D. Yakubik, L. R. Sadykova, Y. Zakharov, N. Zakharov, A. Popova, V. Pugachev
Calculations of the total energy of Fe-Pt nanoclusters, corresponding in the phase diagram to the compositions of FePt, FePt3 intermetallics and possessing either characteristic structures L10 and L12, respectively, or non-characteristic disordered structure A1, as well as various particle habits (cuboctahedra, icosahedra) are carried out by molecular dynamics for the first time. The dependences of cluster stability on their size and temperature are plotted, along with the schemes of temperature transformations of cluster morphology and the dependence of the melting points of the clusters with these structures and habits on their size. The size range (2–8 nm) corresponds to the sizes of particles observed by high-resolution electron microscopy. It is shown that the species play an essential part in the phase transformations proceeding under heating in the nanostructured system Fe-Pt and leading to the formation of nanocrystals with highly ordered L10 structure possessing giant coercivity are cubic nanoclusters with the ordered structures L10 and L12. With an increase in cluster size, their stability and melting points increase, tending to saturation of the dependencies within the size range above 10 nm. The least stable clusters are those of intermetallics with non-characteristic disordered structure A1 and icosahedral habit.
{"title":"Stability of FePt, FePt3 Nanoclusters of Different Habits","authors":"D. Yakubik, L. R. Sadykova, Y. Zakharov, N. Zakharov, A. Popova, V. Pugachev","doi":"10.18321/ectj1434","DOIUrl":"https://doi.org/10.18321/ectj1434","url":null,"abstract":" Calculations of the total energy of Fe-Pt nanoclusters, corresponding in the phase diagram to the compositions of FePt, FePt3 intermetallics and possessing either characteristic structures L10 and L12, respectively, or non-characteristic disordered structure A1, as well as various particle habits (cuboctahedra, icosahedra) are carried out by molecular dynamics for the first time. The dependences of cluster stability on their size and temperature are plotted, along with the schemes of temperature transformations of cluster morphology and the dependence of the melting points of the clusters with these structures and habits on their size. The size range (2–8 nm) corresponds to the sizes of particles observed by high-resolution electron microscopy. It is shown that the species play an essential part in the phase transformations proceeding under heating in the nanostructured system Fe-Pt and leading to the formation of nanocrystals with highly ordered L10 structure possessing giant coercivity are cubic nanoclusters with the ordered structures L10 and L12. With an increase in cluster size, their stability and melting points increase, tending to saturation of the dependencies within the size range above 10 nm. The least stable clusters are those of intermetallics with non-characteristic disordered structure A1 and icosahedral habit.","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":"44261149","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. N. Kuznetsov, Z. Ismagilov, L. Kuznetsova, B. Avid, X. Fan, Е.S. Mihkailova
The dissolution of bituminous coal at mild temperature was studied using a variety of commercially available coal- and petroleum-derived hydrocarbon fractions, hydrorefined derivatives and blends as solvents. The chemical and molecular composition of the coal, solvents and extracts were characterized by chemical and group analyses, and by IRFT, 1H NMR, GC-MS and liquid chromatography. Low volatile solvents like highly aromatic coal tar (CT), its anthracene fraction (AFCT), petroleum-derived solvent (HGOCC) and binary blends were found to exhibit high performance for coal dissolution into quinoline solubles (to 79‒82%), and the yields of gases being no more than 0.5%. The extracts obtained using CT and AFCT solvents represented pitch-like matter consisting of rarely substituted aromatic molecules with 4‒5 condensed rings. HGOCC extract was much less aromatic, the aromatic rings being highly substituted with fairly large alkyl substituents. The blended solvents yielded more extracts, and their molecular indexes were average between those obtained with each solvent separately. A remarkable finding was that the extracts obtained were characterized by significantly lower content of benzo(a) pyrene (BaP) compared to solvents used, its content further decreased as the time of coal dissolution increased.
{"title":"The Composition and Properties of Soluble Products from the Coal ThermoSolvolysis with Hydrocarbon Residues and Blends as Solvents","authors":"P. N. Kuznetsov, Z. Ismagilov, L. Kuznetsova, B. Avid, X. Fan, Е.S. Mihkailova","doi":"10.18321/ectj1431","DOIUrl":"https://doi.org/10.18321/ectj1431","url":null,"abstract":"The dissolution of bituminous coal at mild temperature was studied using a variety of commercially available coal- and petroleum-derived hydrocarbon fractions, hydrorefined derivatives and blends as solvents. The chemical and molecular composition of the coal, solvents and extracts were characterized by chemical and group analyses, and by IRFT, 1H NMR, GC-MS and liquid chromatography. Low volatile solvents like highly aromatic coal tar (CT), its anthracene fraction (AFCT), petroleum-derived solvent (HGOCC) and binary blends were found to exhibit high performance for coal dissolution into quinoline solubles (to 79‒82%), and the yields of gases being no more than 0.5%. The extracts obtained using CT and AFCT solvents represented pitch-like matter consisting of rarely substituted aromatic molecules with 4‒5 condensed rings. HGOCC extract was much less aromatic, the aromatic rings being highly substituted with fairly large alkyl substituents. The blended solvents yielded more extracts, and their molecular indexes were average between those obtained with each solvent separately. A remarkable finding was that the extracts obtained were characterized by significantly lower content of benzo(a) pyrene (BaP) compared to solvents used, its content further decreased as the time of coal dissolution increased.","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":"42855259","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. Seralin, G. Sugurbekova, A. Kurbanova, N. Nuraje, O. Toktarbaiuly
In this paper, it was successfully established a novel and cheap water-proofing technique for protecting concrete from further damage caused by water leakage. This technique originated from the proper design and rational formulation of the materials including hydrophobic sand, silicon oil, tyre crumb rubber, and recycled motor oil. From this research, it can be seen that only one concrete showed hydrophobicity and all obtained concrete demonstrated significantly and in some cases extremely low water permeability relative to control concrete. To the best of current knowledge, this is the first paper, which studied the surface and water sorption properties of concrete modified by the addition of hydrophobic sand obtained by patented technology. The goniometer investigated the surface properties of the modified concrete. The results obtained including density, contact angle, change of weight, and maximum load capacity under high electro-hydraulic pressure were compared and discussed.
{"title":"Designing Water-Repellent Concrete Composites Using Cheap Organic Materials","authors":"A. Seralin, G. Sugurbekova, A. Kurbanova, N. Nuraje, O. Toktarbaiuly","doi":"10.18321/ectj1438","DOIUrl":"https://doi.org/10.18321/ectj1438","url":null,"abstract":"In this paper, it was successfully established a novel and cheap water-proofing technique for protecting concrete from further damage caused by water leakage. This technique originated from the proper design and rational formulation of the materials including hydrophobic sand, silicon oil, tyre crumb rubber, and recycled motor oil. From this research, it can be seen that only one concrete showed hydrophobicity and all obtained concrete demonstrated significantly and in some cases extremely low water permeability relative to control concrete. To the best of current knowledge, this is the first paper, which studied the surface and water sorption properties of concrete modified by the addition of hydrophobic sand obtained by patented technology. The goniometer investigated the surface properties of the modified concrete. The results obtained including density, contact angle, change of weight, and maximum load capacity under high electro-hydraulic pressure were compared and discussed.","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":"42064668","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}
Y. Kraft, A.B. Aduev, N. V. Nelyubina, V. D. Volkov, Z. Ismagilov
The effect of pulsed nanosecond laser radiation (wavelength 532 nm, pulse duration 14 ns, pulse repetition frequency 6 Hz, the density of laser radiation power 0.2–0.6 J/cm2) on the tableted samples of high volatile C bituminous coal in argon medium is investigated. Among the gaseous products of pyrolysis, H2, CH4, C2H2, CO and CO2 are detected. The volume fractions of gaseous products from sample pyrolysis depending on the laser radiation power density is established. Within the laser radiation power density range 0.2–0.4 J/cm2, the volume of the formed combustible gases per unit mass of the reacted sample increases, and remains almost unchanged with further increase in power density. The volume fraction of combustible gases in the mixture of gaseous pyrolysis products are only slightly dependent on the laser radiation power density. The action of nanosecond laser radiation with a power density of more than 0.4 J/cm2 causes intense ablation of the tableted sample containing 0.005 wt.%. polyvinyl alcohol. A tableted sample containing no binding material is destroyed under the action of nanosecond laser radiation with a power density of more than 0.2 J/cm2.
{"title":"Pyrolysis of High Volatile C Bituminous Coal under the Action of Nanosecond Laser Radiation","authors":"Y. Kraft, A.B. Aduev, N. V. Nelyubina, V. D. Volkov, Z. Ismagilov","doi":"10.18321/ectj1430","DOIUrl":"https://doi.org/10.18321/ectj1430","url":null,"abstract":" The effect of pulsed nanosecond laser radiation (wavelength 532 nm, pulse duration 14 ns, pulse repetition frequency 6 Hz, the density of laser radiation power 0.2–0.6 J/cm2) on the tableted samples of high volatile C bituminous coal in argon medium is investigated. Among the gaseous products of pyrolysis, H2, CH4, C2H2, CO and CO2 are detected. The volume fractions of gaseous products from sample pyrolysis depending on the laser radiation power density is established. Within the laser radiation power density range 0.2–0.4 J/cm2, the volume of the formed combustible gases per unit mass of the reacted sample increases, and remains almost unchanged with further increase in power density. The volume fraction of combustible gases in the mixture of gaseous pyrolysis products are only slightly dependent on the laser radiation power density. The action of nanosecond laser radiation with a power density of more than 0.4 J/cm2 causes intense ablation of the tableted sample containing 0.005 wt.%. polyvinyl alcohol. A tableted sample containing no binding material is destroyed under the action of nanosecond laser radiation with a power density of more than 0.2 J/cm2.","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":"45914850","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}
Е. Matus, O. Sukhova, I. Ismagilov, V. Ushakov, S. Yashnik, M. Kerzhentsev, Z. Ismagilov
Steam/CO2 reforming of methane was studied at 600–900 °C, molar ratio CO2/H2O 0–2 and contact time 0.04–0.15 s over impregnated Ni/CeO2 catalysts of various compositions. It has been established that with an increase in the Ni content from 2 to 10 wt.%, both the conversion of reactants (X) and the yield of products (Y) increase in the range XCH4 25→80%, XCO2 35→72%, YH2 30→80%, YCO 30→75% (at 750 °C). With a further increase in the nickel content to 15%, the process parameters changed slightly, reaching a plateau. Higher nickel content (10 vs. 2 wt.%) ensures stable operation of the catalyst over time. The functional performance of the catalysts was correlated with physicochemical properties of as-synthesized, activated and spent samples using X-ray fluorescence analysis, low-temperature nitrogen adsorption, X-ray diffraction analysis, electron microscopy, and thermal analysis. It was shown that the Ni content affects the thermal stability, the textural, structural and redox characteristics of the samples. The 10% Ni/CeO2 catalyst was chosen as the optimal one due to higher H2 productivity, and sufficient resistance to sintering and coking. This sample provides a stable hydrogen yield of 85% in steam/CO2 reforming of methane at 800 °C, CO2/H2O = 2 and a contact time 0.15 s.
{"title":"Steam/CO2 Reforming of Methane Over Impregnated Ni/CeO2 Catalysts: Effect of Sample Composition on Their Activity and Stability","authors":"Е. Matus, O. Sukhova, I. Ismagilov, V. Ushakov, S. Yashnik, M. Kerzhentsev, Z. Ismagilov","doi":"10.18321/ectj1432","DOIUrl":"https://doi.org/10.18321/ectj1432","url":null,"abstract":"Steam/CO2 reforming of methane was studied at 600–900 °C, molar ratio CO2/H2O 0–2 and contact time 0.04–0.15 s over impregnated Ni/CeO2 catalysts of various compositions. It has been established that with an increase in the Ni content from 2 to 10 wt.%, both the conversion of reactants (X) and the yield of products (Y) increase in the range XCH4 25→80%, XCO2 35→72%, YH2 30→80%, YCO 30→75% (at 750 °C). With a further increase in the nickel content to 15%, the process parameters changed slightly, reaching a plateau. Higher nickel content (10 vs. 2 wt.%) ensures stable operation of the catalyst over time. The functional performance of the catalysts was correlated with physicochemical properties of as-synthesized, activated and spent samples using X-ray fluorescence analysis, low-temperature nitrogen adsorption, X-ray diffraction analysis, electron microscopy, and thermal analysis. It was shown that the Ni content affects the thermal stability, the textural, structural and redox characteristics of the samples. The 10% Ni/CeO2 catalyst was chosen as the optimal one due to higher H2 productivity, and sufficient resistance to sintering and coking. This sample provides a stable hydrogen yield of 85% in steam/CO2 reforming of methane at 800 °C, CO2/H2O = 2 and a contact time 0.15 s.","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":"49534724","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}
S. Zherebtsov, K. Shpakodraev, K. Votolin, N. Malyshenko, Z. Ismagilov
The samples of brown coal, bitumen and humic acids (HA) extracted from them are characterized by means of elemental and proximate analyses, FTIR, 13С NMR (CPMAS) spectroscopy and gas chromatography-mass spectrometry. The presence of biologically active substances is detected in the extracted bitumen samples. The biological activity of humic preparations in the form of sodium humates and the saponifiable component of the extracted bituminous resin is investigated depending on the structural-group parameters: aromaticity degree (far), the hydrophilic-hydrophobic parameter (fhh), and the parameter depicting the relationship between the aromatic and aliphatic fragments of the organic mass of HA (far/al). It is shown that O-alkylation of the organic mass of coal, followed by debituminizing, changes the structural-group composition of humic acids, causes an increase in the degree of aromaticity and leads to enhancement of the biological activity of HA.
{"title":"Structural-Group Composition and Biological Activity of Humic and Lipid Substances of Brown Coals","authors":"S. Zherebtsov, K. Shpakodraev, K. Votolin, N. Malyshenko, Z. Ismagilov","doi":"10.18321/ectj1429","DOIUrl":"https://doi.org/10.18321/ectj1429","url":null,"abstract":"The samples of brown coal, bitumen and humic acids (HA) extracted from them are characterized by means of elemental and proximate analyses, FTIR, 13С NMR (CPMAS) spectroscopy and gas chromatography-mass spectrometry. The presence of biologically active substances is detected in the extracted bitumen samples. The biological activity of humic preparations in the form of sodium humates and the saponifiable component of the extracted bituminous resin is investigated depending on the structural-group parameters: aromaticity degree (far), the hydrophilic-hydrophobic parameter (fhh), and the parameter depicting the relationship between the aromatic and aliphatic fragments of the organic mass of HA (far/al). It is shown that O-alkylation of the organic mass of coal, followed by debituminizing, changes the structural-group composition of humic acids, causes an increase in the degree of aromaticity and leads to enhancement of the biological activity of HA.","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":"46699008","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}
G. Yergaziyeva, N. Makayeva, M. Anissova, K. Dossumov, M. Mambetova, Z. Shaimerden, A. Niyazbaeva, E. Akkazin
The effect of method preparation on the activity of Fe2O3-NiO/γ-Al2O3 catalyst was investigated in process decomposition of methane. Fe2O3-NiO/γ-Al2O3 catalyst was prepared by impregnation and solution combustion methods. The samples were characterized by X-ray phase analysis (XRD), temperature-programmed hydrogen reduction (TPR-H2), BET and Raman spectroscopy. It has been shown that the method of preparation plays an important role in regulating the textural and morphological properties of catalysts and provides a difference in their catalytic activity. The synthesis of the Fe2O3-NiO/γ-Al2O3 catalyst by the solution combustion method, in comparison with the capillary impregnation method, leads to the formation of a large amount of FeNi and FeAl2O4 solid solutions, which ensured good catalytic activity at high temperatures. The Fe2O3-NiO/γ-Al2O3 catalyst synthesized by the solution combustion method demonstrated good activity with a hydrogen yield of 52% within 150 min of the reaction without any deactivation. According to the results of Raman spectroscopy, graphene-like carbon was obtained on the surface of the catalysts. On the catalyst of Fe2O3-NiO/γ-Al2O3 (СI) synthesized by capillary impregnation, 4‒5 layer graphene on Fe2O3-NiO/γ-Al2O3 (SC)-6-7 layer graphene is formed.
{"title":"Effect of Preparation Method on the Activity of Fe2O3-NiO/γ-Al2O3 Catalyst in Decomposition of Methane","authors":"G. Yergaziyeva, N. Makayeva, M. Anissova, K. Dossumov, M. Mambetova, Z. Shaimerden, A. Niyazbaeva, E. Akkazin","doi":"10.18321/ectj1435","DOIUrl":"https://doi.org/10.18321/ectj1435","url":null,"abstract":"The effect of method preparation on the activity of Fe2O3-NiO/γ-Al2O3 catalyst was investigated in process decomposition of methane. Fe2O3-NiO/γ-Al2O3 catalyst was prepared by impregnation and solution combustion methods. The samples were characterized by X-ray phase analysis (XRD), temperature-programmed hydrogen reduction (TPR-H2), BET and Raman spectroscopy. It has been shown that the method of preparation plays an important role in regulating the textural and morphological properties of catalysts and provides a difference in their catalytic activity. The synthesis of the Fe2O3-NiO/γ-Al2O3 catalyst by the solution combustion method, in comparison with the capillary impregnation method, leads to the formation of a large amount of FeNi and FeAl2O4 solid solutions, which ensured good catalytic activity at high temperatures. The Fe2O3-NiO/γ-Al2O3 catalyst synthesized by the solution combustion method demonstrated good activity with a hydrogen yield of 52% within 150 min of the reaction without any deactivation. According to the results of Raman spectroscopy, graphene-like carbon was obtained on the surface of the catalysts. On the catalyst of Fe2O3-NiO/γ-Al2O3 (СI) synthesized by capillary impregnation, 4‒5 layer graphene on Fe2O3-NiO/γ-Al2O3 (SC)-6-7 layer graphene is formed.","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":"48908656","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}
I. Sedov, V. Arutyunov, M. Tsvetkov, D. Podlesniy, M. Salganskaya, A. Zaichenko, Y. Tsvetkova, A. V. Nikitin, A. Ozerskii, I. G. Fokin, E. Salgansky
The possibility of using coalbed methane to produce methanol is assessed. Methanol can be obtained from methane both by direct partial oxidation and from synthesis gas formed through the oxidative conversion of methane. Thermodynamic analysis of coalbed methane conversion was carried out to determine the conditions for obtaining synthesis gas with the ratio [H2]/[CO] = 2, which is optimal for methanol production. The system consisting of methane, nitrogen, and oxygen, with different contents of oxygen and water vapor, was considered. The fuel-air equivalence ratio varied in the range from 2 to 4. The optimal conditions for obtaining synthesis gas for the production of methanol is the use of a mixture with an equivalence ratio of at least 4. It has also been shown that the addition of water vapor leads to an increase in the [H2]/[CO] ratio. Direct gas-phase oxidation of methane to methanol opens up the possibility of complex use of coal mining waste, including not only coalbed methane but also a large amount of coal waste accumulated during coal mining and beneficiation.
{"title":"Evaluation of the Possibility to Use Coalbed Methane to Produce Methanol Both by Direct Partial Oxidation and From Synthesis Gas","authors":"I. Sedov, V. Arutyunov, M. Tsvetkov, D. Podlesniy, M. Salganskaya, A. Zaichenko, Y. Tsvetkova, A. V. Nikitin, A. Ozerskii, I. G. Fokin, E. Salgansky","doi":"10.18321/ectj1328","DOIUrl":"https://doi.org/10.18321/ectj1328","url":null,"abstract":"The possibility of using coalbed methane to produce methanol is assessed. Methanol can be obtained from methane both by direct partial oxidation and from synthesis gas formed through the oxidative conversion of methane. Thermodynamic analysis of coalbed methane conversion was carried out to determine the conditions for obtaining synthesis gas with the ratio [H2]/[CO] = 2, which is optimal for methanol production. The system consisting of methane, nitrogen, and oxygen, with different contents of oxygen and water vapor, was considered. The fuel-air equivalence ratio varied in the range from 2 to 4. The optimal conditions for obtaining synthesis gas for the production of methanol is the use of a mixture with an equivalence ratio of at least 4. It has also been shown that the addition of water vapor leads to an increase in the [H2]/[CO] ratio. Direct gas-phase oxidation of methane to methanol opens up the possibility of complex use of coal mining waste, including not only coalbed methane but also a large amount of coal waste accumulated during coal mining and beneficiation.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43180152","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. N. Kuznetsov, O. Fetisova, L. Kuznetsova, X. Fan, B. Avid, B. Purevsuren
The chemical composition, structural and plastometric properties of typical different-ranked coals from Mongolia deposits were studied. The non-isothermal iso-conversion Ozawa-Flynn-Wall method was used to assess kinetic parameters and to differentiate decomposition steps. Key peculiarities of the pyrolysis kinetics of brown and bituminous coals were revealed and discussed in terms of the composition and plastometric properties of coals. Brown coal was shown to undergo three decomposition steps with ever increasing activation energy as temperature increased because of the decomposition of thermally more and more stable molecular fragments. The pyrolysis of bituminous coals occurred in four steps, the activation energy having an extreme mode of temperature dependence. An important new finding was that the temperature range of the second, major pyrolysis step well corresponded to that between the softening and resolidification temperatures according to Gieseler plastometry, so that the decomposition of bituminous coals at the second step proceeded in a fluid-like medium, moreover, with constant activation energy. The yield and composition of the pyrolysis products obtained under isothermal conditions were also characterized depending on coal rank and temperature, and the ways for qualified utiliza tions were offered.
{"title":"Key Peculiarities of the Pyrolysis Behavior of Different Rank Coals, and Characterization of the Pyrolysis Products","authors":"P. N. Kuznetsov, O. Fetisova, L. Kuznetsova, X. Fan, B. Avid, B. Purevsuren","doi":"10.18321/ectj1326","DOIUrl":"https://doi.org/10.18321/ectj1326","url":null,"abstract":"The chemical composition, structural and plastometric properties of typical different-ranked coals from Mongolia deposits were studied. The non-isothermal iso-conversion Ozawa-Flynn-Wall method was used to assess kinetic parameters and to differentiate decomposition steps. Key peculiarities of the pyrolysis kinetics of brown and bituminous coals were revealed and discussed in terms of the composition and plastometric properties of coals. Brown coal was shown to undergo three decomposition steps with ever increasing activation energy as temperature increased because of the decomposition of thermally more and more stable molecular fragments. The pyrolysis of bituminous coals occurred in four steps, the activation energy having an extreme mode of temperature dependence. An important new finding was that the temperature range of the second, major pyrolysis step well corresponded to that between the softening and resolidification temperatures according to Gieseler plastometry, so that the decomposition of bituminous coals at the second step proceeded in a fluid-like medium, moreover, with constant activation energy. The yield and composition of the pyrolysis products obtained under isothermal conditions were also characterized depending on coal rank and temperature, and the ways for qualified utiliza tions were offered.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47386239","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}
Z. Mansurov, G. Smagulova, A. Imash, A. Taurbekov, B. Elouadi, B. Kaidar
This article presents the results of the synthesis of carbon-NiO composite fibers. Fibers doped with NiO particles are of practical interest for applications in sensors, energy storage systems, photocatalysts, etc. Four-component initial fibers based on polyacrylonitrile (PAN), activated carbon (AC), coal tar pitch (CTP), and NiO particles were obtained. CTP was obtained by thermal treatment of coal tar, AC by carbonization of apricot kernels, NiO by solution combustion synthesis. PAN, CTP, and AC are a source of carbon, but each of them plays a specific role. PAN is the basis of carbon fibers and a fiber-forming material, CTP is a technogenic waste added to replace polymer particles, AC is an additive that could increase the carbon content and the porosity of the final fibers. The fibers were obtained using the electrospinning method, which makes it possible to use complex suspensions and obtain fibers of various diameters. PAN:CTP:AC:NiO fibers were obtained. Next, the processes of stabilization and carbonization of the fibers were carried out. The fibers at each stage were examined by scanning electron microscopy and EDAX. The result of the synthesis was carbon/NiO fibers with a diameter of 100‒300 nm. The resulting fibers are promising for practical applications due to the one-dimensional structure of the fibers and better adhesion between the fiber and NiO particles.
{"title":"Carbon/NiO Compositional Fibers","authors":"Z. Mansurov, G. Smagulova, A. Imash, A. Taurbekov, B. Elouadi, B. Kaidar","doi":"10.18321/ectj1319","DOIUrl":"https://doi.org/10.18321/ectj1319","url":null,"abstract":"This article presents the results of the synthesis of carbon-NiO composite fibers. Fibers doped with NiO particles are of practical interest for applications in sensors, energy storage systems, photocatalysts, etc. Four-component initial fibers based on polyacrylonitrile (PAN), activated carbon (AC), coal tar pitch (CTP), and NiO particles were obtained. CTP was obtained by thermal treatment of coal tar, AC by carbonization of apricot kernels, NiO by solution combustion synthesis. PAN, CTP, and AC are a source of carbon, but each of them plays a specific role. PAN is the basis of carbon fibers and a fiber-forming material, CTP is a technogenic waste added to replace polymer particles, AC is an additive that could increase the carbon content and the porosity of the final fibers. The fibers were obtained using the electrospinning method, which makes it possible to use complex suspensions and obtain fibers of various diameters. PAN:CTP:AC:NiO fibers were obtained. Next, the processes of stabilization and carbonization of the fibers were carried out. The fibers at each stage were examined by scanning electron microscopy and EDAX. The result of the synthesis was carbon/NiO fibers with a diameter of 100‒300 nm. The resulting fibers are promising for practical applications due to the one-dimensional structure of the fibers and better adhesion between the fiber and NiO particles.","PeriodicalId":11795,"journal":{"name":"Eurasian Chemico-Technological Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46475980","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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