A. Andreev, D. S. Pashkevich, D. Bryankin, N. Belov, P. S. Kambur, V. V. Kapustin, S. Zhuravkov
An integrated method is proposed for examining the compositions of fluorine-bearing gaseous mixtures, which allows for determining the concentration of HF, F2, N2, O2, CO2, CF4, and C2F6 in these mixtures. The concentration of hydrogen fluoride is determined by its sorption on sodium fluoride followed by the determination of the fluoride ion by the potentiometric method. The lower threshold of determination of hydrogen fluoride is found to be 0.09 vol.%. The concentrations of N2, O2, CO2, CF4, and C2F6 are determined by the gas chromatographic method using a thermal conductivity detector. The proposed gas-chromatography method offers a quantitative measurement of the concentration of N2, O2, CO2, CF4, and C2F6 at the lower limits of detection of 0.008, 0.012, 0.011, 0.009, and 0.019 vol.%, respectively. Based on the developed method, the compositions of a standard fluorine-nitrogen (10 vol.%) and anodic gas samples, synthesized in a laboratory electrolyzer at the National Research Tomsk Polytechnic University and in an industrial electrochemical reactor at JSC Siberian Chemical Plant (Russia), are studied.
{"title":"A Comprehensive Approach to Investigating Fluorine-Bearing Gas Mixtures","authors":"A. Andreev, D. S. Pashkevich, D. Bryankin, N. Belov, P. S. Kambur, V. V. Kapustin, S. Zhuravkov","doi":"10.18321/ectj1472","DOIUrl":"https://doi.org/10.18321/ectj1472","url":null,"abstract":" An integrated method is proposed for examining the compositions of fluorine-bearing gaseous mixtures, which allows for determining the concentration of HF, F2, N2, O2, CO2, CF4, and C2F6 in these mixtures. The concentration of hydrogen fluoride is determined by its sorption on sodium fluoride followed by the determination of the fluoride ion by the potentiometric method. The lower threshold of determination of hydrogen fluoride is found to be 0.09 vol.%. The concentrations of N2, O2, CO2, CF4, and C2F6 are determined by the gas chromatographic method using a thermal conductivity detector. The proposed gas-chromatography method offers a quantitative measurement of the concentration of N2, O2, CO2, CF4, and C2F6 at the lower limits of detection of 0.008, 0.012, 0.011, 0.009, and 0.019 vol.%, respectively. Based on the developed method, the compositions of a standard fluorine-nitrogen (10 vol.%) and anodic gas samples, synthesized in a laboratory electrolyzer at the National Research Tomsk Polytechnic University and in an industrial electrochemical reactor at JSC Siberian Chemical Plant (Russia), are studied.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44387367","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}
A. Ismailova, G.Zh. Akanova, Kh. S. Tassibekov, D. Kamysbayev, B. Yermagambet, M. Kazankapova, Z. Kassenova
This work obtained a sorbent based on humic acids (HA) isolated from oxidized brown coals of the Maikuben deposit. The study of humic acids by IR spectroscopy showed the presence of various functional groups (OH-, COOH-) in the sorbent, which can enter into ion-exchange reactions with metals. Humic acids have been tested as a sorbent for neodymium. Neodymium sorption was carried out under static conditions from nitrate solutions. It was found that with a sorption time of 30 min and a solution pH is 1.0, the sorption efficiency of neodymium is 95.5%. A sorbent based on humic acids was used to separate neodymium from a solution obtained by dissolving electronic waste (neodymium magnet). SEM-analysis and mapping of the sorbent surface after neodymium sorption showed that neodymium was absent on the sorbent surface.
{"title":"Sorption of Neodymium from Nitrate Solutions by Humic Acids-Based Sorbent","authors":"A. Ismailova, G.Zh. Akanova, Kh. S. Tassibekov, D. Kamysbayev, B. Yermagambet, M. Kazankapova, Z. Kassenova","doi":"10.18321/ectj1475","DOIUrl":"https://doi.org/10.18321/ectj1475","url":null,"abstract":" This work obtained a sorbent based on humic acids (HA) isolated from oxidized brown coals of the Maikuben deposit. The study of humic acids by IR spectroscopy showed the presence of various functional groups (OH-, COOH-) in the sorbent, which can enter into ion-exchange reactions with metals. Humic acids have been tested as a sorbent for neodymium. Neodymium sorption was carried out under static conditions from nitrate solutions. It was found that with a sorption time of 30 min and a solution pH is 1.0, the sorption efficiency of neodymium is 95.5%. A sorbent based on humic acids was used to separate neodymium from a solution obtained by dissolving electronic waste (neodymium magnet). SEM-analysis and mapping of the sorbent surface after neodymium sorption showed that neodymium was absent on the sorbent surface.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42221147","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}
J. Rasulzade, Y. Maksum, M. Nogaibayeva, S. Rustamov, B. Akhmetov
Today’s 3D printers allow the creation of very advanced structures from various materials, starting from simple plastics up to metal alloys. Since the printing time and amount of material used to create structures are considered very important in terms of cost and energy consumption, it is better to optimize structures for that particular application taking into account all the conditions. In the current work, U-Net convolutional neural network-based topology optimization method (TO) that allows to reduce the material usage and eventually reduces the cost of 3D printing is introduced. The results showed that the accuracy of the method is highly reliable and can be used for designing various 3D printable structures and it applies to any type of materials since properties of materials can be included in TO.
{"title":"Reduction of Material Usage in 3D Printable Structures Using Topology Optimization Accelerated with U-Net Convolutional Neural Network","authors":"J. Rasulzade, Y. Maksum, M. Nogaibayeva, S. Rustamov, B. Akhmetov","doi":"10.18321/ectj1471","DOIUrl":"https://doi.org/10.18321/ectj1471","url":null,"abstract":"Today’s 3D printers allow the creation of very advanced structures from various materials, starting from simple plastics up to metal alloys. Since the printing time and amount of material used to create structures are considered very important in terms of cost and energy consumption, it is better to optimize structures for that particular application taking into account all the conditions. In the current work, U-Net convolutional neural network-based topology optimization method (TO) that allows to reduce the material usage and eventually reduces the cost of 3D printing is introduced. The results showed that the accuracy of the method is highly reliable and can be used for designing various 3D printable structures and it applies to any type of materials since properties of materials can be included in TO.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43490139","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}
M. Ivantsov, K. Krysanova, A. A. Grabchak, M. Kulikova
Hydrothermal carbonization of lignin was used to prepare a precursor of a carbon-containing support to obtain supported iron-containing catalysts for the hydrogenation of carbon monoxide. In the paper, the possibility of forming a carbon support prone to the deposition of metal ions was investigated. Deep structural transformations occurring in the polymer matrix of lignin were demonstrated by FTIR spectroscopy. The thermal stability of the support material was determined by thermal analysis in the region up to 400 °C. The formation of magnetite nanoparticles with a size of about 7‒8 nm at the stage of preliminary calcination of the metal-carbon system was shown by X-ray diffraction analysis (XRD). It was found that the resulting systems have high activity comparable to the activity of the system based on activated carbon: the conversion of carbon monoxide reached 98%, the yield of C5+ hydrocarbons reached 72 g/m3.
{"title":"Hydrogenation of CO in the Presence of Fe-Containing Materials Based on Carbon Supports","authors":"M. Ivantsov, K. Krysanova, A. A. Grabchak, M. Kulikova","doi":"10.18321/ectj1474","DOIUrl":"https://doi.org/10.18321/ectj1474","url":null,"abstract":"Hydrothermal carbonization of lignin was used to prepare a precursor of a carbon-containing support to obtain supported iron-containing catalysts for the hydrogenation of carbon monoxide. In the paper, the possibility of forming a carbon support prone to the deposition of metal ions was investigated. Deep structural transformations occurring in the polymer matrix of lignin were demonstrated by FTIR spectroscopy. The thermal stability of the support material was determined by thermal analysis in the region up to 400 °C. The formation of magnetite nanoparticles with a size of about 7‒8 nm at the stage of preliminary calcination of the metal-carbon system was shown by X-ray diffraction analysis (XRD). It was found that the resulting systems have high activity comparable to the activity of the system based on activated carbon: the conversion of carbon monoxide reached 98%, the yield of C5+ hydrocarbons reached 72 g/m3.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43871986","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}
P.A. Baimyrza, R. Iminova, B. Kudaibergenova, G. Kairalapova
Nanocomposite films based on chitosan nanowhisker (CsW) with ionic and nonorganic polymers were prepared and studied on the swelling and mechanical properties. Сhitosan nanowhiskers were made from α-chitin by using a top-down approach. Ionic polymer polyvinyl alcohol (PVA) and nonorganic bentonite clay (BC) were employed to prepare chitosan nanowhisker bionanocomposite film taking into account their biocompatibility and nontoxicity. Fourier transform infrared spectroscopy analysis, swelling degree measurements and mechanical tests were employed to analyze the influence of significant PVA and bentonite amounts on the film properties. The mechanical strength was found to increase with the rise of the PVA concentration. This is an advantage for producing wound dressing material. The increase in BC concentration in the film resulted in high film stability in water and different mediums and in higher water absorbance than that of CsW/PVA film. However, the highest swelling degree was for a film of CsW itself but the mechanical strength was lower and insufficient to use it for the wound dressing material. Thus, the incorporation of PVA and BC into chitosan nanowhisker can enhance the swelling capacity and mechanical strength.
{"title":"Bionanocomposite Films Based on Chitosan with Bentonite Clay and Polyvinyl Alcohol","authors":"P.A. Baimyrza, R. Iminova, B. Kudaibergenova, G. Kairalapova","doi":"10.18321/ectj1470","DOIUrl":"https://doi.org/10.18321/ectj1470","url":null,"abstract":"Nanocomposite films based on chitosan nanowhisker (CsW) with ionic and nonorganic polymers were prepared and studied on the swelling and mechanical properties. Сhitosan nanowhiskers were made from α-chitin by using a top-down approach. Ionic polymer polyvinyl alcohol (PVA) and nonorganic bentonite clay (BC) were employed to prepare chitosan nanowhisker bionanocomposite film taking into account their biocompatibility and nontoxicity. Fourier transform infrared spectroscopy analysis, swelling degree measurements and mechanical tests were employed to analyze the influence of significant PVA and bentonite amounts on the film properties. The mechanical strength was found to increase with the rise of the PVA concentration. This is an advantage for producing wound dressing material. The increase in BC concentration in the film resulted in high film stability in water and different mediums and in higher water absorbance than that of CsW/PVA film. However, the highest swelling degree was for a film of CsW itself but the mechanical strength was lower and insufficient to use it for the wound dressing material. Thus, the incorporation of PVA and BC into chitosan nanowhisker can enhance the swelling capacity and mechanical strength.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48360980","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}
O. Narivs’kyi, R. Atchibayev, A. Kemelzhanova, G. Yar-Mukhamedovа, G. Snizhnoi, S. Subbotin, A. Beisebayeva
Mathematical models that describe the dependences of the critical temperatures of pitting formation of AISI 304, 08Kh18N10, AISI 321, 12Kh18N10T steels in model circulating waters with pH 4…8 and chloride concentrations from 350 to 600 mg/l on their chemical composition and structure have been developed. They are based on linear squares regressions and a feed-forward neural network for reduced feature numbers. Using the developed mathematical models, it was found that the critical pitting temperatures of these steels increase with an increase in the pH of the circulating water, the number of oxides up to 3.95 μm in size, the average distance between titanium nitrides, the Cr content and a decrease in the concentration of chlorides in the circulating waters, the average distance between oxides and average austenite grain diameter. At the same time, it was found that the geometric dimensions of the steel structure most intensively affect their pitting resistance in circulating waters, and the effect of their chemical composition is minimal and is determined by the amount of Cr, which contributes to an increase in the pitting resistance of steels, probably increasing the solubility of nitrogen in the austenite solid solution. It is proposed to use the developed mathematical models to select the optimal heats of these steels for the production of heat exchangers and predict their pitting resistance during their operation in circulating waters.
{"title":"Mathematical Modeling of the Corrosion Behavior of Austenitic Steels in Chloride-Containing Media During the Operation of Plate-Like Heat Exchangers","authors":"O. Narivs’kyi, R. Atchibayev, A. Kemelzhanova, G. Yar-Mukhamedovа, G. Snizhnoi, S. Subbotin, A. Beisebayeva","doi":"10.18321/ectj1473","DOIUrl":"https://doi.org/10.18321/ectj1473","url":null,"abstract":" Mathematical models that describe the dependences of the critical temperatures of pitting formation of AISI 304, 08Kh18N10, AISI 321, 12Kh18N10T steels in model circulating waters with pH 4…8 and chloride concentrations from 350 to 600 mg/l on their chemical composition and structure have been developed. They are based on linear squares regressions and a feed-forward neural network for reduced feature numbers. Using the developed mathematical models, it was found that the critical pitting temperatures of these steels increase with an increase in the pH of the circulating water, the number of oxides up to 3.95 μm in size, the average distance between titanium nitrides, the Cr content and a decrease in the concentration of chlorides in the circulating waters, the average distance between oxides and average austenite grain diameter. At the same time, it was found that the geometric dimensions of the steel structure most intensively affect their pitting resistance in circulating waters, and the effect of their chemical composition is minimal and is determined by the amount of Cr, which contributes to an increase in the pitting resistance of steels, probably increasing the solubility of nitrogen in the austenite solid solution. It is proposed to use the developed mathematical models to select the optimal heats of these steels for the production of heat exchangers and predict their pitting resistance during their operation in circulating waters.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45417813","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}
A. Andreev, N. Belov, V. Makarova, G. Shandryuk, D. Bryankin, D. S. Pashkevich, A. Alentiev
This work aims to obtain the dispersions based on polyethylene glycols (PEGs) of various molecular masses (MM) and perfluorodecalin (PFD) for subsequent direct fluorination. The solubility of the components was estimated using laser interferometry and differential scanning calorimetry, and it was shown that PEGs with different MM are not highly compatible with PFD. The dispersions were prepared during sonication. Gel permeation chromatography (GPC) analysis indicated that MMs almost did not change in this process. While the sonication of PEG-PFD, there is a formation of dispersion with the particle sizes distribution in a range of 0.4‒2 μm depending on the MM of PEG. The dispersion is metastable for several hours, even though its stability was significantly affected by additional bubbling with the gas flow. Moreover, the dispersions with a solid PEG phase (MM > 600 Da) were subjected to a smaller change compared to a liquid one (MM < 600 Da). The results of this research shed light on the applicability of the ultrasonic preparation of PEGs in PFD for liquid-phase fluorination with obtaining perfluorinated polyether of target MM.
{"title":"Dispersion of Polyethylene Glycol in Perfluorodecalin for Liquid Phase Fluorination","authors":"A. Andreev, N. Belov, V. Makarova, G. Shandryuk, D. Bryankin, D. S. Pashkevich, A. Alentiev","doi":"10.18321/ectj1439","DOIUrl":"https://doi.org/10.18321/ectj1439","url":null,"abstract":"This work aims to obtain the dispersions based on polyethylene glycols (PEGs) of various molecular masses (MM) and perfluorodecalin (PFD) for subsequent direct fluorination. The solubility of the components was estimated using laser interferometry and differential scanning calorimetry, and it was shown that PEGs with different MM are not highly compatible with PFD. The dispersions were prepared during sonication. Gel permeation chromatography (GPC) analysis indicated that MMs almost did not change in this process. While the sonication of PEG-PFD, there is a formation of dispersion with the particle sizes distribution in a range of 0.4‒2 μm depending on the MM of PEG. The dispersion is metastable for several hours, even though its stability was significantly affected by additional bubbling with the gas flow. Moreover, the dispersions with a solid PEG phase (MM > 600 Da) were subjected to a smaller change compared to a liquid one (MM < 600 Da). The results of this research shed light on the applicability of the ultrasonic preparation of PEGs in PFD for liquid-phase fluorination with obtaining perfluorinated polyether of target MM.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44219452","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}
B. Davletiyarov, K. Akmurzina, A. Seralin, G. Bizhanova, B. Baptayev, M. Balanay, A. Ng
The CsPbI2Br perovskite quantum dots (PQDs) have great potential in photovoltaic applications due to their phase stability and optoelectronic properties. In this work, the synthesis technique of CsPbI2Br PQDs with the investigation of their properties and applications are identified. The critical issues and precautions for preparing PQDs are also discussed. It is also interesting to find that the collected supernatant solutions during the purification of PQDs can be recycled for preparing other types of PQDs. Meanwhile, this work demonstrates different approaches (i) thermal annealing, usage of (ii) methyl acetate and (iii) ethyl acetate as anti-solvents for preparing CsPbI2Br PQDs in the form of thin films on glass substrates. The obtained samples are characterized in terms of morphology, structural and optical properties. The results of this work can provide useful information for researchers, particularly for those who are starting to synthesize PQDs for fabrications of solid-state devices.
{"title":"Investigation of Synthesis and Deposition Methods for Cesium-Based Perovskite Quantum Dots for Solar Cell Applications","authors":"B. Davletiyarov, K. Akmurzina, A. Seralin, G. Bizhanova, B. Baptayev, M. Balanay, A. Ng","doi":"10.18321/ectj1437","DOIUrl":"https://doi.org/10.18321/ectj1437","url":null,"abstract":"The CsPbI2Br perovskite quantum dots (PQDs) have great potential in photovoltaic applications due to their phase stability and optoelectronic properties. In this work, the synthesis technique of CsPbI2Br PQDs with the investigation of their properties and applications are identified. The critical issues and precautions for preparing PQDs are also discussed. It is also interesting to find that the collected supernatant solutions during the purification of PQDs can be recycled for preparing other types of PQDs. Meanwhile, this work demonstrates different approaches (i) thermal annealing, usage of (ii) methyl acetate and (iii) ethyl acetate as anti-solvents for preparing CsPbI2Br PQDs in the form of thin films on glass substrates. The obtained samples are characterized in terms of morphology, structural and optical properties. The results of this work can provide useful information for researchers, particularly for those who are starting to synthesize PQDs for fabrications of solid-state devices.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42006947","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}
N. Ashurov, B. Oksengendler, S. Maksimov, A. Zakhidov, G. Yar-Mukhamedova, G. Zhamanbayeva
The fundamental aspects of the perovskite absorber formation of solar irradiation for two generally accepted one- and two-step technologies are considered. For the on-step variant, two stages of perovskite formation, called “through solution” and “intermediate colloid compounds of precursors”, were identified. The successive deposition of precursors is described in terms of thermodynamics and the Ostwald ripening model. The optimal conditions for the concentration and temperature for the spinning solution of methylammonium iodide to obtain various sizes of perovskite crystallites are presented. Examples are given for some other approaches that are used in the formation of high-quality perovskite films with high optoelectronic characteristics for a conversion rate of perovskite based solar cells on them.
{"title":"Perovskite-Based Solar Cells: Some Problems and Ways of their Solution","authors":"N. Ashurov, B. Oksengendler, S. Maksimov, A. Zakhidov, G. Yar-Mukhamedova, G. Zhamanbayeva","doi":"10.18321/ectj1436","DOIUrl":"https://doi.org/10.18321/ectj1436","url":null,"abstract":"The fundamental aspects of the perovskite absorber formation of solar irradiation for two generally accepted one- and two-step technologies are considered. For the on-step variant, two stages of perovskite formation, called “through solution” and “intermediate colloid compounds of precursors”, were identified. The successive deposition of precursors is described in terms of thermodynamics and the Ostwald ripening model. The optimal conditions for the concentration and temperature for the spinning solution of methylammonium iodide to obtain various sizes of perovskite crystallites are presented. Examples are given for some other approaches that are used in the formation of high-quality perovskite films with high optoelectronic characteristics for a conversion rate of perovskite based solar cells on them.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42642855","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}
For the purpose of developing technology for the chemical processing of methane from the coal industry into valuable products, thermodynamic analysis of the major chemical reactions that occur in the multicomponent system СН4–СО2–H2O–air is carried out. The features of methane-containing gases differing from each other in chemical composition and corresponding to different stages of coal production are determined: ventilation air methane (VAM, methane concentration СCH4 less than 1 vol.%); mine/degassing methane of operating (СMM, СCH4 = 25–60 vol.%) or abandoned (AMM, СCH4 = 60–80 vol.%) coal mines; methane from unrelieved coal beds (СBM, СCH4 > 80 vol.%). Optimal conditions of the processes ensuring complete methane conversion and maximal yield of useful products are determined. The potential of combined reforming for efficient utilization of the methane-air mixture from coal mining into hydrogen-containing gas is demonstrated.
{"title":"Promising Directions in Chemical Processing of Methane from Coal Industry. Part 1. Thermodynamic analysis","authors":"E. Matus, Z. Ismagilov","doi":"10.18321/ectj1433","DOIUrl":"https://doi.org/10.18321/ectj1433","url":null,"abstract":"For the purpose of developing technology for the chemical processing of methane from the coal industry into valuable products, thermodynamic analysis of the major chemical reactions that occur in the multicomponent system СН4–СО2–H2O–air is carried out. The features of methane-containing gases differing from each other in chemical composition and corresponding to different stages of coal production are determined: ventilation air methane (VAM, methane concentration СCH4 less than 1 vol.%); mine/degassing methane of operating (СMM, СCH4 = 25–60 vol.%) or abandoned (AMM, СCH4 = 60–80 vol.%) coal mines; methane from unrelieved coal beds (СBM, СCH4 > 80 vol.%). Optimal conditions of the processes ensuring complete methane conversion and maximal yield of useful products are determined. The potential of combined reforming for efficient utilization of the methane-air mixture from coal mining into hydrogen-containing gas is demonstrated.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45301152","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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