Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265365
V. Radovenchyk, Kateryna Hordiienko, Yaroslav Radovenchyk, T. Krysenko
Today, softening of water in offices and private homes is mainly carried out by the ion exchange method, despite its significant negative impact on the hydrosphere. The development of alternative safe technologies in this field is extremely relevant today. Such an alternative can be considered the use of effective reagents that transfer hardness ions into the solid phase. The use of phosphates as such reagents allows, depending on the conditions, to reduce the residual hardness of water to the level of 0.1 mg-eq/dm3 or less. An important problem of this technology is the efficiency of separating the solid phase from the mother liquor. This step can be implemented by advocating or filtering. Using model calcium solutions treated with appropriate doses of sodium phosphate and flocculants, the most effective of them in settling processes were selected. As flocculants, polyacrylamide was used - as a nonionic flocculant, Magnofloc - 336 from Ciba - as an anionic flocculant, Zetag - 7692 from Ciba - as a cationic flocculant. The flocculant Magnofloc - 336 turned out to be the most effective in settling highly dispersed particles of calcium phosphate. At a flocculant concentration of 30 mg/dm3 for 10 min of settling, the apparent volume of the solid phase decreases to 30 % of the initial volume of the suspension and stabilizes at this value. Other types of flocculants and other doses were less effective. A somewhat different situation is observed when separating the solid phase by filtration. The greatest influence on the filtration rate is caused by the temperature, the hydrogen index and the ratio between the components. Only temperatures below 20 °C significantly affect the rate of filtration. This is especially noticeable at a temperature of 5 °C. At this temperature, the volume of filtrate is 8-20 minutes behind the volume of filtrate of distilled water. At 15 °C, this difference is smaller, and at temperatures above 20 °C, the curves generally overlap. In the pH range of 5-9, there is no significant effect on the filtration rate. Only in a strongly alkaline environment do the necessary filtering times increase significantly, which, in our opinion, is due to the formation of a significant number of amorphous particles of various composition, which can block the pores of the filters. With the stoichiometric ratio of the components, the curve of the change in the filtration rate practically coincides with the curve of the change in the filtration rate of distilled water under the same conditions. When the ratio changes both downward and upward, the conditions for filtering the suspension deteriorate. And the more the ratio differs from stoichiometry, the more developed the structure of the solid phase is and the worse its separation from the liquid phase is. As the ratio between the components changes, so does the pH of the zero charge of the solid particles. If the stoichiometric ratio of the components is at pH 8.15, then when the ratio decrease
{"title":"Use of surfactants for efficient removal of calcium phosphate particles from water","authors":"V. Radovenchyk, Kateryna Hordiienko, Yaroslav Radovenchyk, T. Krysenko","doi":"10.20535/2617-9741.3.2022.265365","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265365","url":null,"abstract":"Today, softening of water in offices and private homes is mainly carried out by the ion exchange method, despite its significant negative impact on the hydrosphere. The development of alternative safe technologies in this field is extremely relevant today. Such an alternative can be considered the use of effective reagents that transfer hardness ions into the solid phase. \u0000The use of phosphates as such reagents allows, depending on the conditions, to reduce the residual hardness of water to the level of 0.1 mg-eq/dm3 or less. An important problem of this technology is the efficiency of separating the solid phase from the mother liquor. This step can be implemented by advocating or filtering. Using model calcium solutions treated with appropriate doses of sodium phosphate and flocculants, the most effective of them in settling processes were selected. As flocculants, polyacrylamide was used - as a nonionic flocculant, Magnofloc - 336 from Ciba - as an anionic flocculant, Zetag - 7692 from Ciba - as a cationic flocculant. \u0000The flocculant Magnofloc - 336 turned out to be the most effective in settling highly dispersed particles of calcium phosphate. At a flocculant concentration of 30 mg/dm3 for 10 min of settling, the apparent volume of the solid phase decreases to 30 % of the initial volume of the suspension and stabilizes at this value. Other types of flocculants and other doses were less effective. \u0000A somewhat different situation is observed when separating the solid phase by filtration. The greatest influence on the filtration rate is caused by the temperature, the hydrogen index and the ratio between the components. Only temperatures below 20 °C significantly affect the rate of filtration. This is especially noticeable at a temperature of 5 °C. At this temperature, the volume of filtrate is 8-20 minutes behind the volume of filtrate of distilled water. At 15 °C, this difference is smaller, and at temperatures above 20 °C, the curves generally overlap. In the pH range of 5-9, there is no significant effect on the filtration rate. Only in a strongly alkaline environment do the necessary filtering times increase significantly, which, in our opinion, is due to the formation of a significant number of amorphous particles of various composition, which can block the pores of the filters. With the stoichiometric ratio of the components, the curve of the change in the filtration rate practically coincides with the curve of the change in the filtration rate of distilled water under the same conditions. When the ratio changes both downward and upward, the conditions for filtering the suspension deteriorate. And the more the ratio differs from stoichiometry, the more developed the structure of the solid phase is and the worse its separation from the liquid phase is. As the ratio between the components changes, so does the pH of the zero charge of the solid particles. If the stoichiometric ratio of the components is at pH 8.15, then when the ratio decrease","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91531996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265360
Vitaliy R. Trishch, Y. Beznosyk, G. Yablonsky, D. Constales
Increasing the intensity of a complex catalytic reaction is an obvious task of chemical technology, and one of the important problems is obtaining the over-equilibrium kinetic characteristics (rate, concentration, yield, selectivity) in the transient non-steady-state regime. As known, for a closed system or an open system of infinite length, the chemical equilibrium is the final state of the chemical reaction, simple or complex. The fundamental properties of the equilibrium composition are its uniqueness and stability. For the closed chemical system, it means that at fixed amounts of chemical elements and at the given temperature, the system reaches the same chemical composition starting from any initial state, and the equilibrium chemical composition is unique and stable. The calculation of the equilibrium composition has become the basis for solving many problems of chemical and biochemical engineering. Such calculations are made based on a list of reactions with known equilibrium constants, or using a list of components with known chemical potentials and minimizing the Gibbs energy of chemical system. In this phenomenon, some initial concentrations of components are replaced by corresponding equilibrium concentrations. The temperature of the system and the total amount of any given chemical element in the system are assumed to be constant. In this paper, the phenomenon of conservatively perturbed-equilibrium (CPE) in multi-route complex catalytic reactions was studied. The computational phenomenon of the CPE is carried out as follows: The values of equilibrium concentrations of all components are determined. Some components are selected so that their initial concentrations differ from the equilibrium concentrations. At least one component is selected so that its initial concentration is equal to the equilibrium value. Perturbations referred above (see item 2) shall comply with all conservation laws of chemical elements which are applicable to this reaction system. The evolution of all concentrations is observed when they tend to the final chemical equilibrium. The following multi-route catalytic mechanisms have been studied: the two-route mechanism with the single common intermediate; the multi-route mechanisms with common steps. The kinetic model of plug-flow reactor (PFR) was chosen. The phenomenon of CPE was demonstrated for all indicated mechanisms. At given rate constants, the mechanism with a single common intermediate exhibited a CPE‑effect which is more pronounced than for the mechanism with common steps. In comparing the kinetic characteristics of non-catalytic and catalytic reactions, a special computer experiment shows that the absolute values of extreme concentrations at the CPE-point are almost the same. It was assumed that non-catalytic and catalytic reaction have the same the overall reaction with same equilibrium constants. This fact makes it possible to estimate the CPE value of the concentrations of com
{"title":"Conservatively perturbed equilibrium phenomenon in multi-route catalytic systems","authors":"Vitaliy R. Trishch, Y. Beznosyk, G. Yablonsky, D. Constales","doi":"10.20535/2617-9741.3.2022.265360","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265360","url":null,"abstract":"Increasing the intensity of a complex catalytic reaction is an obvious task of chemical technology, and one of the important problems is obtaining the over-equilibrium kinetic characteristics (rate, concentration, yield, selectivity) in the transient non-steady-state regime. \u0000As known, for a closed system or an open system of infinite length, the chemical equilibrium is the final state of the chemical reaction, simple or complex. \u0000The fundamental properties of the equilibrium composition are its uniqueness and stability. For the closed chemical system, it means that at fixed amounts of chemical elements and at the given temperature, the system reaches the same chemical composition starting from any initial state, and the equilibrium chemical composition is unique and stable. \u0000The calculation of the equilibrium composition has become the basis for solving many problems of chemical and biochemical engineering. Such calculations are made based on a list of reactions with known equilibrium constants, or using a list of components with known chemical potentials and minimizing the Gibbs energy of chemical system. In this phenomenon, some initial concentrations of components are replaced by corresponding equilibrium concentrations. The temperature of the system and the total amount of any given chemical element in the system are assumed to be constant. \u0000In this paper, the phenomenon of conservatively perturbed-equilibrium (CPE) in multi-route complex catalytic reactions was studied. \u0000The computational phenomenon of the CPE is carried out as follows: \u0000 \u0000The values of equilibrium concentrations of all components are determined. \u0000Some components are selected so that their initial concentrations differ from the equilibrium concentrations. \u0000At least one component is selected so that its initial concentration is equal to the equilibrium value. \u0000Perturbations referred above (see item 2) shall comply with all conservation laws of chemical elements which are applicable to this reaction system. \u0000The evolution of all concentrations is observed when they tend to the final chemical equilibrium. \u0000 \u0000The following multi-route catalytic mechanisms have been studied: \u0000 \u0000the two-route mechanism with the single common intermediate; \u0000the multi-route mechanisms with common steps. \u0000 \u0000The kinetic model of plug-flow reactor (PFR) was chosen. The phenomenon of CPE was demonstrated for all indicated mechanisms. At given rate constants, the mechanism with a single common intermediate exhibited a CPE‑effect which is more pronounced than for the mechanism with common steps. In comparing the kinetic characteristics of non-catalytic and catalytic reactions, a special computer experiment shows that the absolute values of extreme concentrations at the CPE-point are almost the same. It was assumed that non-catalytic and catalytic reaction have the same the overall reaction with same equilibrium constants. \u0000This fact makes it possible to estimate the CPE value of the concentrations of com","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82378068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265361
Liudmyla Yaroshchuk, Yevheniia Tiurina
The development of the production sphere and transport determines the need for industrial and transport oils and greases regeneration. A feature of production processes for purification waste is the significant unstable properties of raw materials that come in for purification. An urgent task is to create control systems for the purification of these substances when they arrive with significantly different properties. The purpose of the study is to improve efficiency of automation systems of adsorption purification by determining relationship between properties of each new batch of raw materials and necessary conditions for its purification. Analysis of the adsorption purification technology, typical solutions of control systems and raw materials properties made it possible to justify the need to create a special mathematical support for control of the changing raw materials stage. A control method aimed at achieving this goal is proposed, which is based on the use of a database. The method involves following stages: searching in the database of substances-analogs for new raw materials; statistical studies of the regime parameters array found for analogues; making decisions on correcting tasks for controllers; parameters adaptation specifically to new raw materials; entering facts about properties of new raw materials and relevant parameters into the database. Statistical studies involve the description of substances properties and the purification process in several forms (types of models) and a gradual change of forms depending on the database capacity. The article provides an example of the algorithm implementation using MS Access. The results are obtained on the basis of methods of system analysis, statistical studies, control systems design and databases. The scientific novelty of obtained results is as follows: in singling out the arrival of new raw materials as a separate operation mode of the control object; in the method of forming tasks for controllers using database of analogue raw materials; in the application of various forms of connection between the properties of substances and mode parameters depending on the database capacity. The obtained results make it possible to increase efficiency of the control systems of waste regeneration productions by reducing time and increasing the accuracy of determining necessary conditions for the processing of various contaminated raw materials.
{"title":"Modeling and control of oils and greases adsorptive purification in the changing raw materials mode","authors":"Liudmyla Yaroshchuk, Yevheniia Tiurina","doi":"10.20535/2617-9741.3.2022.265361","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265361","url":null,"abstract":"The development of the production sphere and transport determines the need for industrial and transport oils and greases regeneration. A feature of production processes for purification waste is the significant unstable properties of raw materials that come in for purification. \u0000An urgent task is to create control systems for the purification of these substances when they arrive with significantly different properties. \u0000The purpose of the study is to improve efficiency of automation systems of adsorption purification by determining relationship between properties of each new batch of raw materials and necessary conditions for its purification. \u0000Analysis of the adsorption purification technology, typical solutions of control systems and raw materials properties made it possible to justify the need to create a special mathematical support for control of the changing raw materials stage. \u0000A control method aimed at achieving this goal is proposed, which is based on the use of a database. The method involves following stages: searching in the database of substances-analogs for new raw materials; statistical studies of the regime parameters array found for analogues; making decisions on correcting tasks for controllers; parameters adaptation specifically to new raw materials; entering facts about properties of new raw materials and relevant parameters into the database. \u0000Statistical studies involve the description of substances properties and the purification process in several forms (types of models) and a gradual change of forms depending on the database capacity. The article provides an example of the algorithm implementation using MS Access. \u0000The results are obtained on the basis of methods of system analysis, statistical studies, control systems design and databases. \u0000The scientific novelty of obtained results is as follows: in singling out the arrival of new raw materials as a separate operation mode of the control object; in the method of forming tasks for controllers using database of analogue raw materials; in the application of various forms of connection between the properties of substances and mode parameters depending on the database capacity. \u0000The obtained results make it possible to increase efficiency of the control systems of waste regeneration productions by reducing time and increasing the accuracy of determining necessary conditions for the processing of various contaminated raw materials.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84937947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265362
V. Halysh, I. Deykun, I. Trus, V. Radovenchyk, M. Gomelya
The transition to non-traditional types of plant raw materials for the production of cellulose and materials based on it is becoming more and more relevant for for scientists and industry around the world. The most expedient for this is the use of waste from the agro-industrial complex in the form of straw or stalks. During the delignification of non-wood lignocellulosic raw materials by the organosolv method, which is quite environmentally friendly, spent solutions with a high soluble lignin content are formed. From an ecological point of view, it is important to create a complex, practically waste-free technology for processing lignin into target products. The paper investigated the possibility of using lignin precipitated from the spent cooking solution after organosolv delignification of rapeseed straw with the following carbonization for obtaining sorbents for the removal of dangerous synthetics dyes from water solution. At the end of cooking, the cellulosic product was separated from the spent solution by filtration. The spent solution was collected in a separate container and treated with 5 volumes of water, resulting in lignin condensation. Condensed lignin was separated from the cooking solution by centrifugation at 5500 rpm for 10 min and washed with distilled water, dehydrated by centrifugation and dried at a temperature of 80 oC until a constant moisture content of 7-8% was reached. Then lignin was treated with a 20 wt.% solution of orthophosphoric acid or 20 wt.% solution of sodium hydroxide, after which it was carbonized in a muffle furnace. Carbonization of lignin leads to a decrease in the average pore size to 2.191-4.421 nm and to an increase in the pore volume by 1.8 times when treated with sodium hydroxide and 2.0 times when treated with orthophosphoric acid, which allows to increase the sorption capacity of the material. The influence of the pH of an aqueous solution on the process of pollutant sorption is decisive. Oxygen-containing functional groups give the surface of sorption materials a positive charge in an acidic environment, which leads to the formation of electrostatic repulsion forces with the dye cation, which also has a positive charge. When the pH is increased to slightly alkaline, dissociation of functional groups occurs, therefore the surface of the sorbent acquires a negative charge, which leads to the emergence of forces of electrostatic attraction with the dye. Absorption of cationic dye increases with increasing pH from 2.0 to 6.0, further increase in pH does not affect the efficiency of the process. Carbonization of lignin leads to an increase in the porosity of the sorbent, so it takes more time to reach full sorption equilibrium. During the first 80 minutes, the maximum absorption rate of methylene blue is observed, after 180 minutes of contact, full sorption equilibrium is reached. Using the Langmuir equation, the sorption isotherm of dye absorption on the obtained sorbents was estimated, and it wa
{"title":"Carbon sorbents from peracetic lignin","authors":"V. Halysh, I. Deykun, I. Trus, V. Radovenchyk, M. Gomelya","doi":"10.20535/2617-9741.3.2022.265362","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265362","url":null,"abstract":"The transition to non-traditional types of plant raw materials for the production of cellulose and materials based on it is becoming more and more relevant for for scientists and industry around the world. The most expedient for this is the use of waste from the agro-industrial complex in the form of straw or stalks. During the delignification of non-wood lignocellulosic raw materials by the organosolv method, which is quite environmentally friendly, spent solutions with a high soluble lignin content are formed. From an ecological point of view, it is important to create a complex, practically waste-free technology for processing lignin into target products. The paper investigated the possibility of using lignin precipitated from the spent cooking solution after organosolv delignification of rapeseed straw with the following carbonization for obtaining sorbents for the removal of dangerous synthetics dyes from water solution. \u0000At the end of cooking, the cellulosic product was separated from the spent solution by filtration. The spent solution was collected in a separate container and treated with 5 volumes of water, resulting in lignin condensation. Condensed lignin was separated from the cooking solution by centrifugation at 5500 rpm for 10 min and washed with distilled water, dehydrated by centrifugation and dried at a temperature of 80 oC until a constant moisture content of 7-8% was reached. \u0000Then lignin was treated with a 20 wt.% solution of orthophosphoric acid or 20 wt.% solution of sodium hydroxide, after which it was carbonized in a muffle furnace. \u0000Carbonization of lignin leads to a decrease in the average pore size to 2.191-4.421 nm and to an increase in the pore volume by 1.8 times when treated with sodium hydroxide and 2.0 times when treated with orthophosphoric acid, which allows to increase the sorption capacity of the material. \u0000The influence of the pH of an aqueous solution on the process of pollutant sorption is decisive. Oxygen-containing functional groups give the surface of sorption materials a positive charge in an acidic environment, which leads to the formation of electrostatic repulsion forces with the dye cation, which also has a positive charge. When the pH is increased to slightly alkaline, dissociation of functional groups occurs, therefore the surface of the sorbent acquires a negative charge, which leads to the emergence of forces of electrostatic attraction with the dye. Absorption of cationic dye increases with increasing pH from 2.0 to 6.0, further increase in pH does not affect the efficiency of the process. \u0000Carbonization of lignin leads to an increase in the porosity of the sorbent, so it takes more time to reach full sorption equilibrium. During the first 80 minutes, the maximum absorption rate of methylene blue is observed, after 180 minutes of contact, full sorption equilibrium is reached. \u0000Using the Langmuir equation, the sorption isotherm of dye absorption on the obtained sorbents was estimated, and it wa","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78422129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265363
Yurii Kholodko, A. Bondarieva, V. Tobilko
Obtaining adsorbent materials based on cheap and available raw materials for water purification from toxic cadmium ions is an important environmental task. It is economically feasible and promising to use natural clays and silicates modified with iron-containing compounds, for example, zero-valent iron. Adsorbents based on kaolin, volcanic glass (perlite), and nanoscale zero-valent iron (Fe0) were studied using the methods of scanning electron microscopy, IR-spectroscopy, X-ray phase analysis, and the method of low-temperature nitrogen adsorption-desorption. Adsorption experiments were performed to evaluate the efficiency of Cd2+ removal from water. The equilibrium metal concentration was determined by inductively coupled plasma atomic emission spectroscopy. The successful completion of modifying the surface of kaolin and perlite with nanoscale zero-valent iron is confirmed by the obtained IR-spectra of the samples, which show characteristic bands at 447 and 682 cm-1, which correspond to Fe-O valence vibrations. On morphology photos of the pure perlite show many artificially formed open and closed pores of different diameters. A typical layered structure is observed for kaolin. After modification of silicates with zero-valent Fe0, clusters of nanosized iron particles appear in the images. The diffractograms of the modified adsorbents show the formation of a crystalline phase of zero-valent iron (α-Fe0), its oxides (FeO), and oxyhydroxides (FeOOH). After applying a layer of iron-containing compounds, the specific surface of the obtained samples increases by 20 - 25%. For modified kaolin and perlite, it reaches values of 12 cm2/g and 10 cm2/g, respectively. At the same time, the total volume of pores increases by 1.5-3 times, but their radius decreases. Thus, the pore radius of the modified kaolin is 2.36 nm, and that of the pure one is 4.3 nm. Coincident, for the modified samples of perlite, there is an insignificant decrease in the size of the pores compared to the unmodified sample - 2.05 nm and 2.36 nm, respectively. This is because, in the modification process, a porous reaction layer of nanosized iron is formed on the surface of silicates, which by its properties differs from the inorganic matrix. The main physicochemical features of removing cadmium ions from water were determined to determine the effectiveness of the obtained adsorbents. During research of the optimal conditions were studied the influence of the concentration of adsorbents, the pH of the aqueous medium, the kinetics of the cadmium removal process and the construct of adsorption isotherms. Under the given research conditions, the optimal dose of adsorbents for the maximum removal of cadmium ions from water is 2 g/l. The study of the dependence of the contact time of modified materials and model solutions on the efficiency of cadmium removal showed that its removal from water occurs relatively quickly. In 20 minutes of interaction, the samples adsorbed about 96% of Cd2+.
{"title":"Synthesis of adsorption materials based on volcanic glass and kaolin","authors":"Yurii Kholodko, A. Bondarieva, V. Tobilko","doi":"10.20535/2617-9741.3.2022.265363","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265363","url":null,"abstract":"Obtaining adsorbent materials based on cheap and available raw materials for water purification from toxic cadmium ions is an important environmental task. It is economically feasible and promising to use natural clays and silicates modified with iron-containing compounds, for example, zero-valent iron. \u0000Adsorbents based on kaolin, volcanic glass (perlite), and nanoscale zero-valent iron (Fe0) were studied using the methods of scanning electron microscopy, IR-spectroscopy, X-ray phase analysis, and the method of low-temperature nitrogen adsorption-desorption. Adsorption experiments were performed to evaluate the efficiency of Cd2+ removal from water. The equilibrium metal concentration was determined by inductively coupled plasma atomic emission spectroscopy. The successful completion of modifying the surface of kaolin and perlite with nanoscale zero-valent iron is confirmed by the obtained IR-spectra of the samples, which show characteristic bands at 447 and 682 cm-1, which correspond to Fe-O valence vibrations. On morphology photos of the pure perlite show many artificially formed open and closed pores of different diameters. A typical layered structure is observed for kaolin. After modification of silicates with zero-valent Fe0, clusters of nanosized iron particles appear in the images. The diffractograms of the modified adsorbents show the formation of a crystalline phase of zero-valent iron (α-Fe0), its oxides (FeO), and oxyhydroxides (FeOOH). After applying a layer of iron-containing compounds, the specific surface of the obtained samples increases by 20 - 25%. For modified kaolin and perlite, it reaches values of 12 cm2/g and 10 cm2/g, respectively. At the same time, the total volume of pores increases by 1.5-3 times, but their radius decreases. Thus, the pore radius of the modified kaolin is 2.36 nm, and that of the pure one is 4.3 nm. Coincident, for the modified samples of perlite, there is an insignificant decrease in the size of the pores compared to the unmodified sample - 2.05 nm and 2.36 nm, respectively. This is because, in the modification process, a porous reaction layer of nanosized iron is formed on the surface of silicates, which by its properties differs from the inorganic matrix. The main physicochemical features of removing cadmium ions from water were determined to determine the effectiveness of the obtained adsorbents. During research of the optimal conditions were studied the influence of the concentration of adsorbents, the pH of the aqueous medium, the kinetics of the cadmium removal process and the construct of adsorption isotherms. Under the given research conditions, the optimal dose of adsorbents for the maximum removal of cadmium ions from water is 2 g/l. The study of the dependence of the contact time of modified materials and model solutions on the efficiency of cadmium removal showed that its removal from water occurs relatively quickly. In 20 minutes of interaction, the samples adsorbed about 96% of Cd2+. ","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90479077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265359
Іgor Mikulionok, Аnton Karvatskii, O. Ivanenko, S. Leleka
A classification of heat exchangers with fluidization of bulk material for use in enterprises of the chemical, mining, construction, food, metallurgical and processing industries has been developed. A critical review of the most characteristic designs of heat exchangers with a fluidized bed, proposed by scientists, designers and inventors of the leading countries of the world, has been carried out. The designs of heat exchangers are analyzed depending on the method of fluidization, the role of bulk material in the heat exchange process, the nature of the heat exchange process over time, the nature of fluidization (in continuous heat exchangers), the mechanism of heat exchange of bulk material, the number of fluidized beds, the presence of additional heat exchange devices in the heat exchanger, the presence of movable structural elements, as well as the type of bulk material of the fluidized bed. An analysis of the designs of heat exchangers with a fluidized bed indicates their considerable diversity, however, the most simple to manufacture and operate reliable devices with fixed structural elements and one fluidized bed remain in demand by the industry. The most promising direction for improving fluidized bed heat exchangers is the development of specialized (for processing bulk material or fluid coolant) designs of apparatuses. In the future, it is planned to analyze the designs of other types of heat exchangers, as well as ways to improve their efficiency.
{"title":"Heat exchangers with fluidization of bulk material (Design review)","authors":"Іgor Mikulionok, Аnton Karvatskii, O. Ivanenko, S. Leleka","doi":"10.20535/2617-9741.3.2022.265359","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265359","url":null,"abstract":"A classification of heat exchangers with fluidization of bulk material for use in enterprises of the chemical, mining, construction, food, metallurgical and processing industries has been developed. A critical review of the most characteristic designs of heat exchangers with a fluidized bed, proposed by scientists, designers and inventors of the leading countries of the world, has been carried out. The designs of heat exchangers are analyzed depending on the method of fluidization, the role of bulk material in the heat exchange process, the nature of the heat exchange process over time, the nature of fluidization (in continuous heat exchangers), the mechanism of heat exchange of bulk material, the number of fluidized beds, the presence of additional heat exchange devices in the heat exchanger, the presence of movable structural elements, as well as the type of bulk material of the fluidized bed. \u0000An analysis of the designs of heat exchangers with a fluidized bed indicates their considerable diversity, however, the most simple to manufacture and operate reliable devices with fixed structural elements and one fluidized bed remain in demand by the industry. The most promising direction for improving fluidized bed heat exchangers is the development of specialized (for processing bulk material or fluid coolant) designs of apparatuses. \u0000In the future, it is planned to analyze the designs of other types of heat exchangers, as well as ways to improve their efficiency.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73198223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.20535/2617-9741.3.2022.265358
Yaroslav M. Kornienko, S. Haidai, Pavlo Yevziutin, Oleksandr Sameliuk
An increase in the intensity of diffusion-controlled processes during granulation is provided by apparatuses with non-homogeneous fluidization, the hydrodynamics of which significantly depends on the structural features of the granulator chamber and the gas distributing device (GDD). The main problem is the formation of stagnant zones on the working surface of GDD, which, when supplying a coolant with temperature that exceeds the melting point of granules, leads to the melting of solids and the termination of the process. In this work, the simulation of hydrodynamics in the granulator chamber was carried out using SolidWorks 2022 SP2 for 4 types of gas distribution devices (GDD) of different configurations with different values of the cross-section coefficient of GDD. The analysis of the simulation results shows that the most significant influence on the hydrodynamic activity index near the surface of GDD iha has the cross-section coefficient of GDD φ, since even an insignificant increase in the value of φ from 3.0 to 3.5% leads to a significant decrease in the hydrodynamic activity index iha by at least 1.4 times for all considered types of GDD. The simulation of hydrodynamics was carried out without taking into account the presence of solid granular material in the granulator chamber and near the surface of GDD plate.
{"title":"Simulation of hydrodynamics in gas distribution devices for non-homogeneous mode of fluidization","authors":"Yaroslav M. Kornienko, S. Haidai, Pavlo Yevziutin, Oleksandr Sameliuk","doi":"10.20535/2617-9741.3.2022.265358","DOIUrl":"https://doi.org/10.20535/2617-9741.3.2022.265358","url":null,"abstract":"An increase in the intensity of diffusion-controlled processes during granulation is provided by apparatuses with non-homogeneous fluidization, the hydrodynamics of which significantly depends on the structural features of the granulator chamber and the gas distributing device (GDD). The main problem is the formation of stagnant zones on the working surface of GDD, which, when supplying a coolant with temperature that exceeds the melting point of granules, leads to the melting of solids and the termination of the process. \u0000In this work, the simulation of hydrodynamics in the granulator chamber was carried out using SolidWorks 2022 SP2 for 4 types of gas distribution devices (GDD) of different configurations with different values of the cross-section coefficient of GDD. \u0000The analysis of the simulation results shows that the most significant influence on the hydrodynamic activity index near the surface of GDD iha has the cross-section coefficient of GDD φ, since even an insignificant increase in the value of φ from 3.0 to 3.5% leads to a significant decrease in the hydrodynamic activity index iha by at least 1.4 times for all considered types of GDD. The simulation of hydrodynamics was carried out without taking into account the presence of solid granular material in the granulator chamber and near the surface of GDD plate.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87019946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.20535/2617-9741.2.2022.260347
L. Zhuchenko
The production of carbon products is largely resource- and energy-intensive. That is why increasing the efficiency of this production is an urgent scientific and practical task, especially in modern conditions of constant growth of energy costs. An effective way to solve this problem is to create a modern process control system, taking into account the possible failures of system elements. The practice of operating hydraulic presses in carbon graphite production, the control valve of the hydraulic press sometimes fails or works with errors. That is why this paper considers the stage of loading the process of forming carbon products in terms of building a fault-tolerant pressing speed control system. The article investigates the fault-tolerant control system of carbon products, which is synthesized on the basis of traditional fault-tolerant systems for non-cyclic processes and control systems with iterative learning, which have demonstrated their effectiveness in control technological processes of cyclical nature. A method using linear matrix inequalities has been developed for optimal adjustment of control system parameters. Based on the combination of control with iterative learning and control that takes into account the failures of regulators, built a control system for the formation of carbon products, which takes into account both the cyclical nature of the technological process and possible failures of regulators. The research of the effectiveness of the control system by comparing its work with traditional fault-tolerant systems and control systems with iterative learning in the event of faults and disturbances of various kinds showed that the proposed system improves control quality not only over time during each cycle, but also from cycle to cycle. Further research should be aimed at the practical application of the proposed control system for different technological processes in different types of failures of regulatory bodies and the action of disturbances of different nature.
{"title":"Research of fault-tolerant control system of the formation process of carbon products","authors":"L. Zhuchenko","doi":"10.20535/2617-9741.2.2022.260347","DOIUrl":"https://doi.org/10.20535/2617-9741.2.2022.260347","url":null,"abstract":"The production of carbon products is largely resource- and energy-intensive. That is why increasing the efficiency of this production is an urgent scientific and practical task, especially in modern conditions of constant growth of energy costs. An effective way to solve this problem is to create a modern process control system, taking into account the possible failures of system elements. \u0000The practice of operating hydraulic presses in carbon graphite production, the control valve of the hydraulic press sometimes fails or works with errors. That is why this paper considers the stage of loading the process of forming carbon products in terms of building a fault-tolerant pressing speed control system. \u0000The article investigates the fault-tolerant control system of carbon products, which is synthesized on the basis of traditional fault-tolerant systems for non-cyclic processes and control systems with iterative learning, which have demonstrated their effectiveness in control technological processes of cyclical nature. A method using linear matrix inequalities has been developed for optimal adjustment of control system parameters. \u0000Based on the combination of control with iterative learning and control that takes into account the failures of regulators, built a control system for the formation of carbon products, which takes into account both the cyclical nature of the technological process and possible failures of regulators. The research of the effectiveness of the control system by comparing its work with traditional fault-tolerant systems and control systems with iterative learning in the event of faults and disturbances of various kinds showed that the proposed system improves control quality not only over time during each cycle, but also from cycle to cycle. \u0000Further research should be aimed at the practical application of the proposed control system for different technological processes in different types of failures of regulatory bodies and the action of disturbances of different nature.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72930846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.20535/2617-9741.2.2022.260342
Valerii Shcherbyna, Denys Shvachko
Rotary kilns are used in many industries to process bulk raw materials. In the building materials industry, rotary kilns are widely used for heat treatment. However, the fuel utilization factor in rotary kilns is extremely low. Thus, the bulk of cement clinker is fired in furnaces, the thermal efficiency of which does not exceed 55-60%. Therefore, the task of increasing the efficiency of such units is extremely relevant. In operating furnaces, heat losses to the environment only through the furnace body reach 20-25% of the total heat of combustion. In this case, one of the main factors determining the thermal efficiency of furnace operation is the value of thermal resistance of lining. The aim of the work is to study the evolution and temperature changes in the rotary kiln lining made of shaped refractory to reduce heat losses to the environment and improve the efficiency by increasing the thermal resistance of the lining. The increase in thermal resistance is achieved by changing the shape of the refractory by creating appropriate cells and introducing additional fibrous insulating material into them. A mathematical model and software have been developed and numerical calculations have been carried out to determine non-stationary temperature fields in the lining with a thermal insulating element and to substantiate the choice of an appropriate thermal insulating fibrous material. Analyzing the calculation results, it is possible to conclude about the expediency of using a lining with increased thermal resistance. The use of this technical solution makes it possible to reduce heat losses through the housing by 18-24%, to increase the amount of transferred material in the working zone by 1.5-8% due to the creation of an appropriate temperature field in the working volume, and to reduce the mass of the lining and the furnace as a whole. and increase the energy efficiency of the thermal unit. The presence of cells with additional thermal insulation contributes to the emergence of thermal pulsations having oscillatory character and affecting the intensification of heat and mass exchange processes, which in general contributes to the performance of the thermal unit. A significant advantage of this method is also the fact that increasing the energy efficiency of the furnace does not require additional fuel consumption, increasing the temperature or increasing the enthalpy of the combustion products.
{"title":"The effect of thermal insulation of the lining on the heat exchange of rotating apparatuses","authors":"Valerii Shcherbyna, Denys Shvachko","doi":"10.20535/2617-9741.2.2022.260342","DOIUrl":"https://doi.org/10.20535/2617-9741.2.2022.260342","url":null,"abstract":"Rotary kilns are used in many industries to process bulk raw materials. In the building materials industry, rotary kilns are widely used for heat treatment. However, the fuel utilization factor in rotary kilns is extremely low. Thus, the bulk of cement clinker is fired in furnaces, the thermal efficiency of which does not exceed 55-60%. Therefore, the task of increasing the efficiency of such units is extremely relevant. In operating furnaces, heat losses to the environment only through the furnace body reach 20-25% of the total heat of combustion. In this case, one of the main factors determining the thermal efficiency of furnace operation is the value of thermal resistance of lining. \u0000The aim of the work is to study the evolution and temperature changes in the rotary kiln lining made of shaped refractory to reduce heat losses to the environment and improve the efficiency by increasing the thermal resistance of the lining. The increase in thermal resistance is achieved by changing the shape of the refractory by creating appropriate cells and introducing additional fibrous insulating material into them. \u0000A mathematical model and software have been developed and numerical calculations have been carried out to determine non-stationary temperature fields in the lining with a thermal insulating element and to substantiate the choice of an appropriate thermal insulating fibrous material. \u0000Analyzing the calculation results, it is possible to conclude about the expediency of using a lining with increased thermal resistance. The use of this technical solution makes it possible to reduce heat losses through the housing by 18-24%, to increase the amount of transferred material in the working zone by 1.5-8% due to the creation of an appropriate temperature field in the working volume, and to reduce the mass of the lining and the furnace as a whole. and increase the energy efficiency of the thermal unit. \u0000The presence of cells with additional thermal insulation contributes to the emergence of thermal pulsations having oscillatory character and affecting the intensification of heat and mass exchange processes, which in general contributes to the performance of the thermal unit. \u0000A significant advantage of this method is also the fact that increasing the energy efficiency of the furnace does not require additional fuel consumption, increasing the temperature or increasing the enthalpy of the combustion products.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81544987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.20535/2617-9741.2.2022.260349
B. Korniyenko, A. Nesteruk
One of the most common methods of making mineral fertilizers is granulation. Fertilizers in the form of granules have a number of advantages over conventional fertilizers in the form of powder or liquid, namely, ease of transportation, well absorbed and less susceptible to weathering from the soil, convenient to use. To obtain solid particles from liquid starting material such as solutions, emulsions or suspensions, the following processes are used: crystallization, granulation, spray drying. Depending on the focus of the study, the fluidized bed granulation process can be modeled at different levels of abstraction. The dynamics of individual particles is modeled on a microscopic scale. The interaction of a particle with a liquid, equipment or other particles is considered. The next rougher level of abstraction is the mesoscale. Here the particles are divided into classes according to their characteristics. It is assumed that the particles of the class have the same properties and dynamics. On a macroscopic scale, the roughest level of approximation, attention is focused on the integral behavior of the whole set of particles. As a result, the selected characteristic values describe the state of the particle layer. There are different approaches to modeling for each scale. It is proposed to describe the microscopic scale using the hydrodynamics model, the mesoscale using the balance model, and the macroscopic scale using the moments method or the Lagrange-Euler model. A combined balance-hydrodynamics model and a multi-chamber balance model that can be used for the tasks of building information technology for fluidized bed granulation process control technology are also considered.
{"title":"Mathematical modelling of granulation process in fluidised bed (overview of models)","authors":"B. Korniyenko, A. Nesteruk","doi":"10.20535/2617-9741.2.2022.260349","DOIUrl":"https://doi.org/10.20535/2617-9741.2.2022.260349","url":null,"abstract":"One of the most common methods of making mineral fertilizers is granulation. Fertilizers in the form of granules have a number of advantages over conventional fertilizers in the form of powder or liquid, namely, ease of transportation, well absorbed and less susceptible to weathering from the soil, convenient to use. To obtain solid particles from liquid starting material such as solutions, emulsions or suspensions, the following processes are used: crystallization, granulation, spray drying. Depending on the focus of the study, the fluidized bed granulation process can be modeled at different levels of abstraction. The dynamics of individual particles is modeled on a microscopic scale. The interaction of a particle with a liquid, equipment or other particles is considered. The next rougher level of abstraction is the mesoscale. Here the particles are divided into classes according to their characteristics. It is assumed that the particles of the class have the same properties and dynamics. On a macroscopic scale, the roughest level of approximation, attention is focused on the integral behavior of the whole set of particles. As a result, the selected characteristic values describe the state of the particle layer. There are different approaches to modeling for each scale. It is proposed to describe the microscopic scale using the hydrodynamics model, the mesoscale using the balance model, and the macroscopic scale using the moments method or the Lagrange-Euler model. A combined balance-hydrodynamics model and a multi-chamber balance model that can be used for the tasks of building information technology for fluidized bed granulation process control technology are also considered.","PeriodicalId":20682,"journal":{"name":"Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87430226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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