Fine Chemical Technologies (E-Journal) / Тонкие химические технологии
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КИНЕТИКА ПРОЦЕССА ОКИСЛИТЕЛЬНОГО ХЛОРИРОВАНИЯ МЕТАНА
Get PDFHeterogeneous oxidative chlorination of methane was investigated. The target product is methyl chloride. The investigated terms and conditions of oxychlorination of methane: process temperature 400°C, pressure 0.1-0.9 MPa, catalyst (% weight.): copper chloride (II) 1-8%; potassium chloride 2.5%; lanthanum chloride 1%; carrier - aluminosilicate. Powder X-ray diffractometry and electron microscopy showed that the active catalyst components (CuCl2, KCl, LaCl3) are unevenly distributed on the support surface (α-Al2O3·SiO2) and form agglomerates with a high salt content, including binary chlorides such as KCuCl3, K2CuCl3 or K2CuCl4, hydrates K2CuCl4·2H2O and CuCl2·2H2O and hydroxychlorides Cu3Cl4(OH)2 and Cu2Cl(OH)3. The kinetics of methane oxychlorination was studied in a gradientless reactor at 400°C and pressure 0.1 - 0.9 MPa by varying the partial pressures of the reactants. Analysis of the products was carried out by GC. An equation of the reaction rate including partial pressures of methane, hydrogen chloride and water to the 0.77, 0.01 and 0.64 power, respectively, but of zero order by oxygen and chlorine provides an adequate description of methyl chloride formation rate. Significant influence of water partial pressure is proved for the reaction under consideration
МОДИФИКАЦИЯ ЭПОКСИДНЫХ ПОЛИМЕРОВ НАНОДИСПЕРСНЫМ ОКСИДОМ АЛЮМИНИЯ
Get PDFThe aim of this work was to improve the physical, chemical and mechanical properties of epoxy composites with the use of nanosized aluminium oxide. The studies proved the possibility of directional control of the operational properties of epoxy composites by the use of small additions of nanosized aluminium oxide ensuring the creation of epoxy composites with high performance, satisfying the requirements of most industries. The rational content of aluminium oxide as a nanostructuring additive in an epoxy composition was selected (0,05 parts by weight). It ensures an increase in the complex of physico-mechanical properties (the breaking stress increases 3.3-fold, and the flexural modulus increases by 27%, the breaking stress in compression improves by 43%, the breaking stress and the tensile modulus of elasticity increases by 47-50%, the toughness increases 3-fold, and the hardness increases by 67%), while maintaining heat resistance. The introduction of nanosized aluminium oxide changes the parameters of the epoxy oligomer curing kinetics: the gelation duration increases from 45 to 75 minutes, and the duration of cure, from 53 to 100 minutes, while the maximum curing temperature is practically unchanged. Thus, the developed materials may be used for sealing electronic articles, for impregnating and filling components in aircraft engineering, shipbuilding and, automotive industry
ПЕРЕРАБОТКА ОТХОДОВ ТЕЛЛУРИДА ВИСМУТА
Get PDFThe main stages of bismuth telluride processing comprising sintering with NaOH, leaching and precipitation were investigated. Bi2Te3 samples produced by "ADV Engineering" were used as starting compounds. The studies revealed regularities of tellurium behavior during the sintering of Bi2Te3 with NaOH and the resulting the solid residue leaching. It was noted that annealing at 350-450°C with NaOH transforms tellurium into Na2TeO3, which is an appropriate form for further dissolution and separation from bismuth. Increasing temperature results in Na2TeO3 oxidation and formation of the water-insoluble compound Na2TeO4. Thus, it decreases tellurium extraction degree during the leaching. It has been shown that increasing temperature from 8 to 25°C at the step of tellurium hydrolytic precipitation slightly affects the extraction degree, the value of which is 93.5-98.2%.В работе исследованы основные стадии переработки теллурида висмута Bi2Te3, включающие: спекание с NaOH, выщелачивание и гидролитическое осаждение. В качестве исходных веществ использованы образцы ООО «АДВ Инжиниринг». В результате проведенных исследований выявлены закономерности поведения теллура на стадии спекания Bi2Te3 с NaOH и выщелачивания полученного спека. Отмечено, что при температуре 350-450°С на стадии спекания с NaOH теллур переходит в форму Na2TeO3, удобную для дальнейшего извлечения в раствор и отделения от висмута. Увеличение температуры приводит к окислению Na2TeO3 и образованию Na2TeO4 - соединения, не растворимого в воде, и тем самым - снижению степени извлечения теллура на стадии выщелачивания. Показано, что увеличение температуры от 8 до 25°С на стадии гидролитического осаждения теллура практически не влияет на степень его извлечения, которая составляет 93.5-98.2%
ЗАКОНОМЕРНОСТИ ЭТЕРИФИКАЦИИ ГЛИЦЕРИНСОДЕРЖАЩИХ ОТХОДОВ ПРОИЗВОДСТВА БИОДИЗЕЛЯ ДЛЯ ПОЛУЧЕНИЯ ПЛАСТИФИЦИРУЮЩИХ КОМПОЗИЦИЙ
Get PDFKinetics of catalytic esterification of glycerol with butanoic acid on model systems was studied. Reaction orders for the reactants (butanoic acid and glycerol) were determined. They are close to 1.It was shown that the reaction order with respect to the catalyst - orthophosphoric acid - in regions where its concentration is above 0.1 mol/l is equal to zero. The estimated value of activation energy is 51.9± 8.0 kJ/mol. The results of the experiment can be used to create an industrial technological process for the synthesis of glycerol tributyrate. This compound can be used as an alternative non-phthalate plasticizer for articles made of PVC. The obtained kinetic model was validated on glycerol-containing waste of the biodiesel synthesis from renewable raw materials. The recycling of the by-product in the biofuel production with obtaining plasticizing compositions for the polymer industry can be developed on the basis of the studies.В работе на модельных системах исследована кинетика каталитической этерификации глицерина бутановой кислотой. Определены порядки реакции по реагентам (бутановая кислота, глицерин), которые близки к единице. Показано что в областях концентрации катализатора более 0.1 моль/л, порядок по нему равен нулю. Оценено значение наблюдаемой энергии активации, которое составило 51.9±8.0 кДж/моль. Результаты эксперимента позволяют рекомендовать условия для создания технологии промышленной реализации процесса синтеза трибутирата глицерина, который может быть использован в качестве альтернативной нефталатной пластифицирующей композиции для изделий из ПВХ. Полученная кинетическая модель проверена на глицеринсодержащих отходах процесса синтеза биодизеля из возобновляемого сырья, что позволяет предложить способ утилизации побочных продуктов при производстве биотоплива с получением технически востребованного продукта для полимерной промышленности с высокой добавленной стоимостью
О ТЕРМИЧЕСКОЙ УСТОЙЧИВОСТИ КОМПЛЕКСА ВИСМУТ(III) ЙОД ЭТИОПОРФИРИН II
Get PDFFor the first time, a complex of bismuth(III) with iodine and etioporphyrin II is reported. It was prepared by reacting etioporphyrin II and bismuth(III) iodide in pyridine in Ar atmosphere. The prepared compound was characterized by FT-IR, 1H-NMR, UV-VIS spectroscopy and mass spectrometry. One intense line at m/z 684.990 attributed to the complex without the iodine atom is observed in the mass spectrum. This is in agreement with the data indicating that bismuthporphyrin complexes generally have low stability. Analysis of FT-IR spectra obtained at room temperature and at 145°С is reported. Priroda15 DFT package was used for optimization of complex geometry and calculation of the IR spectrum. Calculations were done using BPE functional and L1 basis set under relativistic approximation of Dyall Modified Dirac. Assignment of the vibrational frequencies is reported. Collected data indicate that the complex of bismuth(III) with iodine and etioporphyrin II is not stable and easily hydrolyses when exposed to air forming the corresponding hydroxocomplex. This transformation does not change significantly the dynamics of the porphyrin ring
РАЗДЕЛЕНИЕ СМЕСЕЙ ПУТЕМ СОЧЕТАНИЯ ПРОЦЕССОВ РЕКТИФИКАЦИИ И ФРАКЦИОННОЙ КРИСТАЛЛИЗАЦИИ
Get PDFVarious options of separation of binary mixtures by combining the processes of fractional crystallization and rectification are considered. The base mixture, depending on its composition, can be initially directed to the rectification stage or to one of the stages of separated components crystallization using the proposed variants. The flow diagrams of integrated heat exchanging systems and schemes involving open and closed type heat pumps under consideration for the determination of ways of reducing energy consumption of the coupled processes were suggested. These solutions enable improving the processes energy efficiency. In addition, the analysis of the effect of the composition and temperature of the initial mixture, the temperature of fractionation at the crystallization stage, the composition of distillates and bottom products on the separation parameters was carried out. It was found that when the initial mixture is fed to the stage of crystallization of one of the components, the energy costs for carrying out the process under consideration are usually lower than when the initial mixture is fed to the rectification stage. It is shown that using a combination of fractional crystallization and rectification processes can significantly expand the possible separation range and improve the technical and economic characteristics of the separation process
СТРУКТУРНАЯ ДИНАМИКА СВОБОДНЫХ МОЛЕКУЛ И КОНДЕНСИРОВАННОГО СОСТОЯНИЯ ВЕЩЕСТВА. Часть I. ТЕОРИЯ И ЭКСПЕРИМЕНТАЛЬНЫЕ МЕТОДЫ
Get PDFTo understand the dynamic features of molecular systems with a complex landscape of potential energy surfaces, it is necessary to study them in the associated 4D space-time continuum. The introduction of time in the diffraction methods and the development of coherent principles of the research process opened up new approaches for the study of the dynamics of wave packets, intermediates and transient states of the chemical reactions, short-lived compounds in the gaseous and condensed media. Time-resolved electron diffraction, the new method for the structural dynamic studies of free molecules, clusters and condensed matter, differs from the traditional method of electron diffraction both in the experimental part and in the theoretical approaches used in the interpretation of diffraction data. Here there is particularly pronounced the need of a corresponding theoretical basis for the processing of the electron diffraction data and the results of spectral investigations of the coherent dynamics in the field of intense ultrashort laser radiation. Such unified and integrated approach can be formulated using the adiabatic potential energy surfaces of the ground and excited states of the systems under study. The combination of state-of-the-art optical techniques and electron diffraction methods based on different physical phenomena, but complementing each other, opens up new possibilities of the structural studies at time sequences of ultrashort duration. It provides the required integration of the triad, "structure - dynamics - functions" in chemistry, biology and materials science
ТЕРМОХИМИЧЕСКИЙ СИНТЕЗ И ЛЮМИНЕСЦЕНТНЫЕ СВОЙСТВА НАНОСТРУКТУРИРОВАННЫХ ПОРОШКОВ Y2O3:Eu3+ И Y2O3:Bi3+, Eu3+
Get PDFСТРУКТУРНАЯ ДИНАМИКА СВОБОДНЫХ МОЛЕКУЛ И КОНДЕНСИРОВАННОГО СОСТОЯНИЯ ВЕЩЕСТВА. Часть II. ПЕРЕХОДНЫЕ СТРУКТУРЫ В ХИМИЧЕСКИХ РЕАКЦИЯХ
Get PDFBasic knowledge of mankind so far relates to the description of electrons and atoms in the material in a state of equilibrium, where the behavior changes slowly over time. The electron diffraction with a high temporal and space resolution has opened the possibility of direct observation of the processes occurring in the transient state of the substance (molecular movie). Here it is necessary to provide a temporary resolution of the order of 100 fs, which corresponds to the transition of the system through the energy barrier of the potential surface, which describes the chemical reaction - the process of the breaking and the formation of new bonds between the interacting agents. Thus, the possibility of the investigation of the coherent nuclear dynamics of molecular systems and the condensed matter can be opened. In the past two decades, it has been possible to observe the nuclear motion in the temporal interval corresponding to the period of the nuclear oscillation. The observed coherent changes in the nuclear system at such temporal intervals determine the fundamental shift from the standard kinetics of chemical reactions to the dynamics of the phase trajectory of a single molecule, the molecular quantum state tomography
ИДЕНТИФИКАЦИЯ ГИБРИДНОГО БЕЛКА ЭПО-Fc МЕТОДАМИ ПОЛИАКРИЛАМИДНОГО ГЕЛЬ-ЭЛЕКТРОФОРЕЗА С ИЗОЭЛЕКТРИЧЕСКИМ ФОКУСИРОВАНЕИМ (IEF-PAGE) И В ПРИСУТСТВИИ ДОДЕЦИЛСУЛЬФАТА (SDS-PAGE)/ЛАУРИЛСАРКОЗИНАТА НАТРИЯ (SAR-PAGE) С ЦЕЛЬЮ АНТИДОПИНГОВОГО КОНТРОЛЯ
Get PDFThe article is devoted to develop of an approach for the identification of new stimulator of ematopoiesis, EPO-Fc fusion protein, which is banned by the World Anti-doping Agency (WADA) to use by athletes since it has become doping. Existing methods of qualitative determination of this substances in routine practice of antidoping laboratories such as polyacrylamide gelelectrophoresis in presence of sodium dodecylsulphate (SDS-PAGE) or lauroylsarcosinate (SARPAGE) are insufficiently specific. The article shows the principal possibility of identification of EPO-Fc fusion protein by means of IEF-PAGE in carrier ampholyte-based gels with a pH range 2-6 after Fc-fragment removal via fermentative hydrolysis.It has been shown that the removing of the crystallizable fragment leads to decrease of molecular weight of whole hybrid molecule and to increase its electrophoretic mobility that allows to detect this banned substances with high specificity by existing methods. During the study the enzyme for hydrolytic cleavage and optimum conditions of hydrolysis of EPO-Fc in serum samples were selected