Supercritical Fluid Extraction of Cerium from Aqueous Solutions Using Tributyl Phosphate as a Ligand
Key words: extraction, supercritical fluid, cerium complexes, aqueous solutions, tributyl phosphate
The extraction of Ce(III) and Ce(IV) complexes with tributyl phosphate (TBP) from aqueous solutions of various acidity in the presence of a salting-out agent (magnesium nitrate) into supercritical (SC) fluids, CO2 and freon R23, was studied under static and dynamic conditions. It is shown that SC-CO2 is a more efficient extractant than freon R23. The efficiency of Ce(III) extraction increases with an increase in the concentration of magnesium nitrate and the amount of TBP in the system and decreases with an increase in the acidity of the aqueous solution. The dependence of the extraction efficiency on pressure is more complex: at a pressure of SC-CO2 below 10 MPa (at 40 °C), the solubility of TBP in it drops sharply. As the pressure rises above this value, the degree of transition of the Ce(III) complex into the fluid phase decreases. An equation for the extraction isotherm is obtained and its parameters are determined for conditions close to optimal for the extraction of Ce(III). Cerium in the form of Ce(IV) is more efficiently extracted by SC-CO2 even at high acidity of the aqueous solution; however, the state of Ce(IV) in the aqueous solution of its complex is unstable; the complete transition to the Ce(III) state occurs within ~14 days. Dynamic extraction using a countercurrent extraction column cannot be described in terms of the «theoretical separation steps» (or «theoretical plates») model. The reason, apparently, is the instability of the TBP solution in the SC-fluid and the formation of a suspension of small drops of liquid TBP, which is a more efficient extractant than the true solution of TBP in the fluid. At the same time, such a transition leads to a sharp increase of the efficiency of the extraction column as a mass transfer apparatus.
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ГОСТ
7.0.100-2018
Supercritical Fluid Extraction of Cerium from Aqueous Solutions Using Tributyl Phosphate as a Ligand / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 3-25. - DOI: 10.34984/SCFTP.2022.17.1.001
TRANSLIT
/ – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 3-25. - DOI: 10.34984/SCFTP.2022.17.1.001
En
Supercritical Fluid Extraction of Cerium from Aqueous Solutions Using Tributyl Phosphate as a Ligand. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 3-25 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.001
Key words: organo-metallic copper complexes, solubility, supercritical carbon dioxide, copper acetylacetonate, impregnation
The solubility of copper (II) acetylacetonate in supercritical carbon dioxide was studied using a circulation-type setup based on the P-401 supercritical fluid extraction system, and the obtained results were compared with the literature data. The solubility of this complex at 323 and 333 K isotherms was additionally investigated. The possibility of using various metal complex copper compounds in the impregnation treatment
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7.0.100-2018
Solubility of Copper Acetylacetonate(II) in Supercritical Carbon Dioxide as the Basis of polymer Composite materials Modification Technology / – Текст : // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 26-36. - DOI: 10.34984/SCFTP.2022.17.1.002
TRANSLIT
Rastvorimost acetilacetonata medi(II) v sverhkriticheskom diokside ugleroda kak osnova tekhnologii modifikacii polimernyh kompozitnyh materialov / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 26-36. - DOI: 10.34984/SCFTP.2022.17.1.002
En
Solubility of Copper Acetylacetonate(II) in Supercritical Carbon Dioxide as the Basis of polymer Composite materials Modification Technology. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 26-36 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.002
Key words: rapeseed oil hydrolysis, oleic acid oxidation, azelaic acid esterification, heterogeneous catalyst, supercritical conditions, 2-ethylhexyl ether
Three chemical stages of azelaic acid 2-ethylhexyl ester synthesis based on rapeseed oil
were studied: hydrolysis of the initial oil, oxidation of oleic acid in the presence of
palladium-containing heterogeneous catalyst, and esterification of azelaic acid. It is
demonstrated that reactions hydrolysis and esterification can be efficiently carried out
under supercritical conditions (523—653 K and 22.5—30 MPa).
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ГОСТ
7.0.100-2018
On the Efficiency of Carrying out Chemical Reactions under Supercritical Conditions During the Synthesis of Azelaic Acid 2-Ethylhexyl Ether Based on Rapseed Oil / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 37-48. - DOI: 10.34984/SCFTP.2022.17.1.003
TRANSLIT
Izuchenie vozmozhnosti provedeniya v sverhkriticheskih usloviyah himicheskih reakcij pri sinteze 2-etilgeksilovogo efira azelainovoj kisloty na osnove rapsovogo masla / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 37-48. - DOI: 10.34984/SCFTP.2022.17.1.003
En
On the Efficiency of Carrying out Chemical Reactions under Supercritical Conditions During the Synthesis of Azelaic Acid 2-Ethylhexyl Ether Based on Rapseed Oil. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 37-48 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.003
Key words: supercritical fluid extraction, carbon dioxide, acid-base hydrolysis, epigean lichen, Peltigera aphthosa, chitin-containing complex
This research was funded with the financial support of the Ministry of Economic
Development, Industry and Science of the Arkhangelsk Region within the framework of the
project «Obtaining a new chitin-containing material (product) for veterinary and biological
purposes from promising plant sources of the Arkhangelsk Region» (agreement No. 2 dated
September 22, 2021), the Ministry of Science and Higher formation of the Russian Federation
in terms of supercritical fluid extraction (project No. FSRU-2021-0009. Instrumentation of
the Core Facility Center «Arktika» of Northern (Arctic) Federal University and «Critical
technologies of the Russian Federation in the field of environmental safety of the Arctic»
(N. Laverov Federal Center for Integrated Arctic Research) was used in this work.
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7.0.100-2018
Isolation of Chitin-Containing Complexes from the Thalli of the Lichen Species Peltigera Aphthosa / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 49-65. - DOI: 10.34984/SCFTP.2022.17.1.004
TRANSLIT
Vydelenie hitinsoderzhashchih kompleksov iz talloma lishajnika vida Peltigera aphthosa / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 49-65. - DOI: 10.34984/SCFTP.2022.17.1.004
En
Isolation of Chitin-Containing Complexes from the Thalli of the Lichen Species Peltigera Aphthosa. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 49-65 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.004
Key words: water, supercritical propane/butane mixture, phase equilibrium, solubility, thermodynamic model, Peng—Robinson equation of state
The results of an experimental study of the phase equilibrium of the «water—propane/butane»
system carried out in the temperature range of 403—443 K and the pressure range
of 5.28—20.66 MPa using a high-pressure optical cell are presented. The V type of phase
behavior is established. The solubility of water in a supercritical propane-butane mixture
under the above mentioned thermodynamic conditions is estimated based on the
characteristics of the steam branch of the phase equilibrium of the «water—propane/butane»
system and described using the Peng—Robinson equation of state in combination
with the Mukhopadhyay and Rao mixing rule was made.
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ГОСТ
7.0.100-2018
Phase Equilibrium of the Binary System «Water—Propane/Butane» / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 66-75. - DOI: 10.34984/SCFTP.2022.17.1.005
TRANSLIT
Fazovoe ravnovesie binarnoj sistemy «voda—propan/butan» / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 66-75. - DOI: 10.34984/SCFTP.2022.17.1.005
En
Phase Equilibrium of the Binary System «Water—Propane/Butane». Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 66-75 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.005
Key words: palm oil, Shea oil, ethanol, sub- and supercritical fluid conditions, transesterification, biodiesel, kinematic viscosity coefficient
The results of an experimental study of the process of obtaining biodiesel fuel by
transesterification of Shea (Karite) and palm oils carried out in ethanol under supercritical
fluid conditions on a batch unit using preliminary ultrasonic emulsification of the reaction
mixture are presented. The studies were carried out in a temperature range of 623—673 K
at a pressure of 30 MPa, a range of «alcohol—oil» molar ratios of 30—42, and a reaction
duration of 30 minutes. Preferred reaction conditions have been established. The results
of an experimental study of the kinematic viscosity of samples of initial oils and the
product of the transesterification reaction The results of an experimental study of the
kinematic viscosity of samples of initial oils and the product of the transesterification
reaction are presented.
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ГОСТ
7.0.100-2018
The Transeterification of Shea (Karite) and Palm Oils in Supercritical Ethanol / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 1. – С. 76-88. - DOI: 10.34984/SCFTP.2022.17.1.006
TRANSLIT
Pereeterifikaciya masla dereva SHi (Karite) i pal'movogo masla v sverhkriticheskom etanole / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 1. – S. 76-88. - DOI: 10.34984/SCFTP.2022.17.1.006
En
The Transeterification of Shea (Karite) and Palm Oils in Supercritical Ethanol. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 1, 76-88 (2022). https://doi.org/10.34984/SCFTP.2022.17.1.006
Key words: swine manure, chicken manure, biofuel, sub- and supercritical water, liquefaction, carbonization, gasification, oxidation
Treatment of swine and poultry manure (waste of hazard class III) with water at parameters above its critical point (T > 374 °C, P > 22.1 MPa) is considered as one of the promising methods for their environmentally friendly processing. The works devoted to liquefaction, carbonization, and gasification of swine and chicken manure in sub- and supercritical water are analyzed. The problems associated with the practical implementation of waste processing in supercritical water-oxygen fluid are discussed. Their source is, first of all, the high cost of compressed oxygen, the heterogeneous composition of the wastes and the presence of solid particles an them, precipitation of salts and corrosion of structural materials. It is shown that due to the high water content in the wastes and the low calorific value of the organic matter contained in them, the practical implementation of the process in autothermal conditions will require the use of additional fuel.
doi:10.34984/SCFTP.2022.17.2.003
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7.0.100-2018
Disposal of watered toxic waste of pig and poultry rearing in sub- and supercritical water / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 3-23. - DOI:
TRANSLIT
Pererabotka obvodnennyh toksichnyh v sub- i sverhkriticheskoj vode / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 3-23. - DOI:
En
Disposal of watered toxic waste of pig and poultry rearing in sub- and supercritical water. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 3-23 (2022). https://doi.org/
Key words: common juniper, supercritical fluid extraction, terpenes, pigments, liquefied gases, essential oil
The paper presents the results of studying the efficiency of the extraction of the terpene fraction from the tree greenery of common juni per (Juni perus Communis L.) by suband supercritical extraction methods in comparison with traditional methods. The influence of extraction parameters on the qualitative composition of extracts is studied. Identification of the components of the obtained extracts was carried out by chromatography mass spectrometry. It was found that the qualitative compositions of the studied extracts are similar, but they differ significantly in the ratio of the groups of components. It is shown that the greatest extraction of monoterpenes is facilitated by butane extraction under subcritical conditions and hydrodistillation.
doi:10.34984/SCFTP.2022.17.2.001
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7.0.100-2018
Extraction of terpenes of juniperus communis tree greenery under sub- and supercritical conditions / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 24-36. - DOI:
TRANSLIT
Izvlechenie terpenov drevesnoj zeleni mozhzhevel'nika obyknovennogo v usloviyah sub- i sverhkriticheskih vozdejstvij / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 24-36. - DOI:
En
Extraction of terpenes of juniperus communis tree greenery under sub- and supercritical conditions. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 24-36 (2022). https://doi.org/
Key words: critical phenomena, Widom line, optical diagnostic methods, pair correlation function
A fundamental problem of optical diagnostics of the supercritical fluid structure and its statistical properties in the vicinity of the Widom line is considered. To perform the diagnostic procedure one needs some techniques to build the connection between the peculiarities of optical measurement data to the peculiarities of fluid state. A brief review of the results obtained over the past 10 years on the problem of Widom lines in nonpolar supercritical media is presented. Data on the measurements of the nonlinear refractive index and on the Rayleigh light scattering intensity in the region of the Widom line in CO2 is considered in detail. It is demonstrated that these data can serve as the basis for reci procally complementary methods for optical diagnostics of supercritical fluid state. As an example, a small angle light scattering data were used to find the pair correlation function of supercritical CO2. The temperature dependence of the latter differs fundamentally from the temperature dependence of the Ornstein—Zernike pair correlation function. It is noted that the method based on the measuring of the Rayleigh scattering intensity is of a general nature and it can be applied to any random molecular media, including the planet atmosphere.
doi:10.34984/SCFTP.2022.17.2.002
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7.0.100-2018
On the possibilities of optical methods for diagnosing the state of a supercritical fluid near the Widom line / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 37-54. - DOI:
TRANSLIT
O vozmozhnostyah opticheskih metodov diagnostiki sostoyaniya sverhkriticheskogo flyuida vblizi linii Uidoma / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 37-54. - DOI:
En
On the possibilities of optical methods for diagnosing the state of a supercritical fluid near the Widom line. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 37-54 (2022). https://doi.org/
Key words: graphite oxide, membrane, spin probe, supercritical carbon dioxide
A nitroxide spin probe was introduced into graphite oxide membranes from a solution in supercritical carbon dioxide in various modes. It is shown that a slow release of pressure makes it possible to introduce the probe without disturbing the orientational order of the graphene layers, that is, without disturbing the internal structure of the membrane.
doi:10.34984/SCFTP.2022.17.2.004
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7.0.100-2018
Introduction of spin probes into graphite oxide membranes using supercritical carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 55-63. - DOI:
TRANSLIT
Vvedenie spinovyh zondov v membrany iz oksida grafita s pomoshch'yu sverhkriticheskogo dioksida ugleroda / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 55-63. - DOI:
En
Introduction of spin probes into graphite oxide membranes using supercritical carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 55-63 (2022). https://doi.org/
Key words: supercritical extraction, essential oil, Satureja hortensis L., gcms, component content
A comparative estimation of the component composition of supercritical carbon dioxide (SC-CO2) extracts obtained at different thermodynamic parameters and the essential oil of Satureja hortensis L. reveals the differences in the content of separate components. It is determined that the CK-CO2 extract yield at 30 MPa (3.718 %) is more 2 times higher than at 10 MPa (1.792 %) and the essential oil content (1.75 %). The main components are а-Thujene, Myrcene, а-Terpinene, ï-Cymene, У-Terpinene, Thymoquinone, Thymol, Carvacrol, (E)-Caryophyllene, 3-Bisabolene, n-Hexadecanoicacid, methyllinolenate, n-Triacontane. Besides the aforesaid substances,in the extract obtained at 30 MPa and 50 °C there are found 3-cis-Terpineol, Neophytadiene, Hexadecanoicacid, Linoleic, methyllinolenate, n-Pentacosane, n-Hexacosane, n-Nonacosane and Squalene.
doi:10.34984/SCFTP.2022.17.2.005
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7.0.100-2018
The dependence of the component composition of satureja hortensis l. extract on the pressure of the supercritical CO2 extraction process / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 64-74. - DOI:
TRANSLIT
Zavisimost' komponentnogo sostava ekstrakta chabera sadovogo ot davleniya processa sverhkriticheskoj SO2-ekstrakcii / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 64-74. - DOI:
En
The dependence of the component composition of satureja hortensis l. extract on the pressure of the supercritical CO2 extraction process. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 64-74 (2022). https://doi.org/
Key words: ceria-zirconia, solvothermal synthesis, isopropanol, methane dry reforming
Single-phase Ce—Zr-oxides with fluorite structure were synthesized by the solvothermal method in an isopropanol medium at parameters exceeding the critical ones for isopropanol. The influence of synthesis parameters on the characteristics of the obtained materials (specific surface area, morphology, particle size, phase composition) was established. 5 wt. % Ni or 5 wt. % Ni+Co (1:1 by wieght) were deposited by incipient wetness impregnation. The structure and properties of samples were characterized using X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, temperature-programmed reduction by hydrogen, and relationships between the sample composition and catalytic performance (CH4 and CO2 conversion, hydrogen yield and H2/CO ratio) in dry reforming of methane (DRM) were investigated. The effect of the deposited metal component composition and Ce/Zr ratio in the support on the catalytic activity and stability during the DRM process was demonstrated.
doi:10.34984/SCFTP.2022.17.2.006
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7.0.100-2018
Ni and Ni-Co catalysts of carbon dioxide conversion of methane based on mixed Ce-Zg oxides obtained in isopropanol medium / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 2. – С. 75-84. - DOI:
TRANSLIT
Ni i Ni-So katalizatory uglekislotnoj konversii metana na osnove smeshannyh Se-2g-oksidov, poluchennyh v srede izopropanola pri sverhkriticheskih parametrah / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 2. – S. 75-84. - DOI:
En
Ni and Ni-Co catalysts of carbon dioxide conversion of methane based on mixed Ce-Zg oxides obtained in isopropanol medium. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 2, 75-84 (2022). https://doi.org/
Key words: transformation of pyrrole in supercritical water and hydrogen-oxygen fluid
The transformation of pyrrole in supercritical water and hydrogen-oxygen fluid in the flow mode (673-823 K, 25 MPa, acid excess coefficient ≤ 2.46, residence time 18-148 s) was investigated. It was found that in the absence of O2, an increase in temperature leads to an increase in the degree of transformation of pyrrole and the release of gaseous products (H2, CH4, CO and CO2). When pyrrole is oxidized in an oxygenated fluid, the oxygen excess coefficient has a greater effect on the degree of removal of organic carbon than the temperature. The products obtained at 723 and 773 K contain a solid whose IR spectrum corresponds to polypyrrole. In general, the oxidation of pyrrole in the hydrogen-oxygen fluid proceeds by the mechanism of parallel and sequential reactions, including the formation and oxidation of the products of the opening cycle, as well as the formation and oxidation of the polymerization products of pyrrole.
doi:10.34984/SCFTP.2022.17.3.002
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7.0.100-2018
Transformation of pyrrole in supercritical water and hydrogen-oxygen fluid / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 7-18. - DOI:
TRANSLIT
Prevrashchenie pirrola v sverhkriticheskoj vode i vodokislorodnom flyuide / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 7-18. - DOI:
En
Transformation of pyrrole in supercritical water and hydrogen-oxygen fluid. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 7-18 (2022). https://doi.org/
Key words: cobalt, super-stitched polystyrene, subcritical water
The composition and structure of a cobalt-containing catalyst synthesized in a subcritical water medium is investigated. It is determined that the resulting catalyst is characterized by a high specific surface area, and the cobalt-containing phase is represented by filamentous crystals of Co3O4 with a diameter of 10 nm and a length of 100-600 nm.
doi:10.34984/SCFTP.2022.17.3.003
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7.0.100-2018
Structure of cobalt-containing particles stabilized in polymer synthesized in subcritical medium / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 19-25. - DOI:
TRANSLIT
Prevrashchenie pirrola v sverhkriticheskoj vode i struktura stabilizirovannyh v polimere kobal'tsoderzhashchih chastic, sintezirovannyh v subkriticheskoj vode flyuide / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 19-25. - DOI:
En
Structure of cobalt-containing particles stabilized in polymer synthesized in subcritical medium. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 19-25 (2022). https://doi.org/
Key words: supercritical antisolvent deposition, crystallization, morphology, phase equilibria
The dependence of the size and morphology of levofloxacin hydrochloride particles (hereinafter referred to as levofloxacin) deposited by supercritical anti-solvent deposition (A) on the pressure and concentration of the micronized substance in solution is investigated. It is shown that the crystallization of levofloxacin from the two-phase CO2-acetone-levofloxacin system leads to the production of particles with a bimodal size distribution. An increase in pressure causes a change in the deposition regime, and as a consequence, the crystallization of smaller particles. Liquid-gas equilibrium curves for the CO2-acetone-levofloxacin system at a temperature of 40 °C were constructed for the first time.
doi:10.34984/ SCFTP.2022.17.3.004
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7.0.100-2018
Micronization of levofloxacin hydrochloride by supercritical antisolvent deposition from single-phase and two-phase mixtures of CO2—acetone / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 26-36. - DOI:
TRANSLIT
Mikronizaciya gidrohlorida levofloksacina metodom sverhkriticheskogo antisol'ventnogo osazhdeniya iz odnofaznoj i dvuhfaznoj smesej co2—aceton / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 26-36. - DOI:
En
Micronization of levofloxacin hydrochloride by supercritical antisolvent deposition from single-phase and two-phase mixtures of CO2—acetone. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 26-36 (2022). https://doi.org/
Key words: chitosan, lignosulfonate, alginate, aerogel, textural characteristics, supercritical fluid technologies, organic and carbon-native aerogels
Based on two—component hydrogels sodium alginate—chitosan (ALNa—HT) and sodium lignosulfonate—chitosan (LSNa-HT) with the use of supercritical fluid technologies and carbonation, organic and carbon aerogels were obtained. The effect of the solvent-acetone replacement regime in hydrogels on the textural properties of aerogels based on them has been studied. It is shown that the dynamic mode of solvent replacement in two-component hydrogels can reduce the duration of the process by six times and significantly reduce the consumption of acetone compared to the solvent replacement in static mode, as well as preserve the developed porous structure of the material. The specific surface area of organic ALNa-HT and LSNa-HT aerogels is 100 and 260 m2/g, and the carbon aerogels obtained from them are 438 and 868 m2/g, respectively. Scanning electron and atomic force microscopy methods have established that the supramolecular structure of synthesized organic and carbon aerogel nanomaterials is a cluster.
doi:10.34984/SCFTP.2022.17.3.005
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7.0.100-2018
The influence of the structure of biopolymers on the morphology of organic and carbon aerogel nanomaterials based on them / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 37-50. - DOI:
TRANSLIT
Vliyanie struktury biopolimerov na morfologiyu organicheskih i uglerodnyh / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 37-50. - DOI:
En
The influence of the structure of biopolymers on the morphology of organic and carbon aerogel nanomaterials based on them. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 37-50 (2022). https://doi.org/
Key words: anisole, deoxygenation, supercritical hexane, aromatic hydrocarbons
The influence of temperature, pressure and composition of the gas phase on the process of deoxygenation of anisole in supercritical n-hexane in the presence of a palladium catalyst deposited on super-crosslinked polystyrene is investigated. The maximum yield of aromatic products (benzene and toluene) was obtained under the following conditions: temperature 270 °C, initial pressure of the nitrogen—hydrogen mixture (20 vol. % H2) 1.5 MPa.
doi:10.34984/SCFTP.2022.17.3.006
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ГОСТ
7.0.100-2018
Influence of conditions on the process of anisole deoxygenation in supercritical n-hexane in the presence of a palladium catalyst / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 51-59. - DOI:
TRANSLIT
Vliianie uslovii na protsess deoksigenatsii anizola v sverkhkriticheskom n-geksane v prisutstvii palladievogo katalizatora / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 51-59. - DOI:
En
Influence of conditions on the process of anisole deoxygenation in supercritical n-hexane in the presence of a palladium catalyst. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 51-59 (2022). https://doi.org/
Key words: tetra-n-octylamide of diglycolic acid, supercritical fluid extraction, carbon dioxide, water, nitric acid, interphase equilibria
Data on the solubility of diglycolic acid tetran-n-octylamide (TODHA) in supercritical (SC) carbon dioxide at 310-360 K and a pressure of 80-250 bar were obtained. The influence of the presence of an aqueous phase containing nitric acid on the solubility of TODGA in SC-CO2 has been studied. It is shown that the equilibria in the TODGA—water—nitric acid—CO2 system depend in a complex way on the content of each component in it and the state parameters. The patterns characteristic of the TODGA—SC-CO2 dual system cannot be transferred to the four-component TODGA—water—nitric acid—CO2 system, since the presence of highly polar water and nitric acid in it has a critically strong effect on the transition of TODGA to the fluid phase, despite the very low solubility in the structure of these compounds.
doi:10.34984/SCFTP.2022.17.3.007
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ГОСТ
7.0.100-2018
Еquilibria in the system of tetra-n-octylamide of diglycolic acid—water—nitric acid— carbon dioxide / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 60-77. - DOI:
TRANSLIT
Ravnovesiia v sisteme tetra-n-oktilamid diglikolevoi kisloty voda azotnaia kislota dioksid ugleroda / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 60-77. - DOI:
En
Еquilibria in the system of tetra-n-octylamide of diglycolic acid—water—nitric acid— carbon dioxide. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 60-77 (2022). https://doi.org/
Key words: decalin, carbon dioxide, phase equilibrium, solubility, thermodynamic model, Peng-Robinson equation
When studying the phase equilibrium of the decalin-carbon dioxide binary system carried out at isotherms 313 and 333 K and in the pressure range of 2-15 MPa using a high-pressure optical cell, type II phase behavior was established. The experimental results are described using the Peng-Robinson equation of state.
doi:10.34984/SCFTP.2022.17.3.008
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ГОСТ
7.0.100-2018
Phase equilibrium of the decalin—carbon dioxide binary system / – Текст : непосредственный // Сверхкритические Флюиды: Теория и Практика.. – 2022. – Т. 17. – № 3. – С. 78-87. - DOI:
TRANSLIT
Fazovoe ravnovesie binarnoj sistemy dekalin—dioksid ugleroda / – Sverhkriticheskie Flyuidy: Teoriya i Praktika.. – 2022. – Т. 17. – № 3. – S. 78-87. - DOI:
En
Phase equilibrium of the decalin—carbon dioxide binary system. Sverhkriticheskie Flyuidy: Teoriya i Praktika, 3, 78-87 (2022). https://doi.org/