Key words: supercritical fluid extraction; shrinking core model; multicomponent extract; Maxwell—Stefan approach
The paper presents a model of supercritical fluid extraction of plant triglycerides from seeds of high-oil raw material. Oil is considered in a two-component approximation. A three-component solution with CO2 is described within the framework of the theory of regular solutions. The sign of the interaction energy of the molecules of the oil components makes it possible to distinguish between two thermodynamic equilibrium modes. Mass transfer through the transport channels of an individual particle is described within the framework of the shrinking core model. Constitutive relations between diffusion fluxes and gradients of chemical potentials are formulated within the framework of the Maxwell— Stefan approach. Each component of the oil has its own front and a pair of shrinking core/transport zone. It is shown that the concentration profiles of the oil components are determined not only by diffusion processes, as is typical in the framework of the one-component approximation, but also by the material two-phase equilibrium of individual components.
doi:10.34984/SCFTP.2023.19.1.001
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ГОСТ
7.0.100-2018
Model of supercritical fluid extraction of vegetable oil in two-component approximation / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 3-16. - DOI: 10.34984/SCFTP.2023.19.1.001
TRANSLIT
Model sverhkriticheskoj flyuidnoj ekstrakcii rastitelnogo masla v dvuhkomponentnom priblizhenii / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 3-16. - DOI: 10.34984/SCFTP.2023.19.1.001
En
Model of supercritical fluid extraction of vegetable oil in two-component approximation. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 3-16 (2024). https://doi.org/10.34984/SCFTP.2023.19.1.001
Key words: saturation line, density, sulfur hexafluoride, order parameter, rectilinear diameter
Information on the behavior of the SF6 density on the binodal in the asymptotic vicinity of the critical point 3·10-6 < τ < 2 · 10 -4, where τ = (Tc - T)/Tc , — relative temperature is presented. The densities of the liquid (ρl) and vapor (ρg) phases were calculated based on the experimental data of Garrabos et al. (2018) about the height h at which the meniscus is located separating the two phases of the sample in a horizontal cell with a diameter d at a temperature T under conditions of Earth gravity. As the second component of the method, the order parameter fs(τ) is considered in analytical form, which corresponds to the scale theory (ST) of critical phenomena and is based on (ρl, ρg,T -data from Funke et al. (1998) for SF6 in the range 10-3 < τ <0,3. Several problems are formulated, including the construction of dependencies ρl(τ) и ρg(τ), corresponding to ST and correlating with (h,T)-data for 10-6 < τ < 10-3. The relationship between (h,T) data and the functions fs(τ) и fd(τ) (where fd is the average or rectilinear diameter) is investigated. The dependences of ρl(τ) and ρg(τ) on temperature in the range 10-6 < τ < 10-3 were calculated. The dependences ρl(τ) and ρg(τ) that correspond to ST and working satisfactorily in the range 10-6< τ < 10-3 were constructed.
doi:10.34984/SCFTP.2023.19.1.002
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ГОСТ
7.0.100-2018
Adaptation of (<i>h,T</i>)-data to calculate some</span> thermodynamic properties of SF<sub>6</sub> on saturation curve / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 17-29. - DOI: 10.34984/SCFTP.2023.19.1.002
TRANSLIT
Adaptaciya (<i>h,T</i>)-dannyh dlya rascheta nekotoryh termodinamicheskih svojstv SF<sub>6</sub> na krivoj nasyshcheniya / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 17-29. - DOI: 10.34984/SCFTP.2023.19.1.002
En
Adaptation of (<i>h,T</i>)-data to calculate some</span> thermodynamic properties of SF<sub>6</sub> on saturation curve. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 17-29 (2024). https://doi.org/10.34984/SCFTP.2023.19.1.002
Key words: supercritical carbon dioxide, molecular dynamics, Raman spectroscopy, Widom delta
An approach to modeling the Raman spectra of supercritical carbon dioxide based on Fourier analysis of the autocorrelation function of the dipole moment calculated by the molecular dynamics method is demonstrated. On its basis, Raman spectra of carbon dioxide were simulated along the 310 K isotherm in the pressure range 0.1–15 MPa. It has been established that in the Widom delta there is a broadening of spectral lines, as well as extrema in the dependences of Raman shifts on pressure. The results obtained are in good agreement with known experimental data and indicate a significant influence of cluster formation on the macroscopic properties of carbon dioxide in the vicinity of the critical point.
doi:10.34984/SCFTP.2024.19.1.003
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ГОСТ
7.0.100-2018
Simulation of raman spectra of supercritical carbon dioxide using the molecular dynamics method / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 30-43. - DOI: 10.34984/SCFTP.2024.19.1.003
TRANSLIT
Modelirovanie Ramanovskih spektrov sverhkriticheskogo dioksida ugleroda metodom molekulyarnoj dinamiki / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 30-43. - DOI: 10.34984/SCFTP.2024.19.1.003
En
Simulation of raman spectra of supercritical carbon dioxide using the molecular dynamics method. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 30-43 (2024). https://doi.org/10.34984/SCFTP.2024.19.1.003
Key words: avermectin, yield, Streptomyces avermitilis, supercritical fluid extraction, carbon dioxide, rotatable uniform plan, optimization.
The process of supercritical fluid extraction of avermectin from the bacterial biomass of Streptomyces avermitilis with carbon dioxide was optimized by the method of a full factorial experiment using a second-order rotatable uniform plan. When planning, the main levels chosen were a pressure of 25 MPa, a temperature of 60°C, and an extraction duration of 100 min. The analysis of the regression equation made it possible to establish the optimal process parameters: 30 MPa, 85°C, and 133 min. In the control experiment, an extract was obtained with a yield of 13 %, containing 41 % avermectin. The yield of avermectin was 5.36 % of absolutely dry biomass, which exceeds the extraction yields obtained using organic solvents.
doi:10.34984/SCFTP.2024.19.1.004
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ГОСТ
7.0.100-2018
Supercritical fluid extraction of avermectin from <i>Streptomyces avermitilis</i> using carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 44-55. - DOI: 10.34984/SCFTP.2024.19.1.004
TRANSLIT
Izvlechenie avermektina iz <i>Streptomyces avermitilis</i> sverhkriticheskim dioksidom ugleroda / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 44-55. - DOI: 10.34984/SCFTP.2024.19.1.004
En
Supercritical fluid extraction of avermectin from <i>Streptomyces avermitilis</i> using carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 44-55 (2024). https://doi.org/10.34984/SCFTP.2024.19.1.004
Key words: supercritical carbon dioxide, siloxane aerogels, ferrocene
An effective method for the synthesis of hybrid structure siloxane aerogels with ferrocene fragments built into polymer structure has been developed. At the initial stage, a gel was obtained by polycondensation of tetraethoxysilane and ferrocene-containing alkoxysilanes, catalyzed by BF3 · Et2O in acetone. The transformation of gels into aerogels was carried out using SC-CO2. The aerogel samples were characterized in detail by Mossbauer spectroscopy and nitrogen adsorption methods, and the density of the materials was determined. The iron content in the resulting aerogels varies in the range of 3.6—8.7 % by weight of iron (or 11.9—28.7 % by weight of ferrocene units).
doi:10.34984/SCFTP.2024.19.1.005
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ГОСТ
7.0.100-2018
Ferrocene-modified siloxane aerogels / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 56-67. - DOI: 10.34984/SCFTP.2024.19.1.005
TRANSLIT
Modificirovannye ferrocenom siloksanovye aerogeli / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 56-67. - DOI: 10.34984/SCFTP.2024.19.1.005
En
Ferrocene-modified siloxane aerogels. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 56-67 (2024). https://doi.org/10.34984/SCFTP.2024.19.1.005
Key words: Hypogymnia physodes, supercritical fluid extraction, low molecular weight phenols, flavonoids, atranorine, antibacterial activity
The process of supercritical fluid extraction of the thallus of the lichen species Hypogymnia physodes with carbon dioxide in the presence of acetone as a co-solvent has been studied. An assessment of extraction conditions (temperature, pressure and duration) on the yields of extract, phenolic compounds, including low molecular weight phenols, atranorine and flavonoids was carried out. It has been shown that the main amount of extractives (up to 90 %) is extracted within 40 minutes of extraction. The extract yield reaches 156.5 mg/g, with a content of phenolic compounds up to 87.3 %. The extracts obtained have high antiradical activity (up to 225 rmol Trolox-equiv/g). A positive correlation has been established between the antiradical activity of extracts and the content of phenolic compounds in them, including atranorine. Antibacterial activity of the extracts was revealed against gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli, Proteus mirabilis) strains of microorganisms.
doi:10.34984/SCFTP.2024.19.1.006
Cite
ГОСТ
7.0.100-2018
Supercritical fluid extraction of the lichen thallus <i>Hypogymnia physodes</i> / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2024. – Т. 19. – № 1. – С. 68-82. - DOI: 10.34984/SCFTP.2024.19.1.006
TRANSLIT
Sverhkriticheskaya flyuidnaya ekstrakciya talloma lishajnika <i>Hypogymnia physodes</i> / – Tekst : neposredstvennyj // Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2024. – Т. 19. – № 1. – S. 68-82. - DOI: 10.34984/SCFTP.2024.19.1.006
En
Supercritical fluid extraction of the lichen thallus <i>Hypogymnia physodes</i>. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 68-82 (2024). https://doi.org/10.34984/SCFTP.2024.19.1.006