The process of desorption of corrosive dissolved gases from water by air during CO2 removal and by water vapor during O2 deaeration was investigated. The article briefly discusses approaches to mathematical modeling of mass transfer in packed desorbers with irregular contact devices (chaotic packings) at film counterflow of gas and liquid. To reduce the complexity and time of mathematical modeling, a cellular model of the hydrodynamic structure of flows is presented. An expression is obtained for calculating the efficiency of extraction (mass transfer) of dissolved gases, where the main parameters are the volumetric mass transfer coefficient and the number of complete mixing cells. For a given mass transfer efficiency, the required height of the packed layer is written from this expression. Calculations of CO2 desorption from water by air in columns with Raschig and Pall rings, Intalox saddles, as well as with GIAP and Inzhekhim nozzles with a nominal size of 25-80 mm and a specific surface of 70-185 m2/m3 were performed. Tables are given with experimental and calculated coefficients of mass transfer, nozzle height and pressure drop at an irrigation density of 50-100 m3/(m2 h). Conclusions are drawn about the influence of the flow structure on the efficiency of mass transfer depending on the flow rate of the liquid phase and the design of the nozzles. A histogram is given with the calculated values of the height of the packed layer and the pressure drop at an efficiency of CO2 extraction from water of 99% for the considered packing designs. The introduction of a chaotic Inzhekhim nozzle in a thermal deaerator at a water treatment plant at a thermal station was noted. The presented expressions for determining the efficiency of mass transfer can be used in engineering calculations of packed desorbers of sparingly soluble gases in counterflow.

A procedure was developed for preparing polyphenylene sulfide with low melt viscosity by liquid-phase polycondensation at pH > 12 with stepwise heating from 160 to 220°С in the prepolycondensation step and from 230 to 260°С in the afterpolycondensation step. The polyphenylene sulfide melt flow index can be varied from 300 to 18 g/10 min by stepwise variation of the Na2S excess and temperature in the course of polyphenylene sulfide polycondensation. The optimum time of the polyphenylene sulfide synthesis was 16 h. The polyphenylene sulfide exhibits the physicomechanical properties similar to those of Ryton@ XE5500BL thermoplastic (Solvay) but is characterized by 50

A unit for separating heavy vacuum gas oil of a stabilized composition from a wide fraction of vacuum gas oil with a capacity of 65,000 tons per year is designed and implemented at an industrial enterprise. Technical solutions, as well as the results of operating the unit, are described. Experimental studies into technological modes are carried out using a laboratory model of the distillation column. A previously developed mathematical model of multicomponent distillation is used to calculate an industrial column with a new regular packing, where the mixture is represented as pseudo-binary in terms of fractions. In addition, software packages for plate-by-plate calculations of the column are applied. The main and auxiliary equipment for the developed vacuum distillation unit is selected.

The paper presents the results of an experimental study of phase equilibrium characteristics for hexadecane–propane/butane and sulfur–propane/butane systems. It also contains data on the kinetics of hydrocarbon extraction from asphaltene-resin-paraffin deposits and states that it is advantageous to apply SCF-extraction (in contrast to liquid extraction) to clean oil wellheads.

The sugar industry in Russia plays a huge role in ensuring the country’s food security and is a strategic industry. Of the 90 sugar factories in Russia today, a third of the factories are closed due to unprofitability associated with the high cost of sugar production due to low feed capacity. The raw material for sugar production is sugar beet, mainly domestically produced. The locations of most sugar factories are small municipalities, for which they are the town-forming enterprises. For the revival of closed sugar factories, it is necessary to increase their capacity, which is difficult to do due to the fact that in the diffusion section of each sugar factory there is one large-sized imported diffusion apparatus of a mechanical type, which does not allow increasing capacity in any other way than purchasing a new, more high-performance expensive imported diffusion apparatus of a mechanical type. In the current conditions of uncertainty and disruption of trade relations with other countries, new suppliers of high-performance diffusion apparatus are needed in Russia itself, the apparatus of which would at least not be inferior to the Western apparatus. The Russian company Ingehim has developed a diffusion pulsating apparatus (DPA) without mechanical movable transporting devices, which reduces energy consumption, operating costs and lowers quality requirements for sugar beet chips. The test results obtained using an experimental unit showed a higher quality of the diffusion juice. The lightness of the juice was found to be much higher compared to juices produced in conventional diffusion apparatus, and the juice purity was found to be 5% higher at a comparable solids content, resulting in an additional amount of sugar produced per year, allowing for a faster return on investment.

Chicory roots are a valuable source of inulin and other healthy nutrients. The most common direction of their industrial processing is instant chicory powder production. Extraction is the main process in the production. Conventional extraction methods, which include maceration, percolation and extraction in a screw extractor, have a number of significant drawbacks, including high capital and operating costs, low quality of the resulting extract, complexity in repairing equipment, short overhaul life, etc. The purpose of the present study was to assess the technical feasibility of increasing extraction process efficiency through using continuous pulsating extractors (CPE) developed by the Ingehim company, in which a non-stationary, countercurrent mode of interaction of raw materials with the extractant is incorporated. Testing of engineering solutions implemented in CPE was carried out at a pilot pulsating unit (PPU). For extraction, roasted and crushed (5–20 mm) chicory roots from one of the operating chicory factories were used. The ratio chicory : water during extraction was 1 : 4.5, which is 1.5–2.5 times lower than in conventional extractors. A lower extraction temperature (up to 85°C) combined with a shorter extraction time (up to 1 hour) may help retain more inulin and other nutrients as compared to conventional methods. The results of the study at the PPU under these conditions confirmed the high yield of water-soluble solids (up to 98%) without additional grinding. A scheme for the modernization of a chicory factory equipped with the most common percolation extraction equipment having a feed capacity of 400 kg/h is proposed through using CPE. 3D images of the proposed modernization are shown. A comparative assessment of energy consumption for extraction using different methods is given. The results of the study indicate the capability and high efficiency of CPE for extracting chicory, which is confirmed by a decrease of up to 3.6 times in the total specific energy consumption for obtaining 1 kg of instant chicory powder compared to conventional extractors. Low capital and operating costs determine the prospects for using CPE for the modernization of existing chicory factories or the creation of new energy-efficient factories.

A heavy vacuum gas oil separation unit was developed and implemented at an industrial enterprise with a stabilized composition. The technical solutions, the selected equipment and the results of the installation operation are described. On a laboratory model of a distillation column, experiments were made to develop technological conditions. In calculations of an industrial column with a new regular packing applied previously developed mathematical model of multicomponent distillaton. The mixture is represented as pseudo-binary in terms of fractions. In addition, software packages for plate-by-plate calculation of the column. The selection of the main and auxiliary equipment of the industrial vacuum distillation plant was carried out.

With the aim of increasing the capacity of commercial cooling towers and enhancing heat-transfer processes, the authors have developed a structure of a jet-film contact device. An experimental setup was assembled that permits investigating the hydrogasdynamics of a liquid in the operating region of the device. Results of investigation into the influence of the flow rate of the liquid and the gas on the hydraulic resistance of the contact device have been presented. A mathematical dependence has been obtained for calculating the pressure difference of a dry packing of the jet-film contact device on the velocity factor. It has been established that with increase in the water concentration, the hydraulic resistance changes only slightly, which is a great advantage among the existing structures. The heat output of a cooling tower has been determined; the criterion of energy efficiency has been considered which takes account of the expenditure of energy to pump air. The high energy efficiency of a jet-film contact device compared to various types of water-cooling devices has been proved.

The process of removing corrosive gases from water at TPPs in packed columns of calciners and in columns of thermal deaerators with a storage tank in film mode is considered and a mathematical model is presented for calculating the efficiency of the desorption process. A cell model of the flow structure and an equation for calculating the mass transfer coefficient for a wave flow of a water film over the surface of a packing with artificial roughness are used. The value of the required height of the packing layer is obtained for the given density of irrigation with water and the efficiency of extracting gases dissolved in water. Formulas are given for calculating the parameters of a mathematical model: the coefficient of mass transfer in the wave film, the average velocity of water in the film, the dynamic retention of the liquid in the packing layer and the number of cells for complete mixing of the liquid phase. The possibility of using metal chaotic and regular packings is considered, and the results of calculations of the efficiency of mass transfer and the required height of the packing layer at various operating parameters of the desorption process are presented. The graphs of the required layer height for the given efficiency of mass transfer and the power spent on air supply to the desorber when using various nozzles of domestic and foreign production are presented. The article describes the operation of a thermal deaerator with a storage tank and outdated contact devices in a deaerator column at a TPP. The main mass transfer and hydraulic characteristics of modern nozzles for thermal deaerators are presented. Technical solutions have been developed that can be used when choosing a highly efficient metal chaotic packing with a rough surface, which provides an increase in the mass transfer coefficient in a liquid wave film and, accordingly, the efficiency of mass transfer. A variant for modernization of the deaeration column of the DSA-300 deaerator at the Kazan CHPP-3 by replacing outdated contact devices with a modern chaotic packing is shown. As a result of its application, compliance with the standards of water purification from dissolved oxygen is ensured at various loads on water and steam.

Приведены результаты экспериментального исследования характеристик фазовых равновесий для систем «гексадекан-пропан/бутан» и «сера-пропан/бутан». Представлены данные по кинетике экстракционного извлечения углеводородов из асфальтосмолопарафиновых отложений и установлено предпочтительное использование СКФ-экстракционного процесса (в противовес жидкостному) для очистки устья нефтяных скважин. The results of an experimental study of the characteristics of phase equilibria for the systems «hexadecane - propane/butane» and «sulfur - propane/butane» are presented. The data on the kinetics of extraction of hydrocarbons from asphalt-resin-paraffin deposits are presented. It has been established that it is preferable to use the SCF-extraction process (as opposed to the liquid one) in relation to the process of cleaning the wellhead of oil wells from asphalt-resin-paraffin deposits.

In this work, we propose an alternative method for the utilization of sleepers, based on the use of a supercritical fluid extraction process. The preference for the implementation of a supercritical fluid extraction process for “extractable-extractant” systems exhibiting I–II types of phase behavior is given. On the example of supercritical fluid extraction of the impregnation material of spent wood railway sleepers, the efficiency of replacing the carbon dioxide participating as an extractant with a propane/butane mixture, which provide the desired change in the type of phase behavior in relation to such components of the impregnation material as phenol, anthracene and naphthalene is shown. The phase equilibria of thermodynamic systems involving carbon dioxide and a propane/butane mixture on the one hand and coal oil components such as phenol, anthracene, and naphthalene on the other are studied. The proposed method of processing spent railway sleepers allows you to select from it up to 97 % of the mass impregnation source material.

A description of the technological scheme of the unit for separating the fraction of vacuum gas oil (FVG) is given, where the process of separation of heavy gas oil from FVG takes place in the column. The main focus of the work is on the design of a distillation column using the new structured roll packing. The fractional composition of the feedstock, by-product, light gas oil, and the target product, which is heavy gas oil, is presented. Requirements for the design of a structured packing in terms of pressure drop and separation efficiency are formulated. A structured roll packing with corrugations and rough surface having specific surface area of 300 m 2 /m 3 is chosen. The diagram and photograph of the packing are presented. Comparative values of specific pressure drop for several structured packings are given. It is shown that the selected packing provides the lowest hydraulic resistance. For mathematical modeling and calculation of the multicomponent distillation process, a system of mass transfer equations with interfacial bulk sources of transfer components is used. In this case, for the conditional component, a fraction at the specified boiling points is used. As a result of solving the system of equations with boundary conditions, the profiles of the fractions along the height of the packed bed are found and the structural characteristics of the structured packing are selected that meet the requirements for the top and bottom of the column. Calculations of a vacuum distillation column with this packing are carried out and it is found that the bed height of 6 meters is sufficient to meet the requirements for the fractional composition of the upper and lower products, while meeting the pressure drop requirements. The developed scientific and technical solutions have been implemented at a refinery in Malaysia and correspond to the technical specifications for the design of the unit.

A mathematical model of film condensation is constructed which is obtained based on the equations for the conservation of mass, momentum, and energy for a heat-transfer fluid in the limited region of the condensate film and gas phase flowing down the surface of the wall of a heat exchanger in a two-dimensional setting. Equations for conserving the momentum of this model take into account the change in the physical properties of the heat-transfer fluid and condensate film depending on temperature. The boundary conditions of coupling are written for the regions on the inner wall of the flow range of the heat-transfer fluid and outer wall along which the condensate film flows, as well as at the film–gas interface. The boundary problem is solved by approximate and numerical methods, together with the condition for determining the unknown thickness of the film for different settings of the thermodynamic problem. Computational and physical experiments are conducted to study the main parameters and regularities of the process.

Current paper represents the results of the study on extraction of hydrocarbons from oil emulsions using liquid and supercritical extraction processes. High-viscosity oil from Ashalchinskoye accumulation has been taken as a base for the emulsions with subsequent addition of water (0.5-30% wt.). A mixture of propane and butane has been applied as an extractant. The investigations have been carried out at temperatures 85-140 degrees C and pressures 10-15 MPa. The achieved output of light hydrocarbons is 93% of the total mass of hydrocarbons in emulsion. In parallel with the extraction, deasphaltizing has also been carried out.

An original simplified mathematical model of the process of tert-butyl alcohol dehydration in a catalytic zone of the reactive distillation unit with the downward concurrent flow of liquid and vapor phases is developed. The system of heat and mass balance equations includes relationships that allow determining changes in temperature as well as gas and liquid compositions caused by a chemical reaction along the catalyst bed height. Results of calculation of the temperature profile along the catalyst bed height, carried out using the developed model, are in good agreement with data from our previous laboratory studies as well as with data obtained during trial operation of an industrial reactor. (C) 2019 Elsevier Ltd. All rights reserved.