,36 was applied to our data. The system naphthalene + phenanthrene + CO2 was studied at 308.15 and 328.15 K and in the pressure range of 10 to 35 MPa for validation of the solubilities of solid mixtures. It has been published by Kurnik and Reid37 at 308.15 K and pressures from 12 to 28 MPa, while Gopal et al.38 obtained their data sets at 308 and 318 K and pressures up to 28 MPa. Sako et al.10 measured at 308 and 328 K and pressures from 10 to 34.6 MPa. Liu and Nagahama22 published their data at 308.2 K and pressures from 4.87 to 28.23 MPa. As far as we could find, solubilities of the palmitic acid + capsaicin in supercritical carbon dioxide are not reported in the literature. Binary systems, either solubilities of palmitic acid or capsaicin in supercritical CO2, have been previously studied. Solubilities of palmitic acid in supercritical CO2 have been reported in six different publications. Kramer and Thodos39 published experimental data at 318, 328, and 338 K, and at pressures from 14 to 57.5 MPa. Bamberger et al.40 measured at 313 K, and at pressures from 8 to 11 MPa. Maheshwari et al.41 measured at 308, 318, and 328 K, and pressures from 13.8 to 41.4 MPa. Iwai et al.16 report data at 308 K, and pressures from

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EXPERIMENTAL SECTION

Chemicals. Carbon dioxide was provided by Air Products Infra with a stated purity of 99.999%. Naphthalene, phenanthrene, palmitic acid, and capsaicin were supplied by Sigma-Aldrich. Certified purities declared by the provider are listed in Table 2. All of these chemicals were used as received. Apparatus. Experiments for solubility of solids in supercritical carbon dioxide were accomplished in an apparatus based on the semiflow method. The schematic diagram of this apparatus is illustrated in Figure 1. It mainly consisted of the B



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experiment. Quantification of the solid and solid mixture dissolved was made by means UV−vis spectrophotometer or high-performance liquid chromatography (17). Procedure. The solid or the binary solid mixture was loaded in excess, over the basis of its solubility in the gas, on the internal filter located at the bottom of the cell. The amount of the solid(s) loaded in the cell for the different systems were 3 g for naphthalene, 2.5 g for naphthalene + phenanthrene mixture, and 0.5 g for the palmitic acid + capsaicin mixture. Binary mixtures were prepared at equimolar composition. According to the results from Kurnik and Reid,37 Gopal et al.,38 Pennisi and Chimowitz,50 and Lucien and Foster,51 the bed (loading) composition does not have any effect on solubility measurements1 when S2−S3-V equilibrium is present. However, in the occurrence of a liquid phase (i.e., S2−S3-L-V or S-L-V equilibriums) in the solubility measurements, the bed composition as well as the presence of a compound in excess can have an effect on the vapor phase composition,1 this is the case for the experiments carried out with mixed solids at 328.15 K in this work. Borosilicate glass beads were added into the cell in order to reduce the internal volume and favor the mass transfer. Afterward, flanges, devices and tubing were assembled, followed by air evacuation from the circuit using a vacuum pump. Temperature in the cell was set to the desired value. It was externally covered with silicone tubing as a serpentine and asbestos tape as insulation jacket. Afterward, carbon dioxide was released from supply tank to the syringe pump by opening needle valve (2). Then, the needle valves (2,5) were closed and carbon dioxide was compressed in the syringe pump. The needle valve (5) was carefully opened and the fluid was pumped through a preheating section to reach supercritical conditions. Carbon dioxide entered slowly into the cell by the bottom side to fill it at the stated temperature up to reach the desired pressure above its critical conditions. The cell was kept on static mode for a sufficient long time with the aim of reaching equilibrium. Then, micrometering valve (13) was carefully opened in order to allow the fluid phase flow. The flow-rate for the solubilities of naphthalene was 4 mL·min−1, meanwhile it was 13.5 mL·min−1 for the solid mixtures. These flow-rates were evaluated from preliminary experiments performed in an interval of 2 to 15 mL·min−1. The solute loaded into the cell was partially dissolved by the supercritical fluid. Fluid phase containing carbon dioxide with the dissolved solids flowed upward being vented from the top of the cell. This fluid was expanded from supercritical conditions to about atmospheric pressure when it passed through the micrometering valve. This decompression provoked sudden temperature decrease on the micrometering valve and surrounding

Table 2. Characteristics of Chemicals chemical

CAS number

carbon dioxide

[124-38-9]

naphthalene phenanthrene palmitic acid capsaicin

[91-20-3] [85-01-8] [57-10-3] [404-86-4]

supplier Infra - Air Products Sigma-Aldrich Sigma-Aldrich Sigma-Aldrich Sigma-Aldrich

mole fraction purity (supplier) 0.99995 0.998 0.996 0.99 0.96

following accessories: A CO2 supply tank (1), two needle valves (2,5), a syringe pump (3, Teledyne-Isco, model 260D) with a capacity of 266 cm3, a circulating liquid bath (4, Nade, model NCD-2016) to regulate the temperature at 273.65 K in the pump cylinder in order to liquefy CO2 and have a major quantity of CO2 inside the pump cylinder; this bath contains an ethylene-glycol solution as a thermal fluid, a heating tape (6) acted as preheater before the equilibrium cell (7). It has a cylindrical-shape with 2.6 cm of internal diameter, 1.2 cm of wall thickness and 26 cm of length, having an approximately 138 cm3 of internal volume. This cell is made of stainless steel and has a maximum operating pressure up to 45 MPa and a maximum operating temperature of 500 K. The cell has two flanges located at the top and bottom, and was internally equipped with two stainless steel filters screwed in each flange. Filters avoided the entrainment of undissolved solute in the fluid phase outside the cell. Two platinum probes of 100-Ω (8,9 Thermo-Est) are connected to a digital indicator (10, Automatic Systems Laboratories, model F200). Platinum probes were inserted on the top and bottom of the cell and were previously calibrated against a secondary thermometer as reference. The estimated uncertainty was ±0.02 K. A digital manometer (11, Crystal Engineering, model XP2i) was connected at the top of the equilibrium cell. This manometer was calibrated against a primary reference having an estimated uncertainty of ±0.01 MPa. A circulating liquid bath (12, Polyscience, model: 8001, temperature stability: ± 0.01 K) used water as thermal fluid to regulate the temperature of the cell. A micrometering valve (13, High Pressure Equipment) located on the exit of the equilibrium cell allowed flowing CO2 through the apparatus. This valve was heated by means of a heating tape to avoid plugging of the tubing line. The temperature at this point was kept slightly higher than the temperature in the equilibrium cell. The dissolved solids were collected in a cooling trap (14) constituted by two U-shaped borosilicate tubes. A rotameter (15, Omega, model 3007SA) allowed monitoring CO2 flowrate. A wet gas meter (16, Shinagawa, model: WNK0.5A) was used to measure the CO2 volume that flowed along the

Figure 1. (1) Gas supply tank; (2,5) needle valves; (3) syringe pump; (6) preheater; (7) equilibrium cell; (8,9) platinum probes; (10) temperature indicator; (11) digital manometer; (4,12) recirculating liquid baths; (13) micro metering valve; (14) cooling trap; (15) rotameter; (16) wet gas meter; (17) analytical equipment (UV−vis, or HPLC). C



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Flexar) equipped with an UV−vis detector. Analytical conditions were the same for calibration and samples from solubility experiments. The naphthalene + phenanthrene was separated in an analytical PAH column (PerkinElmer) using acetonitrile:water (70:30) as mobile phase, and the detection wavelength was set to 254 nm. The palmitic acid + capsaicin was separated in a Bio C18 column (PerkinElmer), using a methanol:water solution (95:5) as the mobile phase at a wavelength set to 292 nm. A linear equation was set to relate absorbance with concentration for pure components as external standards. Detailed HPLC conditions, calibration curves, and chromatograms for naphthalene, phenanthrene, palmitic acid, and capsaicin are included as Supporting Information in Figures S3−S10.

tubing that consequently could cause plugging. It is important to note that the preheater, equilibrium cell, and micrometering valve sections were covered with insulating material. Solids were collected into the two glass U-shaped tubes arranged in series; however, the major solid quantity precipitation took place in the tubing line placed on the outside of the micrometering valve and the first U-tube. These tubes were submerged in a cooling bottle at 273 K to ensure the complete solid precipitation into them induced by the expansion effect and the low temperature in the trap. Meanwhile, carbon dioxide was released and passed throughout the rotameter in order to estimate the flow-rate of the gas phase. Finally, CO2 was sent into the wet gas meter to quantify the total amount of the carbon dioxide. The cumulative carbon dioxide volume was determined from the beginning to the final stage in continuous flow mode. U-shaped tubes and tubing lines in the expansion section were rinsed with organic solvents to collect all remaining solids. Naphthalene was collected with toluene, naphthalene + phenanthrene was recovered with toluene and the palmitic acid + capsaicin was collected with ethanol. For each case, this solution was immediately poured into a volumetric flask and sealed for analysis with a known solvent volume. Each solid sample was analyzed to determine the concentration in terms of mass of solute per volume of organic solvent. Solubility of the solid in the supercritical fluid was reported in mole fraction. Several samples were taken at different times on the continuous mode at each pressure in order to guarantee equilibrium conditions and verify the repeatability. Samples were collected after 5, 10, 15, 20, 30, 45, 60, 90, and 120 min. These analyses indicated that the solute mole fraction in the fluid phase was unstable and it was unsaturated for experiments carried out within 45 min of elapsed time; whereas the solubility were stable with elapsed times higher than 60 min, which indicated that saturated conditions were achieved. Therefore, experiments were accomplished with 60 min as the elapsed time necessary to attain equilibrium conditions with repeatable values in composition. This is valid only for naphthalene and naphthalene + phenanthrene studies. The same procedure was applied to the palmitic acid + capsaicin system where the adequate elapsed time was 90 min. Each solubility datum came from the average of three consecutive experiments with repeatability lower than 5%. A new pressure was set on static mode. After stabilization, the operation in continuous mode was newly stated. This procedure was repeated for each pressure. Then, the solid or solid mixture was again loaded for a new solubility isotherm from low pressure up to reach the maximum pressure. The experimental uncertainties for this property in mole fraction were estimated to be within U(ynap) = 6 · 10−4, U(ynap) = 5 · 10−4 and U(yphe) = 2 · 10−4, and U(ypal) = 0.1ypal + 4 · 10−8 and U(ycap) = 5 · 10−5, for naphthalene, naphthalene + phenanthrene, and palmitic acid + capsaicin systems, in that order. Uncertainties from instruments calibration, analytical equipment, and repeatability were considered in the evaluation of expanded uncertainty. Analyses. Solutions of naphthalene were quantified by using an UV−vis spectrophotometer (Genesys, model 10S) at a wavelength of 254 nm. The calibration was carried out by external standards to relate absorbance with the different concentrations of the solid dissolved in toluene. Spectra and calibration curve are provided in Figures S1 and S2 of the Supporting Information. In the case of binary solid mixture samples, these were analyzed in a HPLC (PerkinElmer, model

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RESULTS AND DISCUSSION Naphthalene + CO2. The solubility of naphthalene in carbon dioxide was studied with the aim of verifying the reliability of our experimental methodology and apparatus in the measurements of this kind of property. Solubilities of naphthalene in CO2 are listed in Table 3. Isothermal trends Table 3. Solubility of Naphthalene in Supercritical Carbon Dioxidea T/K = 308.15 p/MPa 8.50 9.51 11.02 12.52 13.71 15.05 16.57 18.08 19.59 21.03 23.12 25.13 27.65 30.16 32.69 35.17

T/K = 328.15 −1

ynap·10 /mol·mol 3

7.8 9.2 11.2 13.0 14.1 15.0 16.0 16.7 17.1 17.4 17.7 17.8 18.0 18.1 18.3 18.3

p/MPa

ynap·103/mol·mol−1

11.13 12.51 14.04 15.05 16.04 17.06 18.06 19.09 20.52 22.09 23.53 25.07 27.10 30.09 33.12 36.14 39.14

7.2 14.6 22.2 26.8 30.5 33.3 36.5 38.6 41.7 44.6 47.3 50.2 52.0 53.3 53.9 54.1 54.5

a

Standard uncertainties are u(T) = 0.02 K, u(p) = 0.01 MPa. The combined expanded uncertainty is U(ynap) = 6 · 10−4 mol/mol with 0.95 level of confidence (k ≈ 2).

obtained in this work and those published elsewhere are depicted in Figure 2 at about 308 K, which tend to collapse to a straight line. Solubility data at high pressure were in agreement with those from Tsekhanskaya et al.,5,6 only some points presented few deviations. Our values were higher than those declared by Sauceau et al.24 above 20 MPa, but these were within the estimated uncertainty. The opposite occurred when comparing our results against those from McHugh and Paulaitis.7 Our data were lower than those published by those authors and by Kong et al.32 for pressures higher than 22 MPa and out of our claimed uncertainty. A better single trend was observed on the isothermal solubilities in Figure 3 at 328 K. Slight discrepancies were found between our data sets and those reported by Lamb et al.12 for pressures above 35 MPa at 328.15 K. Their results D



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and 328 K present a crossover in the pressure interval from 10 to 15 MPa. It increases as pressure rises at constant temperature, as well as it rises with temperature increments approximately above 13 MPa. The opposite occurred at lower pressures, the solubility is lower at 328 K than those corresponding at 308 K. Additionally, the self-consistency test proposed by MéndezSantiago and Teja35,36 was applied to those data collected in Table 1 but stated within the range of 308 to 328 K including our results. This test is based on the following expression: T ln E = A + Bρ

(1)

where constants A and B are adjustable parameters and are independent of temperature, ρ is the CO2 density at the same temperature and pressure of the solubility datum, E is the enhancement factor given by E = y2 p /p2sub

(2)

psub 2 is the solid sublimation pressure and y2 is the solid mole fraction. Densities for CO2 were calculated with the multiparameter equation proposed by Span and Wagner,52 and sublimation pressure was calculated using an Antoine-type equation with parameters taken from the work by Ahlers et al.53 The self-consistency test was implemented for 474 data points of which 80 data were excluded since the relative deviation was higher than 50%. The rest of these data were assumed as internally consistent which were plotted in Figure 4 according to eq 1. Besides, the solubilities considered at different

Figure 2. Solubility of naphthalene in carbon dioxide: Tsenkhaskaya et al.6 at 308 K, open square; McHugh and Paulaitis7 at 308.15 K, open circle; Dobbs et al.13 at 308.15 K, open, upside-down triangle; Sako et al.15 at 308.15 K, open diamond; Iwai et al.16 at 308.15 K, diamond with a vertical line; Chung and Shing17 at 308.15 K, open, left-pointing triangle; Reverchon et al.18 at 308.15 K, open, right-pointing triangle; Chen and Tsai20 at 308.20 K, star; Liu and Nagahama22 at 308.15 K, star with a vertical line; Kalaga and Trebble23 at 308.2 K, vertical line; Sauceau et al.24 at 308.15, asterisk; Goodarznia and Esmaeilzadeh25 at 308.2 K, horizontal line; Diefenbacher and Türk26 at 308 K, ×; Pauchon et al.27 at 308.15, square with a horizontal line; Kong et al.32 at 308.15 K, plus sign; This work at 308.15 K, filled-in circle.

Figure 4. Correlation for the solubility of naphthalene in carbon dioxide using the Méndez-Santiago and Teja35,36 method published in the range of 308 to 328 K. Tsekhanskaya et al.,6 open square; McHugh and Paulaitis,7 open circle; Chang and Morrell,11 square with a vertical line; Lamb et al.,12 circle with a vertical line; Dobbs et al.,13 open, leftpointing triangle; Mitra et al.,14 triangle with a vertical line; Sako et al.,15 open triangle; Iwai et al.,16 vertical line; Chung and Shing,17 star; Reverchon et al.,18 plus sign; Hansen and Bruno,19 downward facing triangle with a vertical line; Chen and Tsai,20 ×; Liu and Nagahama,22 horizontal line; Kalaga and Trebble,23 asterisk; Sauceau et al.,24 square with a plus sign; Goodzarnia and Esmaeilzadeh,25 circle with a plus sign; Diefenbacher and Türk,26 right-pointing triangle with a vertical line; Pauchon et al.,27 triangle with a plus sign; Zúñiga-Moreno et al.,28 downward-pointing triangle; Fu et al.,30 left-pointing triangle with a plus sign;Kong et al.,32 diamond with a plus sign; Wagner et al.,34 diamond; This work, filled-in circle. Line represents calculated values.

Figure 3. Solubility of naphthalene in carbon dioxide. Tsenkhanskaya et al.6 at 328 K, right-pointing triangle; McHugh and Paulaitis7 at 328.15 K, downward-facing triangle; Chang and Morrell11 at 328 K, left-pointing triangle; Lamb et al.12 at 328.15 K, open triangle; Mitra et al.14 at 328.15 K, open diamond; Hansen and Bruno19 at 328.15 K, horizontal line; Chen and Tsai20 at 328.2 K, open circle; ZúñigaMoreno et al.28 at 328.15 K, ×; This work at 328.15 K, filled-in circle.

increased as pressure was rising although these tended to decrease above 33 MPa. Whereas, the increment of our solubility data sets is not significant at high pressures. Few experimental data did not allow a good comparison and a consequent criterion for the correct reliable sets at these highpressure conditions. Solubility isotherms for naphthalene at 308 E



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temperatures collapse to a single straight line. Parameters A and B, and average absolute relative deviation (AARD) are listed in Table 4. The average absolute relative deviation for the 394 Table 4. Parameters and Deviations for the Correlated Solubility Data Using the Méndez-Santiago and Teja Method35,36 A/K

system

B/K·m3·kg−1

naphthalene + CO2 naphthalene (binary) 1229.247 1.98301 naphthalene + phenanthrene + CO2 naphthalene (pseudobinary) 1146.1 2.0347 phenanthrene (pseudobinary) 1736.8 2.8061 palmitic acid + capsaicin + CO2 palmitic acid (pseudobinary) 4616.0 2.4639 capsaicin (pseudobinary) 8149.4 2.3551 a

%AARDa 20.9 2.44 2.95 3.18 0.61

N

AARD/% = (100/N ) ∑i = 1 |yi ,exp − yi ,cal |/yi ,exp

data was 20.9%. Our experimental data covered a density solvent interval of 427 to 953 kg·m−3 and yielding an AARD = 22.2%. Based on this method, we confirmed the consistency of our solubility data. Naphthalene + Phenanthrene + CO2. We also measured the solubility of the solid mixture naphthalene + phenanthrene in supercritical CO2. We could find measurements at 308, 318, and 328 K published elsewhere.10,22,37,38 Our results are listed in Table 5, and are also plotted in Figures 5 and 6 as well as the

Figure 5. Solubility of naphthalene + phenanthrene in supercritical CO2. Literature data were measured as binary systems: Kurnik and Reid37 at 308 K, open triangle; Gopal et al.38 at 308 K, open square; Sako et al.10 at 308 K, right-pointing triangle; and Liu and Nagahama22 at 308.2 K, open diamond; This work (ternary system) at 308.15 K, filled-in circle. Black and blue symbols denote the solubilities of naphthalene and phenanthrene, in that order.

Table 5. Solubility of Naphthalene + Phenanthrene in Supercritical Carbon Dioxidea p/MPa 10.15 15.22 20.30 25.28 30.13 35.22 10.13 15.24 20.30 25.32 30.36 35.13

ynap·103/mol·mol−1

yphe·103/mol·mol−1

T/K = 308.15 K (solid−vapor phases) 13.3 17.3 19.5 21.4 22.8 23.1 T/K = 328.15 K (liquid−vapor phases) 12.3 22.0 29.2 34.7 38.4 42.0

1.6 2.0 2.2 3.1 3.2 3.3 1.3 5.5 8.5 11.5 13.4 15.9

Figure 6. Solubility of naphthalene + phenanthrene in supercritical carbon dioxide. Solubilities of naphthalene in the ternary system: Sako et al.10 at 328 K, open circle; This work at 328.15 K, filled-in circle. Solubilities of phenanthrene in the ternary system: Sako et al.10 at 328 K, open triangle; This work at 328.15 K, filled-in triangle.

a

Standard uncertainties are u(T) = 0.02 K, u(p) = 0.01 MPa. The combined expanded uncertainty is U(ynap) = 5 · 10−4 mol/mol, U(yphe) = 2 · 10−4 mol/mol with 0.95 level of confidence (k ≈ 2).

corresponding literature data. Our experimental solubilities for naphthalene + phenanthrene follow similar behavior as those reported elsewhere at 308.15 K, as can be seen in Figure 5. The solubility of naphthalene is higher than that of phenanthrene in the ternary system. Most of the data seem to collapse in a straight line for phenanthrene, and a good agreement was found among data. For the case of naphthalene, a high agreement was found between our results with those declared by Kurnik and Reid.37 Their solubilities seem to reach maximum values above 22.5 MPa and tend to decrease above this pressure. The same behavior is presented for those obtained by Sako et al.,10 but the solubilities are lower than

those reported here and by Kurnik and Reid.37 The data published by Gopal et al.38 show more scattering and did not follow a strict increase with pressure. Finally, the data published by Liu and Nagahama22 have slightly higher values than our results and the other sets from the literature; however, these tend to decrease at pressures above 24 MPa. Solubilities for this ternary system obtained in this work and those from Sako et al.10 at 328 K are plotted in Figure 6. It is worth it to say that measurements are located in the fluid region at this temperature according to those sets from Zhang et al.54 These authors found S1−S2-L-G equilibria for the F



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naphthalene + phenanthrene + CO2. Consequently, the solubility isotherm at 328.15 K must be located at the right side of the S1−S2-L-G equilibrium curve in a P−T plot; this condition corresponds to a fluid phase. This behavior has also been reported for measurements at 318.15 K.1,38 Therefore, there could be the possibility of partial or total melting of the solids. In summary, solubility data would not strictly correspond to a solid−fluid phases; instead, we are going to refer to these measurements as mixed-solid solubilities as pointed out by Lucien and Foster.1 Going back to Figure 6, there are marked differences between both sets of data, although mixed-solid solubility of naphthalene in the ternary mixture increase as temperature rises from 308 to 328 K. On the opposite, the mixed-solid phenanthrene solubility declared by Sako et al.9 is almost of the same magnitude at any temperature 308 or 328 K; meanwhile, our data for the mixedsolid phenanthrene solubility increased. We treated the solubility of naphthalene and phenanthrene from the ternary system separately, as pseudobinary systems, in order to correlate them with eq 1. Phenanthrene sublimation pressure was also calculated using an Antoine-type equation with parameters taken elsewhere.53 Results for the pseudobinary system naphthalene + CO2 are depicted in Figure 7a where the whole data measured at 308.15 K are observed to collapse within a straight line, except for a datum from Liu and Nagahama.22 We can easily deduce that measurements obtained by Gopal et al.38 at 318.15 K, Sako et al.10 at 328 K, and some points at 328.15 K in this work, did not collapse to the straight line. The same behavior can be observed in Figure 7b for the pseudobinary system phenanthrene + CO2. However, in this plot the separation between data at 318.15, 328, and 328.15 K is more noticeable, especially for those from this work. This self-consistency test proved that a liquid phase exists at 318.15, 328, and 328.15 K due to the melting of one of the solids or maybe to the melting of the two solids. It is important to remark that measurements at these temperatures would correspond to mixed solid solubilities, as indicated by Lucien and Foster.1 Palmitic Acid + Capsaicin + CO2. The solubility isotherms for the palmitic acid + capsaicin in CO2 obtained in this work are listed in Table 6. These results as ternary mixture along with solubilities of palmitic acid or capsaicin in CO2 available in the literature as binary mixtures are plotted in Figure 8 at 308.15 K and Figure 9 at 328.15 K. Supercritical carbon dioxide dissolved palmitic acid in higher amount in comparison with capsaicin. The solubility increased as temperature was higher, and with pressure rising. It could be caused by the high solvent density and the strong interaction between solute and solvent molecules with pressure rising. Besides, the sublimation pressure was also higher for palmitic acid than the corresponding for capsaicin. Isothermal solubility values at 308.15 K for palmitic acid were 6 times in average higher than those of capsaicin. The solubility of palmitic acid from this work (ternary system) is plotted along with the corresponding property in the binary systems available in the literature16,41,42,44 in Figure 8a at 308.15 K. The solubility of palmitic acid was not greatly improved in the ternary compared to the binary system, except at pressures higher than 25 MPa where this property appreciably increased. This behavior might be caused by the possible presence of a liquid phase due to partial melting of palmitic acid beyond 25 MPa and the presence of a S-L-V equilibria instead of S−V equilibria as

Figure 7. Correlation for the solubilities of naphthalene + phenanthrene in CO2 treated as pseudobinary systems using the Mendez-Santiago and Teja35 method: (a) Correlation for the solubility of naphthalene, and (b) correlation for the solubility of phenanthrene. Kurnik an Reid37 at 308 K, open circle; Gopal et al.38 at 308 K, open square; Sako et al.10 at 308 K, open diamond; Liu and Nagahama22 at 308 K, open triangle; This work at 308.15 K, filled-in circle; Gopal et al.38 at 318 K, downward-facing triangle; Sako et al.10 at 328 K, ×; This work at 328.15 K, filled-in square. Line represents calculated values.

expected; nevertheless it was not possible to confirm because a nonvisual cell was used and experiments about phase transition for this ternary system should be explored. The solubility of capsaicin in CO2 is reported by different authors46,47,49 at 308.15 K. Our data in the ternary and those from the literature in binary systems are plotted in Figure 8b. Here, the solubility of capsaicin in the binary is greater than that for capsaicin in the ternary system. The solubility of the fatty acid was enhanced at 328.15 K and the difference in solubility between these two compounds was noticeable as pressure changed as depicted in Figure 9. Solubility for the fatty acid was five times higher than capsaicin and exhibited a sudden increment above 18 MPa. The maximum difference between solubility values reached 29 times higher at 35.26 MPa. The solubility for palmitic acid has about the same magnitude between 10 and 13 MPa for the two isotherms; whereas the difference between the two isotherms G



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Table 6. Solubility of Palmitic Acid + Capsaicin in Supercritical Carbon Dioxidea p/MPa 10.27 12.19 14.29 16.34 18.13 20.15 22.23 24.37 26.37 28.40 30.22 32.41 35.03 10.35 12.31 14.31 16.37 18.14 20.27 22.18 24.38 26.40 28.18 30.40 32.39 35.26

ypal·103/mol·mol−1

ycap·103/mol·mol−1

T/K = 308.15 (solid−vapor phases) 0.192 0.267 0.371 0.425 0.466 0.483 0.559 0.574 0.624 0.672 0.724 0.753 0.824 T/K = 328.15 (liquid−vapor phases) 0.436 0.526 0.938 1.014 1.513 2.758 4.775 7.274 8.656 9.868 11.646 12.957 15.374

0.032 0.045 0.040 0.062 0.087 0.090 0.109 0.098 0.107 0.126 0.123 0.126 0.142 0.061 0.105 0.192 0.224 0.252 0.306 0.330 0.378 0.418 0.453 0.474 0.509 0.529

a

Standard uncertainties are u(T) = 0.02 K, u(p) = 0.01 MPa. The combined expanded uncertainty is U(ypal) = 0.1ypal + 4 · 10−8 mol/ mol, U(ycap) = 5 · 10−5 mol/mol with 0.95 level of confidence (k ≈ 2).

for the solubility of capsaicin was kept even at low pressures. This behavior at 328.15 K can be explained due to the palmitic acid + CO2 at this temperature is located in the fluid region. It is supported by the S-L-G equilibrium of this system obtained by Gonzalez-Arias et al.,55 Uchida and Kanijo,56 and Bertakis et al.57 The isotherm at 328.15 K would be located at the right side of the S-L-G equilibrium curve. The presence of certain quantity of palmitic acid in liquid phase would explain the increment on the solubility1 in the ternary system. Similar results were published by Kramer and Thodos39 and Maheshwari et al.41 for the binary system at 328.15 K, as can be seen in Figure 9a. Besides, the solubility of palmitic acid in the ternary did not have any increment, it basically kept the same order of magnitude than those for binary systems. For capsaicin, the solubility in the ternary system has a cross over region with the data of the binary system reported by Hansen et al.,46 as can be observed in Figure 9b. Furthermore, a slightly decrement in the solubility of capsaicin in the ternary was noticed compared to that in the binary system at higher pressures. The self-consistency test was implemented with eq 1 for pseudobinary systems for palmitic acid and capsaicin. Results are shown in Figure 10. For palmitic acid, both isotherms do not collapse to a single line, as observed in Figure 10a. Instead we can see that parameters A and B of eq 1 become temperature dependent. The test allowed us to identify a system where a liquid phase is presented and the solubility of

Figure 8. Solubility of palmitic acid + capsaicin in CO2 (ternary system) from this work and solubility of solute in CO2 (binary system) reported in the literature. (a) Palmitic acid: This work at 308.15 K, filled-in circle; Iwai et al.16 at 308.15 K, open diamond; Maheshwari et al.41 at 308 K, open square; Gordillo et al.42 at 308.15 K, open circle; Garlapati and Madras44 at 308.15 K, downward-facing triangle. (b) Capsaicin: This work at 308.15 K, filled-in square; Hansen et al.46 at 308.15, right-pointing triangle; de la Fuente et al.47 at 308 K, open triangle; Valderrama et al.49 at 308 K, open circle.

the partial melting compound is greatly increased due to a cosolvent effect. This last statement refers to the fact that liquid palmitic acid behaves as cosolvent for the solid palmitic acid. For capsaicin, eq 1 fitted better the experimental data, as it is shown in Figure 10b. This probably due to that it corresponds to a solid solubility. Both data sets at 308.15 and 328.15 K collapse to a straight line. Palmitic acid did not behave as a cosolvent to capsaicin; actually the opposite occurred, solubility of capsaicin in the ternary was smaller than in the binary systems. Finally, the consistency of the solubility data for naphthalene and palmitic acid was also verified using the Mendez-Santiago and Teja36 equation for both ternary systems (solute + solvent + cosolvent) assuming phenanthrene and capsaicin as the respective cosolvent. The expression is the following: H



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Figure 9. Solubility of palmitic acid + capsaicin in CO2 (ternary system) from this work and solubility of solute in CO2 (binary system) reported in the literature. (a) Palmitic acid: This work at 328.15 K, filled-in circle; Kramer and Thodos39 at 328 K, open diamond; Maheshwari et al.41 at 328 K, open triangle; Gordillo et al.42 at 328 K, open circle; Garlapati and Madras44 at 328 K, downward-facing triangle. (b) Capsaicin: This work at 328.15 K, filled-in square; Hansen et al.46 at 328.15 K, right-pointing triangle; Elizalde-Solis and GaliciaLuna48 at 328.01 K, open square.

T ln(y2 p /p2sub ) = A′ + B′ρ + C′x3

Figure 10. Correlation of the solubilities of palmitic acid + capsaicin in CO2 treated as pseudobinary systems using the method by MendezSantiago and Teja:35,36 308.15 K, filled-in circle; 328.15 K, open circle. (a) Solubility of palmitic acid and (b) solubility of capsaicin.

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CONCLUSIONS Experimental solubility of a pure solid and two solid mixtures in supercritical carbon dioxide were measured by means of an apparatus based on the semiflow method. According to the good agreement in solubility between our data sets and those reported in the literature for the systems naphthalene + carbon dioxide and naphthalene + phenanthrene + carbon dioxide, it can be assumed that the home-built equipment is suitable for measuring this property. For the binary solid mixtures, carbon dioxide dissolves better naphthalene than phenanthrene in the whole range of pressure at constant temperature. Meanwhile, palmitic acid solubility in carbon dioxide is higher than the values presented for capsaicin. High temperature and high pressure increase the solubility for capsaicin. These conditions favor the selectivity for palmitic acid instead of capsaicin in the supercritical solvent. The self-consistency test was also applied for pseudobinary systems. We assume that this method allowed to identify solubilities of mixed-solids where a liquid phase was presented due to the melting or partial melting of one of the solids or both.

(3)

The adjustable parameters are A′, B′, and C′. It is important to point out that the composition of phenanthrene and capsaicin x3 was not constant since it is a function of temperature and pressure. The data were consistent with AARD about 17% and 23%, in that order. Additionally, these tend to collapse to a straight line in a T ln E − C′ x3 vs CO2 density plot for both systems. However, the model is not so precise at low solvent density. In this region, the relative deviation is higher than 50% for the system that contains palmitic acid. It is worth to say that the model served only for representation and more work has to be done for interpolation of data and of course for predictions. Parameters and the representation from this test are found in Table S1 and Figures S11−S12 of the Supporting Information. I



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(12) Lamb, D. M.; Barbara, T. M.; Jonas, J. NMR Study of Solid Naphthalene Solubilities in Supercritical Carbon Dioxide near the Upper Critical End Point. J. Phys. Chem. 1986, 90, 4210−4215. (13) Dobbs, J. M.; Wong, J. M.; Johnston, K. P. Nonpolar CoSolvents for Solubility Enhancement in Supercritical Fluid Carbon Dioxide. J. Chem. Eng. Data 1986, 31, 303−308. (14) Mitra, S.; Chen, J. W.; Viswanath, D. S. Solubility and Partial Molar Volumes of Heavy Aromatic Hydrocarbons in Supercritical CO2. J. Chem. Eng. Data 1988, 33, 35−37. (15) Sako, S.; Ohgaki, K.; Katayama, T. Solubilities of Naphthalene and Indole in Supercritical Fluids. J. Supercrit. Fluids 1988, 1, 1−6. (16) Iwai, Y.; Fukuda, T.; Koga, Y.; Arai, Y. Solubilities of Myristic Acid, Palmitic Acid, and Cetyl Alcohol in Supercritical Carbon Dioxide at 35°C. J. Chem. Eng. Data 1991, 36, 430−432. (17) Chung, S. T.; Shing, K. S. Multiphase Behavior of Binary and Ternary Systems of Heavy Aromatic Hydrocarbons with Supercritical Carbon Dioxide. Part I. Experimental Results. Fluid Phase Equilib. 1992, 81, 321−341. (18) Reverchon, E.; Russo, P.; Stassi, A. Solubilities of Solid Octacosane and Triacontane in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1993, 38, 458−460. (19) Hansen, B. N.; Bruno, T. J. Solubility Measurement by Direct Injection of Supercritical-Fluid Solutions into a HPLC system. J. Supercrit. Fluids 1993, 6, 229−232. (20) Chen, J. W.; Tsai, F. N. Solubilities of Methoxybenzoic Acid Isomers in Supercritical Carbon Dioxide. Fluid Phase Equilib. 1995, 107, 189−200. (21) Suoqi, Z.; Renan, W.; Guanghua, Y. A method for Measurement of Solid Solubility in Supercritical Carbon Dioxide. J. Supercrit. Fluids 1995, 8, 15−19. (22) Liu, G. T.; Nagahama, K. Solubility of Organic Solid Mixture in Supercritical Fluids. J. Supercrit. Fluids 1996, 9, 152−160. (23) Kalaga, A.; Trebble, M. Density Changes in Supercritical Solvent + Hydrocarbon Solute Binary Mixtures. J. Chem. Eng. Data 1999, 44, 1063−1066. (24) Sauceau, M.; Fages, J.; Letourneau, J. J.; Richon, D. A Novel Apparatus for Accurate Measurements of Solid Solubilities in Supercritical Phases. Ind. Eng. Chem. Res. 2000, 39, 4609−4614. (25) Goodarznia, I.; Esmaeilzadeh, F. Solubility of an Anthracene, Phenanthrene, and Carbazole Mixture in Supercritical Carbon Dioxide. J. Chem. Eng. Data 2002, 47, 333−338. (26) Diefenbacher, A.; Türk, M. Phase Equilibria of Organic Solid Solutes and Supercritical Fluids with Respect to the RESS Process. J. Supercrit. Fluids 2002, 22, 175−184. (27) Pauchon, V.; Cissé, Z.; Chavret, M.; Jose, J. A New Apparatus for the Dynamic Determination of Solids Compounds Solubility in Supercritical Carbon Dioxide. Solubility Determination of Triphenylmethane. J. Supercrit. Fluids 2004, 32, 115−121. (28) Zúñiga-Moreno, A.; Galicia-Luna, L. A.; Camacho-Camacho, L. E. Measurements, of Solid Solubilities and Volumetric Properties of Naphthalene + Carbon Dioxide Mixtures with a New Assembly Taking Advantage of a Vibrating Tube Densimeter. Fluid Phase Equilib. 2005, 234, 151−163. (29) Suleiman, D.; Estevez, L. A.; Pulido, J. C.; Garcia, J. E.; Mojica, C. Solubility of Anti-Inflammatory, Anti Cancer, and Anti-HIV Drugs in Supercritical Carbon Dioxide. J. Chem. Eng. Data 2005, 50, 1234− 1241. (30) Fu, D.; Sun, X.; Qiu, Y.; Jiang, X.; Zhao, S. High-Pressure Behavior of the Ternary System CO2 + Ionic Liquid [bmin] [PF6] + Naphthalene. Fluid Phase Equilib. 2007, 251, 114−120. (31) Pérez, E.; Cabañas, A.; Sanchez-Vicente, Y.; Renuncio, J. A. R.; Pando, C. High-Pressure Phase Equilibria for the Binary System Carbon Dioxide + Dibenzofuran. J. Supercrit. Fluids 2008, 46, 238− 244. (32) Kong, C. Y.; Sone, K.; Sako, T.; Funazukuri, T.; Kagei, S. Solubility Determination of Organometallic Complex in Supercritical Carbon Dioxide by Chromatographic Impulse Response Method. Fluid Phase Equilib. 2011, 302, 347−353.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.7b00576. A typical spectrum for naphthalene and the calibration curve for the UV−vis spectrophotometer using this solid; the calibration curve for the HPLC detector, conditions as well as typical chromatograms for naphthalene, phenanthrene, palmitic acid, and capsaicin; and the representation for the solubility in the ternary systems including the parameters and deviations based on eq 3 (PDF)

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected], [email protected]; Phone: (52) 55 5729-6000 Ext. 55120, 55124. ORCID

Octavio Elizalde-Solis: 0000-0002-7282-3554 Funding

Authors greatly acknowledge the financial support provided by CONACyT and Instituto Politécnico Nacional from MEXICO. Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Lucien, P. F.; Foster, N. R. Solubilities of Solid Mixtures in Supercritical Carbon Dioxide: a Review. J. Supercrit. Fluids 2000, 17, 111−134. (2) Kirschbaum-Titze, P.; Hiepler, C.; Mueller-Seitz, E.; Petz, M. Pungency in Paprika (Capsicum annuum). 1. Decrease of Capsaicinoid Content Following Cellular Disruption. J. Agric. Food Chem. 2002, 50, 1260−1263. (3) Collera-Zúñiga, O.; García Jiménez, F.; Meléndez Gordillo, R. Comparative study of Carotenoid Composition in three Mexican Varieties of Capsicum annuum L. Food Chem. 2005, 90, 109−114. (4) Simonovska, J.; Š kerget, M.; Knez, Ž .; Srbinoska, M.; Kavrakovski, Z.; Grozdanov, A.; Rafajlovska, V. Physicochemical Characterization and Bioactive Compounds of Stalk From Hot Fruits of Capsicum Annuum L. Maced. J. Chem. Chem. Eng. 2016, 35, 199− 208. (5) Tsekhanskaya, Y. V.; Iomtev, M. B.; Mushkina, E. V. Solubility of Naphthalene in Ethylene and Carbon Dioxide under Pressure. Russ. J. Phys. Chem. 1964, 38, 1173−1176. (6) Tsekhanskaya, Y. V.; Roginskaya, N. G.; Mushkina, E. V. Volume Changes in Naphthalene Solutions in Compressed Carbon Dioxide. Russ. J. Phys. Chem. 1966, 40, 1152−1156. (7) McHugh, M.; Paulaitis, M. E. Solid Solubilities of Naphthalene and Biphenyl in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1980, 25, 326−329. (8) Kurnik, R. T.; Holla, S. J.; Reid, R. C. Solubility of Solids in Supercritical Carbon Dioxide and Ethylene. J. Chem. Eng. Data 1981, 26, 47−51. (9) King, M. B.; Alderson, D. A.; Fallah, F. H.; Kassim, D. M.; Kassim, K. M.; Sheldon, J. R.; Mahmud, R. S. In Chemical Engineering at Supercritical Fluid Conditions; Paulatis, M. E., Penninger, J. M. L., Gray, R. D., Davidson, P., Eds.; Ann Arbor Sci.: Ann Arbor, USA, 1983; pp 31−80. (10) Sako, T.; Yamane, S.; Negishi, A.; Sato, M. Solubility Measurement in Crossover Region of Supercritical CO2-Naphthalene-Phenanthrene System. Sekiyu Gakkaishi 1994, 37, 321−327. (11) Chang, H.; Morrell, D. G. Solubilities of Methoxy-1-tetralone and Methyl Nitrobenzoate Isomers and their Mixtures in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1985, 30, 74−78. J



Article

(33) Rosa, A. B. S.; Marceneiro, S.; Braga, M. E. M.; Dias, A. M. A.; De Sousa, H. C. Solubility of All-trans Retinoic Acid in Supercritical Carbon Dioxide. J. Supercrit. Fluids 2015, 98, 70−78. (34) Wagner, K. D.; Dahmen, N.; Dinjus, E. Solubility of Triphenylphosphine, Tris(p-fluorophenyl)phosphine, Tris(pentafluorophenyl)phosphine, and Tris(p-trifluoromethylphenyl)phosphine in Liquid and Supercritical Carbon Dioxide. J. Chem. Eng. Data 2000, 45, 672−677. (35) Méndez-Santiago, J.; Teja, A. S. The Solubility of Solids in Supercritical Fluids. Fluid Phase Equilib. 1999, 158−160, 501−510. (36) Mendez-Santiago, J.; Teja, A. S. Solubility of Solids in Supercritical: Consistency of Data and New Model for Cosolvent Systems. Ind. Eng. Chem. Res. 2000, 39, 4767−4771. (37) Kurnik, R. T.; Reid, R. C. Solubility of Solid Mixtures in Supercritical Fluids. Fluid Phase Equilib. 1982, 8, 93−105. (38) Gopal, J. S.; Holder, G. D.; Kosal, E. Solubility of Solid and Liquid Mixtures in Supercritical Carbon Dioxide. Ind. Eng. Chem. Process Des. Dev. 1985, 24, 697−701. (39) Kramer, A.; Thodos, G. Solubility of 1-Hexadecanol and Palmitic Acid in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1988, 33, 230−234. (40) Bamberger, T.; Erickson, C.; Cooney, L.; Kumar, S. K. Measurement and Model Prediction of Solubilities of Pure Fatty Acids, Pure Triglycerides, and Mixtures of Triglycerides in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1988, 33, 327−333. (41) Maheshwari, P.; Nikolov, L.; White, T.; Hartel, R. Solubility of Fatty Acids in Supercritical Carbon Dioxide. J. Am. Oil Chem. Soc. 1992, 69, 1069−1076. (42) Gordillo, D.; Pereyra, C.; Martínez de la Ossa, E. J. Supercritical Fluid -Solid Phase Equilibria Calculations by Cubic Equations of state and Empirical Equations: Application to the Palmitic Acid + Carbon Dioxide System. J. Chem. Eng. Data 2004, 49, 435−438. (43) Garlapati, C.; Madras, G. Solubilities of Hexadecanoic and Octadecanoic Acids in Supercritical CO2 with and without Cosolvents. J. Chem. Eng. Data 2008, 53, 2913−2917. (44) Garlapati, C.; Madras, G. Solubilities of Palmitic and Stearic fatty Acids in Supercritical Carbon Dioxide. J. Chem. Thermodyn. 2010, 42, 193−197. (45) Knez, Ž .; Steiner, R. Solubility of Capsaicin in Dense CO2. J. Supercrit. Fluids 1992, 5, 251−255. (46) Hansen, N.; Harvey, H.; Coelho, P.; Palavra, M.; Bruno, J. Solubility of Capsaicin and β-Carotene in Supercritical Carbon Dioxide and in Halocarbons. J. Chem. Eng. Data 2001, 46, 1054−1058. (47) De la Fuente, J. C.; Valderrama, J. O.; Bottini, S. B.; Del Valle, J. M. Measurement and Modeling of Solubilities of Capsaicin in HighPressure CO2. J. Supercrit. Fluids 2005, 34, 195−201. (48) Elizalde-Solis, O.; Galicia-Luna, L. A. Solubilities and Densities of Capsaicin in Supercritical Carbon Dioxide at Temperatures from 313 to 333 K. Ind. Eng. Chem. Res. 2006, 45, 5404−5410. (49) Valderrama, J. O.; Robles, P. A.; De la Fuente, J. C. Determining the Sublimation Pressure of Capsaicin using High-Pressure Solubility Data + CO2 Mixtures. J. Chem. Eng. Data 2006, 51, 1783−1787. (50) Pennisi, K. J.; Chimowitz, E. H. Solubilities of Solid 1,10Decanediol and a Solid Mixture of 1,10-Decanediol and Benzoic Acid in Supercritical Carbon Dioxide. J. Chem. Eng. Data 1986, 31, 285− 288. (51) Lucien, F. P.; Foster, N. R. Influence of Matrix Composition on the Solubility of Hydroxybenzoic Acid Isomers in Supercritical Carbon Dioxide. Ind. Eng. Chem. Res. 1996, 35, 4686−4699. (52) Span, R.; Wagner, W. A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple-Point Temperature to 1100 K at Pressures up to 800 MPa. J. Phys. Chem. Ref. Data 1996, 25, 1509−1596. (53) Ahlers, J.; Yamaguchi, T.; Gmehling, J. Development of a Universal Group Contribution Equation of State. 5. Prediction of the Solubility of High-Boiling Compounds in Supercritical Gases with the Group Contribution Equation of State Volume-Translated PengRobinson. Ind. Eng. Chem. Res. 2004, 43, 6569−6576.

(54) Zhang, D.; Cheung, A.; Lu, C.-Y. Multiphase Equilibria of Binary and Ternary Mixtures Involving Solid Phase(s) at SupercriticalFluid Conditions. J. Supercrit. Fluids 1992, 5, 91−100. (55) González-Arias, S.; Verónico-Sánchez, F. J.; Elizalde-Solis, O.; Zúñiga-Moreno, A.; Camacho-Camacho, L. An Enhanced “First Freezing Point” Method for Solid−Liquid−Gas Equilibrium Measurements in Binary Systems. J. Supercrit. Fluids 2015, 104, 301−306. (56) Uchida, H.; Kamijo, T. Measurement and Correlation of the Solid−Liquid−Gas Equilibria for Carbon Dioxide + Normal Chain Saturated Aliphatic Hydrocarbon Systems. J. Supercrit. Fluids 2009, 51, 136−141. (57) Bertakis, E.; Lemonis, I.; Katsoufis, S.; Voutsas, E.; Dohrn, R.; Magoulas, K.; Tassios, D. Measurement and Thermodynamic Modeling of Solid−Liquid−Gas Equilibrium of Some Organic Compounds in the Presence of CO2. J. Supercrit. Fluids 2007, 41, 238−245.

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Solubilities of Palmitic Acid + Capsaicin in Supercritical Carbon

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