Theoretical Foundations of Chemical Engineering最新文献

{"title":"The Effect of Na, Si, and P on the Phase Composition of Zirconium and Sodium Silicophosphates (NASICON)","authors":"D. N. Grishchenko,&nbsp;M. A. Medkov","doi":"10.1134/S0040579524700428","DOIUrl":"10.1134/S0040579524700428","url":null,"abstract":"<p>The effect of the excess of Na, Si, and P on the composition of Na_{1 +} _<i>x</i>Zr₂P_{3 –} _<i>x</i>Si_<i>x</i>O₁₂ (0 ≤ <i>x</i> ≤ 3) silicophosphates is studied; the samples are obtained by the pyrolysis of organic solutions in a rosin melt. The samples are studied by x-ray diffraction analysis, scanning electron microscopy, and the Rietveld method. It is established that specific concentrations of Na, Si, and P additives affect the impurity content in the synthesis products and change the phase composition of Na_{1 +} _<i>x</i>Zr₂P_{3 –} _<i>x</i>Si_<i>x</i>O₁₂.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 2","pages":"261 - 265"},"PeriodicalIF":0.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rates of Formation of Silaethylene and the Methyl and Silyl Radicals by the Pyrolysis of Methylsilane","authors":"D. V. Sidorov,&nbsp;A. D. Kirilin,&nbsp;A. A. Shavnev","doi":"10.1134/S0040579524700519","DOIUrl":"10.1134/S0040579524700519","url":null,"abstract":"<div><p>A quantum chemical study of the rates of chemical reactions of formation of silaethylene and the methyl and silyl radicals by the pyrolysis of methylsilane in the gas phase was performed. The geometry and thermodynamic characteristics of the compounds participating in the chemical reactions were calculated by an ab initio method according to the second-order Møller–Plesset perturbation theory with the 6–31+G basis set at temperatures up to 2700 K. The equilibrium constants and rates of the studied reactions were calculated, and so were the pre-exponential factor and activation energy for the Arrhenius equation.</p></div>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 2","pages":"308 - 315"},"PeriodicalIF":0.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of Radiation Effect on the Process Parameters upon Extraction of Cm and Am by Displacement Complexation Chromatography","authors":"O. V. Kharitonov,&nbsp;L. A. Firsova","doi":"10.1134/S0040579524700313","DOIUrl":"10.1134/S0040579524700313","url":null,"abstract":"<div><p><b>Abstract</b>—Radiation loads on the sorbent and eluent upon extraction of Cm and Am by displacement complexation chromatography from complex-composition solutions using an eluent containing DTPA and citric acid are calculated. The destruction of the eluent and sorbent in the columns is estimated. Good agreement is obtained between the calculation and experimental data on the concentrations and rate of curium band motion through the column.</p></div>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 1","pages":"182 - 187"},"PeriodicalIF":0.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Possibility of Using Silicon Dioxide Obtained from Mineral Raw Materials as an Enterosorbent","authors":"D. V. Maiorov,&nbsp;Yu. O. Velyaev","doi":"10.1134/S0040579524700209","DOIUrl":"10.1134/S0040579524700209","url":null,"abstract":"<div><p>Samples of amorphous silicon dioxide (SiO₂) are obtained by acidic decomposition of mineral raw materials (nepheline). The physicochemical and structural surface properties of the samples are studied using chemical and granulometric analyses and the BET and BJH methods. It is established that the obtained SiO₂ samples are almost identical to pyrogenic amorphous silicon dioxide obtained from reactive raw materials (pharmaceutical remedy Polysorb MP) in impurity content and have higher specific external surface area (by a factor of 1.1–1.9) and specific pore volume (by factor of about 1.4) compared to Polysorb MP. An economic assessment of their production cost is performed, which shows that the cost of silicon dioxide obtained by the developed technologies is more than two times lower than the cost of commercial pyrogenic silicon dioxide that is present in the market. Based on the obtained results, we discuss the prospects of using silicon dioxide obtained on the basis of acidic treatment of mineral raw materials as an enterosorbent in therapeutic practice.</p></div>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 1","pages":"101 - 108"},"PeriodicalIF":0.7,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving the Energy Efficiency of an Oil Treatment and Stabilization Plant at the Field","authors":"L. M. Ulyev,&nbsp;M. T. Kuznetsov,&nbsp;T. A. Gil,&nbsp;V. V. Norin,&nbsp;A. A. Saitova,&nbsp;E. V. Kuvardina","doi":"10.1134/S0040579524601286","DOIUrl":"10.1134/S0040579524601286","url":null,"abstract":"<p>The energy intensity of the Russian economy is 1.5–2 times higher than the similar indicator of developed countries such as the USA, the countries of the European Union, and China. First of all, this is due to the low percentage of thermal energy returned to the process, which leads to excess consumption of fuel and power, and, consequently, to increased consumer costs of end products and additional greenhouse gas emissions. This problem is relevant for the oil, gas, and gas condensate fields of the Russian Federation, where the commercial product is often used as fuel to provide heat and power to both the field itself and the subsequent oil preparation and stabilization unit. However, this problem can be successfully solved using modern process-integration tools such as pinch analysis. In this study, the structure of the heat-exchange network of the oil preparation and stabilization unit is optimized in order to reduce its energy consumption and impact on the environment. The installation under study consists of a settling tank, an electric dehydrator, an oil-stabilization column, and a light hydrocarbon compression station. It is found that the current energy consumption of the plant for hot utilities is 387 MW, and for cold utilities 214 MW. Moreover, these values can be reduced by 214 MW by changing the topology of the heat-exchange network. This corresponds to a reduction in fuel consumption of 55% and power consumption of 1067 kW. In addition, this approach allows for a reduction in CO₂ emissions by 453 000 t/year.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"708 - 714"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical Description of the Process of Impact Interaction of a Flow of Catalyst Particles with a Breaking Element in a Cyclone Device with a Coaxial Arrangement of Purification Stages","authors":"A. E. Lebedev,&nbsp;M. A. Yurovskaya,&nbsp;I. S. Gudanov,&nbsp;V. K. Leontiev","doi":"10.1134/S0040579524601237","DOIUrl":"10.1134/S0040579524601237","url":null,"abstract":"<p>Processes for cleaning solid particles from gases are used in many modern enterprises. Among the main requirements for gas-cleaning equipment are high purification degree, small overall dimensions, low hydraulic resistance, and ease of maintenance. All these requirements are met by a cyclone apparatus with a coaxial arrangement of cleaning stages, developed at Yaroslavl State Technical University. In this apparatus, three stages of purification of the dust and gas flow are arranged sequentially. At the first and third stages, the separation of solid particles from the gas flow occurs due to centrifugal force, and at the second stage, inertial settling of particles is effectuated. In addition, the first stage of the apparatus is equipped with a baffle element, which not only increases the efficiency of solid-phase separation, but also makes it possible to destroy the formed agglomerates due to the organization of impact interaction. The processes of centrifugal and inertial separation, implemented at the second and third stages of the apparatus, are currently studied almost completely, whereas the impact interaction of the particle flow with the baffle element remains poorly understood. In this paper, on the basis of a probabilistic approach, expressions are obtained for the differential distribution function of the number of particles of the solid phase captured by the centrifugal-impact stage of the cyclone apparatus with a coaxial arrangement of purification stages. Experimental studies have confirmed the adequacy of the formulated expressions for the average particle size. Thus, the obtained expressions for the differential distribution function of the number of particles make it possible to estimate the composition of the solid phase separated at the first stage and carried away with the gas flow to the second and third, which is necessary when drawing up an engineering method for calculating the apparatus.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"666 - 669"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterophasic Concentrating of Tritium Oxides","authors":"Ya. O. Shablovsky","doi":"10.1134/S0040579524601304","DOIUrl":"10.1134/S0040579524601304","url":null,"abstract":"<p>Recycling of tritiated wastewater provides tritium products of high practical and commercial value. The recycling process includes three stages: (1) conditioning (preliminary enriching) of raw tritiated water by means of reverse osmosis; (2) concentrating the tritium oxide by means of salt rectification of the tritiated water; (3) obtaining tritiated ice. The paper presents the technological conditions for each stage with special attention paid to the opportunity of producing helium-3 as the final product of tritiated wastewater recycling.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"692 - 697"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical Model of Moisture and Current Transfer through the Stem Wall during the Electroosmotic Dehydration of Plant Materials","authors":"A. A. Bagaev","doi":"10.1134/S0040579524601201","DOIUrl":"10.1134/S0040579524601201","url":null,"abstract":"<div><p>A topical issue in the harvesting of forage grasses is to preserve the nutrients in the harvested forage and reduce the cost of its production. An efficient means to solve this problem is provided by the processes of electrotechnology, where the working body is strong electrical fields. In such electrotechnological processes as electro-osmosis and electroplasmolysis, the plant material is an element of an electrical circuit, in which the electrophysical properties of the processed object can be reasonably simulated by an electrical equivalent substitution circuit. The elements and configuration of the substitution circuit and the main directions of increasing the energy efficiency of the electrotechnological processes can be substituted via analysis of the physical processes in the stem wall of forage grasses. The goal of this study was to establish the analytical relationship between the rate of moisture and electrical current transfer through the stem wall of plant tissue for implementation in electrotechnological processes in agriculture applications. The object of study is the stem wall of forage grasses (<i>Bromus inermis</i>). The main provisions from the theory of electrotechnology, biophysics, electrochemical kinetics, ion exchange, and electrochemical alternating current circuits are used. The mathematical model establishes the relationship between the process of moisture transport through the plant tissue in the transverse direction under the influence of electrical current. The stages of current and moisture transfer through the stem wall are considered by using a stem wall selected arbitrarily from a grass mass as an example with consideration for the adopted assumptions and the presumed distribution of electrical potentials at the phase interface. The role and place of the technological component of the current through the plant tissue wall are established. The set of derived equations describing the process of moisture transfer through the plant tissue in the transverse direction under the influence of electrical current determines the prerequisites for the synthesis of a substitution circuit. The ways of increasing the technological component of the current are determined. Improving the efficiency of electrotechnological processes in the processing of plant materials (in particular, electroosmotic dehydration) should be considered as a process of increasing the share of the technological component of “direct” current in the total current and decreasing its thermal effect.</p></div>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"651 - 656"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation of the Limiting Pore Diameter Qualifying the Pore as a Capillary Under Conditions of Centrifugal Drying of Sediments","authors":"V. G. Zhukov,&nbsp;V. M. Chesnokov,&nbsp;N. D. Lukin","doi":"10.1134/S0040579524601225","DOIUrl":"10.1134/S0040579524601225","url":null,"abstract":"<p>Mechanical drying in the rotating rotor of a filtering centrifuge is accompanied by the formation of a capillary rim, an annular layer of pores of the sediment upstream of the filtering surface. The rim of adjacent chains of pores, which are filled with the filtrate and tend to a radial arrangement, limits the decrease in the moisture content of the sediment. Consideration is made of a statistically ordered pore space of the sediment in which chains of communicating pores of each size can form. The rim includes a filtrate-unsaturated inner annular layer with a branched structure in the form of a fringe on the side of the rotor and may include a filtrate-saturated outer bottom layer adjoining the filtering surface. The filtrate filling each chain of pores ends at both ends with menisci. The larger the diameter of pores, the shorter their chain filled with the filtrate. The condition under which only menisci remain in the largest pores is considered. The diameter of such pores is called the limiting diameter. If the sediment contains pores whose size exceeds the limiting diameter, then even menisci cannot form in them, and chains of such pores will remain unfilled. In the rim, through channels appear, through which the air flow circulates, enhancing the drying of the sediment in the rotating rotor. The purpose of the study was to obtain an analytical formula for calculating the limiting diameters of pores in sediments in filtering centrifuges. A formula for calculating the limiting diameter was obtained. This formula also allows determining the operating parameters of the centrifuge to control the limiting diameter up to the disappearance of the bottom layer and the occurrence of a ventilation effect. An example of calculation was performed. It showed the possibility of the appearance or disappearance of the bottom layer by selecting the angular velocity and the radius of the filter surface. This creates practical opportunities for the calculation-assisted control of the moisture created by the capillary rim either by organizing a ventilation effect through the thickness of the sediment with its thermodynamic drying, or by creating a bottom layer preventing ventilation to maintain a certain moisture content.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"715 - 720"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of the Temperature of Single-Bubble Sonoluminescence in Various Liquids From Color Images","authors":"S. P. Pronin,&nbsp;R. B. Mindibaev","doi":"10.1134/S0040579524601250","DOIUrl":"10.1134/S0040579524601250","url":null,"abstract":"<p>Determining the content of various substances in solutions by sonoluminescence spectroscopy is an urgent task. The temperature in the sonoluminescence bubble has a significant influence on the measurement of the concentration of substances. When measuring temperature, the method of spectral pyrometry is used. An alternative option is to estimate the temperature by the RGB components in a color image. The subject of the study is the temperature in a luminous sonoluminescence bubble. The aim of the work is to create an experimental setup, obtain glowing bubbles, fix images of the bubbles, and estimate the temperature by the RGB components. The experimental setup is based on a 250 mL round-bottomed flask with piezoceramic emitters. The temperature assessment is carried out according to the following algorithm: recording a color image of the bubble, decomposing the image into RGB components, determining the histograms and medians in each component, calculating the median contrast, and estimating the temperature by contrast. Four liquids are used in the experiment: distilled water for injection, spring water from the village of Srostki in the Altai krai, distilled water for batteries, and distilled water saturated with argon. In the bubbles of the first three liquids, the temperatures are 5984, 5340, and 5351 K. A bubble in the distilled water saturated with argon shows a temperature of 12 120 K. The created experimental setup makes it possible to obtain stable single-bubble sonoluminescence in various liquids. The developed technique for estimating the temperature inside single-bubble sonoluminescence by median contrast can be used in experimental studies.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 3","pages":"677 - 684"},"PeriodicalIF":0.7,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}