Pub Date : 2024-09-17DOI: 10.1134/s0965544124050165
I. S. Mashkovsky, P. V. Markov, G. N. Baeva, N. S. Smirnova, A. E. Vaulina, D. P. Mel’nikov, A. Yu. Stakheev
Abstract
Two samples of PdAg/Al2O3 egg–shell single-atom catalysts, with Ag/Pd ratios of 1 : 1 and 3 : 1, were synthesized and characterized by TEM, XPS, and DRIFTS-CO methods. The formation of bimetallic PdAg alloy nanoparticles with single-atom Pd1 active sites was demonstrated. Furthermore, a physicochemical characterization showed a egg–shell distribution of the active component. The catalytic performance of the samples was tested in front-end selective hydrogenation of acetylene. The H2/C2H2 ratio in the model mixture was varied from 20 to 60. Under front-end acetylene hydrogenation conditions, the highest ethylene selectivity (about 87 at 90% acetylene conversion) was achieved in the presence of the Pd1Ag3/Al2O3 catalyst at H2/C2H2 = 20. Finally, it was shown that, unlike the monometallic Pd catalyst, the Ag-promoted catalysts were completely free of any local thermal runaway effect.
{"title":"Properties of PdAg/Al2O3 Egg–Shell Single-Atom Catalysts in Front-End Hydrogenation of Acetylene","authors":"I. S. Mashkovsky, P. V. Markov, G. N. Baeva, N. S. Smirnova, A. E. Vaulina, D. P. Mel’nikov, A. Yu. Stakheev","doi":"10.1134/s0965544124050165","DOIUrl":"https://doi.org/10.1134/s0965544124050165","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Two samples of PdAg/Al<sub>2</sub>O<sub>3</sub> egg–shell single-atom catalysts, with Ag/Pd ratios of 1 : 1 and 3 : 1, were synthesized and characterized by TEM, XPS, and DRIFTS-CO methods. The formation of bimetallic PdAg alloy nanoparticles with single-atom Pd<sub>1</sub> active sites was demonstrated. Furthermore, a physicochemical characterization showed a egg–shell distribution of the active component. The catalytic performance of the samples was tested in front-end selective hydrogenation of acetylene. The H<sub>2</sub>/C<sub>2</sub>H<sub>2</sub> ratio in the model mixture was varied from 20 to 60. Under front-end acetylene hydrogenation conditions, the highest ethylene selectivity (about 87 at 90% acetylene conversion) was achieved in the presence of the Pd<sub>1</sub>Ag<sub>3</sub>/Al<sub>2</sub>O<sub>3</sub> catalyst at H<sub>2</sub>/C<sub>2</sub>H<sub>2</sub> = 20. Finally, it was shown that, unlike the monometallic Pd catalyst, the Ag-promoted catalysts were completely free of any local thermal runaway effect.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1134/s0965544124050177
Catarina Varanda, Miguel P. Almeida, Inês Portugal, Jorge Ribeiro, Carlos M. Silva, Artur M. S. Silva
Abstract
Understanding the value of refinery by-products is crucial for assessing their potential in bitumen production. To achieve this task, the asphaltic residue, vacuum residue, and three different aromatic extracts obtained as by-products in the refining process of base oils have been characterized using various methods, including standard methods for bitumen grading (penetration, softening point, Fraass breaking point, and ageing stability), SARA analysis, proton nuclear magnetic resonance spectroscopy (1H NMR), and high-performance gel permeation chromatography (HP-GPC). Additionally, the penetration index and three significant colloidal indices based on SARA fractions have been calculated. The results show that the by-products possess distinct properties and chemical compositions. The most striking fact is that the asphaltic residue lacks saturates, while the three aromatic extracts lack asphaltenes. Due to different processing conditions, the two solvent-neutral (SN) type extracts were found to be similar, though distinct from the bright stock (BS) extract, which had a higher content of saturates and a lower content of aromatics. The comprehensive characterization of these by-products (residues and extracts) is essential for understanding their structure and planning their valorization in oil refineries, for example in the production of bitumens with specific properties. When combined with statistical and phenomenological modeling, the systematic analytical procedure presented here is useful for guiding the repurposing of oil refinery by-products.
摘要 了解炼油副产品的价值对于评估其在沥青生产中的潜力至关重要。为了完成这项任务，我们采用各种方法对基础油精炼过程中作为副产品获得的沥青渣、真空渣和三种不同的芳烃提取物进行了表征，包括沥青分级的标准方法（渗透率、软化点、弗拉斯断裂点和老化稳定性）、SARA 分析、质子核磁共振光谱（1H NMR）和高性能凝胶渗透色谱法（HP-GPC）。此外，还根据 SARA 分数计算了渗透指数和三个重要的胶体指数。结果表明，副产品具有不同的性质和化学成分。最显著的事实是沥青残渣中缺乏饱和物，而三种芳香提取物中缺乏沥青烯。由于加工条件不同，两种溶剂中性（SN）型萃取物虽然与光亮浆料（BS）萃取物有区别，但两者相似，后者的饱和物含量较高，芳香族含量较低。要了解这些副产品（残渣和萃取物）的结构并规划其在炼油厂中的利用价值，例如生产具有特定性质的沥青，就必须对这些副产品（残渣和萃取物）进行综合表征。本文介绍的系统分析程序与统计和现象建模相结合，有助于指导炼油厂副产品的再利用。
{"title":"By-Products of Arabian Light Crude Oil Refining: Profiling Properties for Bitumen Production","authors":"Catarina Varanda, Miguel P. Almeida, Inês Portugal, Jorge Ribeiro, Carlos M. Silva, Artur M. S. Silva","doi":"10.1134/s0965544124050177","DOIUrl":"https://doi.org/10.1134/s0965544124050177","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Understanding the value of refinery by-products is crucial for assessing their potential in bitumen production. To achieve this task, the asphaltic residue, vacuum residue, and three different aromatic extracts obtained as by-products in the refining process of base oils have been characterized using various methods, including standard methods for bitumen grading (penetration, softening point, Fraass breaking point, and ageing stability), SARA analysis, proton nuclear magnetic resonance spectroscopy (<sup>1</sup>H NMR), and high-performance gel permeation chromatography (HP-GPC). Additionally, the penetration index and three significant colloidal indices based on SARA fractions have been calculated. The results show that the by-products possess distinct properties and chemical compositions. The most striking fact is that the asphaltic residue lacks saturates, while the three aromatic extracts lack asphaltenes. Due to different processing conditions, the two solvent-neutral (SN) type extracts were found to be similar, though distinct from the bright stock (BS) extract, which had a higher content of saturates and a lower content of aromatics. The comprehensive characterization of these by-products (residues and extracts) is essential for understanding their structure and planning their valorization in oil refineries, for example in the production of bitumens with specific properties. When combined with statistical and phenomenological modeling, the systematic analytical procedure presented here is useful for guiding the repurposing of oil refinery by-products.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-16DOI: 10.1134/s096554412404008x
A. B. Ponomaryov, A. V. Smirnov, M. V. Shostakovsky, E. V. Pisarenko, A. G. Popov, M. A. Kashkina
Abstract
Modification of MFI-type zeolites with tin involves impregnating the zeolite with an SnCl2 solution in excess NaCl, calcination (to fix the tin oxide), and water washing (to remove excess NaCl). Loading platinum on the tin-modified support results in a highly active (5–10 mol of C3H6 per mol of Pt per second), selective (96–98% towards propylene), and stable catalyst for dehydrogenation of propane. Due to the high dispersion of tin, which serves as an anchor for platinum, the average Pt particle size is 1.2 nm. The dispersion of tin is facilitated not only by the molecular dilution of its precursor with sodium chloride but also by the redispersion of tin across the surface due to the formation of volatile SnCl4 during calcination.
{"title":"Modification of Zeolites with Tin to Synthesize Pt–Sn/MFI Catalysts for Propane Dehydrogenation","authors":"A. B. Ponomaryov, A. V. Smirnov, M. V. Shostakovsky, E. V. Pisarenko, A. G. Popov, M. A. Kashkina","doi":"10.1134/s096554412404008x","DOIUrl":"https://doi.org/10.1134/s096554412404008x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Modification of MFI-type zeolites with tin involves impregnating the zeolite with an SnCl<sub>2</sub> solution in excess NaCl, calcination (to fix the tin oxide), and water washing (to remove excess NaCl). Loading platinum on the tin-modified support results in a highly active (5–10 mol of C<sub>3</sub>H<sub>6</sub> per mol of Pt per second), selective (96–98% towards propylene), and stable catalyst for dehydrogenation of propane. Due to the high dispersion of tin, which serves as an anchor for platinum, the average Pt particle size is 1.2 nm. The dispersion of tin is facilitated not only by the molecular dilution of its precursor with sodium chloride but also by the redispersion of tin across the surface due to the formation of volatile SnCl<sub>4</sub> during calcination.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1134/s0965544124040042
N. T. Sevostyanova, S. A. Batashev
Abstract
The effects of the p-toluenesulfonic acid monohydrate (TsOH∙H2O) concentration on the alkoxycarbonylation of cyclohexene over a Pd(PPh3)2Cl2–PPh3–TsOH∙H2O catalytic system were quantified at 363–383 K. Within this temperature range, the correlation between the cyclohexyl cyclohexanecarboxylate production rate and the TsOH∙H2O concentration was found to be similar to an S-shaped curve. Based on these data, as well as previous findings with regard to the effects of water and TsOH∙H2O concentrations on the cyclohexene methoxycarbonylation rate, the hydride mechanism for the alkoxycarbonylation process was updated by adding relevant ligand exchange reactions between ballast palladium complexes, specifically reactions that produce a palladium aqua complex. The accordingly-modified kinetic equation for cyclohexene alkoxycarbonylation with cyclohexanol and CO was found to be consistent with the experimental data. Effective constants were evaluated for the modified kinetic equation over the studied temperature range. A number of relevant parameters—namely, the effective activation energy and the changes in enthalpy, entropy, and Gibbs free energy during the ligand exchange between the complexes Pd(PPh3)2(C6H11OH)2 and Pd(PPh3)2(H2O)2—were further evaluated in light of the activated complex theory. This reaction was found to be nearly equilibrium at 373 K.
摘要 在 363-383 K 的温度范围内，定量研究了对甲苯磺酸一水合物（TsOH∙H2O）浓度对 Pd(PPh3)2Cl2-PPh3-TsOH∙H2O 催化体系上环己烯烷氧基羰基化的影响。根据这些数据以及之前关于水和 TsOH∙H2O 浓度对环己烷甲氧基羰基化速率影响的研究结果，更新了烷氧基羰基化过程的氢化物机理，增加了压载钯络合物之间的相关配体交换反应，特别是产生钯水络合物的反应。相应修改后的环己烯与环己醇和 CO 进行烷氧基羰基化的动力学方程与实验数据一致。在所研究的温度范围内，对修正动力学方程的有效常数进行了评估。根据活化配合物理论，进一步评估了一些相关参数，即 Pd(PPh3)2(C6H11OH)2 和 Pd(PPh3)2(H2O)2 配合物之间配体交换过程中的有效活化能以及焓、熵和吉布斯自由能的变化。结果发现，在 373 K 时，该反应接近平衡。
{"title":"Investigation of the Dependence of the Rate of Cyclohexene Alkoxycarbonylation with Cyclohexanol and CO on the p-Toluenesulfonic Acid Monohydrate Concentration and Temperature","authors":"N. T. Sevostyanova, S. A. Batashev","doi":"10.1134/s0965544124040042","DOIUrl":"https://doi.org/10.1134/s0965544124040042","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The effects of the <i>p</i>-toluenesulfonic acid monohydrate (TsOH∙H<sub>2</sub>O) concentration on the alkoxycarbonylation of cyclohexene over a Pd(PPh<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>–PPh<sub>3</sub>–TsOH∙H<sub>2</sub>O catalytic system were quantified at 363–383 K. Within this temperature range, the correlation between the cyclohexyl cyclohexanecarboxylate production rate and the TsOH∙H<sub>2</sub>O concentration was found to be similar to an S-shaped curve. Based on these data, as well as previous findings with regard to the effects of water and TsOH∙H<sub>2</sub>O concentrations on the cyclohexene methoxycarbonylation rate, the hydride mechanism for the alkoxycarbonylation process was updated by adding relevant ligand exchange reactions between <i>ballast</i> palladium complexes, specifically reactions that produce a palladium aqua complex. The accordingly-modified kinetic equation for cyclohexene alkoxycarbonylation with cyclohexanol and CO was found to be consistent with the experimental data. Effective constants were evaluated for the modified kinetic equation over the studied temperature range. A number of relevant parameters—namely, the effective activation energy and the changes in enthalpy, entropy, and Gibbs free energy during the ligand exchange between the complexes Pd(PPh<sub>3</sub>)<sub>2</sub>(C<sub>6</sub>H<sub>11</sub>OH)<sub>2</sub> and Pd(PPh<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>—were further evaluated in light of the activated complex theory. This reaction was found to be nearly equilibrium at 373 K.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1134/s0965544124040030
P. S. Kuznetsov, K. I. Dement’ev, T. A. Palankoev, A. L. Maximov
Abstract
This review presents an analysis of the existing concepts for the utilization of electric power for heating chemical reactors, primarily those designed for heterogeneous catalytic processes. The paper provides a brief outline of major electric heating methods in the context of chemical applications, mentions important examples of the industrial implementation of electric heating, and evaluates the prospects for industrial use of electric heating instead of conventional heating systems.
{"title":"Direct Electric Heating in Chemical Processes (A Review)","authors":"P. S. Kuznetsov, K. I. Dement’ev, T. A. Palankoev, A. L. Maximov","doi":"10.1134/s0965544124040030","DOIUrl":"https://doi.org/10.1134/s0965544124040030","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This review presents an analysis of the existing concepts for the utilization of electric power for heating chemical reactors, primarily those designed for heterogeneous catalytic processes. The paper provides a brief outline of major electric heating methods in the context of chemical applications, mentions important examples of the industrial implementation of electric heating, and evaluates the prospects for industrial use of electric heating instead of conventional heating systems.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1134/s0965544124040078
G. P. Kayukova, N. M. Khasanova, A. N. Mikhailova, Z. R. Nasyrova, A. V. Vakhin
Abstract
Thermochemical transformations of the organic matter and mineral matrix of the bituminous oil-containing rock from the productive stratum of Permian heavy crude deposits (Ashal’cha oilfield) at 350 and 600°С in a hydrogen medium were studied by electron paramagnetic resonance (EPR) spectroscopy. A rock sample taken from a depth of 117.5–118.5 m was studied before and after hydrothermal treatment at 300°С in the presence of an aqueous phase. Comparison of the EPR spectra shows that, as compared to the initial rock, an increase in the temperature to the “oil window” level, 350°С, leads to a fourfold increase in the intensity of the signal from free organic radicals (С350), and after hydrothermal treatment its intensity increases by a factor of 5. This fact characterizes the oil-generation potential of the rock with the formation of liquid and gaseous hydrocarbons. On reaching the “oil and gas window” temperature (600°С), organic carbon radicals (С600) were not detected. This fact suggests that the rock from productive deposits of the Permian age virtually completely realizes its oil-generation potential at 350°C. The amount of Mn2+ ions in calcite after the hydrothermal treatment gradually decreases with an increase in the pyrolysis temperature. Iron oxides and hydroxides were detected as concomitant compounds. They can exhibit catalytic properties in hydrothermal and pyrolytic processes. The presence of minerals of iron and manganese in different oxidation states suggests nonequilibrium conditions of the rock alteration. Thus, EPR can serve as a nondestructive method for simultaneous monitoring of the mineral composition and organic matter of rocks.
{"title":"An EPR Study of the Effect of Thermochemical Processes on the Transformations of the Organic Matter and Mineral Matrix of a Bituminous Rock","authors":"G. P. Kayukova, N. M. Khasanova, A. N. Mikhailova, Z. R. Nasyrova, A. V. Vakhin","doi":"10.1134/s0965544124040078","DOIUrl":"https://doi.org/10.1134/s0965544124040078","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Thermochemical transformations of the organic matter and mineral matrix of the bituminous oil-containing rock from the productive stratum of Permian heavy crude deposits (Ashal’cha oilfield) at 350 and 600°С in a hydrogen medium were studied by electron paramagnetic resonance (EPR) spectroscopy. A rock sample taken from a depth of 117.5–118.5 m was studied before and after hydrothermal treatment at 300°С in the presence of an aqueous phase. Comparison of the EPR spectra shows that, as compared to the initial rock, an increase in the temperature to the “oil window” level, 350°С, leads to a fourfold increase in the intensity of the signal from free organic radicals (С<sub>350</sub>), and after hydrothermal treatment its intensity increases by a factor of 5. This fact characterizes the oil-generation potential of the rock with the formation of liquid and gaseous hydrocarbons. On reaching the “oil and gas window” temperature (600°С), organic carbon radicals (С<sub>600</sub>) were not detected. This fact suggests that the rock from productive deposits of the Permian age virtually completely realizes its oil-generation potential at 350°C. The amount of Mn<sup>2+</sup> ions in calcite after the hydrothermal treatment gradually decreases with an increase in the pyrolysis temperature. Iron oxides and hydroxides were detected as concomitant compounds. They can exhibit catalytic properties in hydrothermal and pyrolytic processes. The presence of minerals of iron and manganese in different oxidation states suggests nonequilibrium conditions of the rock alteration. Thus, EPR can serve as a nondestructive method for simultaneous monitoring of the mineral composition and organic matter of rocks.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1134/s0965544124040054
V. A. Tuskaev, D. A. Kurmaev, S. Ch. Gagieva, M. D. Evseeva, M. I. Buzin, E. K. Golubev, B. M. Bulychev
Abstract
It was shown by EPR spectroscopy that Ti(IV) was gradually reduced to Ti(III) when a titanium(IV) dichloride complex with a saligenin ligand was used as a model pre-catalyst in the presence of (EtnAlCl3–n + Bu2Mg) as an activator. Pre-activation of this complex (by stirring in an inert atmosphere with a half-load of the Al/Mg activator before being introduced into the reactor) significantly (about twofold) enhanced its catalytic activity, up to 4100 kgPE molTi–1 h–1 atm–1. All the synthesized polyethylene samples were linear ultrahigh-molecular-weight polymers (UHMWPEs) with Mv = 1.0–3.5×106 g/mol. This pre-activation technique was further employed to test a series of Al/Mg activators that differed in the nature of their organometallic compounds and in their Al/Mg molar ratio. The test data suggest that the catalytic system under study had active sites with titanium being present mainly in the oxidation state of +3. Most samples of UHMWPE produced with the pre-activated complex proved suitable for solvent-free processing into high-strength oriented films.
{"title":"Binary Mixtures (AlknAlCl3–n + Alk2Mg) as Catalyst Components for Ethylene Polymerization and the Role of Titanium Oxidation State in Their Catalytic Activity","authors":"V. A. Tuskaev, D. A. Kurmaev, S. Ch. Gagieva, M. D. Evseeva, M. I. Buzin, E. K. Golubev, B. M. Bulychev","doi":"10.1134/s0965544124040054","DOIUrl":"https://doi.org/10.1134/s0965544124040054","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>It was shown by EPR spectroscopy that Ti(IV) was gradually reduced to Ti(III) when a titanium(IV) dichloride complex with a saligenin ligand was used as a model pre-catalyst in the presence of (Et<sub><i>n</i></sub>AlCl<sub>3–<i>n</i></sub> + Bu<sub>2</sub>Mg) as an activator. Pre-activation of this complex (by stirring in an inert atmosphere with a half-load of the Al/Mg activator before being introduced into the reactor) significantly (about twofold) enhanced its catalytic activity, up to 4100 kg<sub>PE</sub> mol<sub>Ti</sub><sup>–1</sup> h<sup>–1</sup> atm<sup>–1</sup>. All the synthesized polyethylene samples were linear ultrahigh-molecular-weight polymers (UHMWPEs) with M<sub>v</sub> = 1.0–3.5×10<sup>6</sup> g/mol. This pre-activation technique was further employed to test a series of Al/Mg activators that differed in the nature of their organometallic compounds and in their Al/Mg molar ratio. The test data suggest that the catalytic system under study had active sites with titanium being present mainly in the oxidation state of +3. Most samples of UHMWPE produced with the pre-activated complex proved suitable for solvent-free processing into high-strength oriented films.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1134/s0965544124040029
N. S. Burdelnaya, D. A. Bushnev, A. A. Ilchenko
Abstract
A series of kerogen samples were isolated from Domanik oil shale before and after hydrothermal treatment in an autoclave (at 250–375°C, for 24 h). Than composition of the C1–C5 hydrocarbon gases generated in stepwise (300–800°C) pyrolysis of these kerogens was characterized by gas chromatography. According to the calculated EASY %Ro and Rock-Eval pyrolysis data, the highest maturity level of the organic matter reached by the hydrothermal treatment corresponded to the MC4 stage. As the hydrothermal treatment temperature of the oil shale was elevated up to 325°C, the dry pyrolysis of residual kerogen led to the predominant generation of wet gases in which C2+ prevailed over methane; at temperatures above 325°C, methane was predominant. Based on the pattern of the generation curves plotted individually for C1, C2, C3, C2–C5, and C4–C5 gases, methane was found to have additional sources in the kerogen structure, compared to C2+ gases. Ethane and ethylene are generated simultaneously via the free-radical decomposition of alkyl structures; moreover, at high pyrolysis temperatures, ethane and ethylene have some precursors other than those of C3+ gases.
{"title":"Generation of Hydrocarbon Gases in Stepwise Pyrolysis of Artificially Matured Domanik Oil Shale Kerogen","authors":"N. S. Burdelnaya, D. A. Bushnev, A. A. Ilchenko","doi":"10.1134/s0965544124040029","DOIUrl":"https://doi.org/10.1134/s0965544124040029","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A series of kerogen samples were isolated from Domanik oil shale before and after hydrothermal treatment in an autoclave (at 250–375°C, for 24 h). Than composition of the C<sub>1</sub>–C<sub>5</sub> hydrocarbon gases generated in stepwise (300–800°C) pyrolysis of these kerogens was characterized by gas chromatography. According to the calculated EASY %Ro and Rock-Eval pyrolysis data, the highest maturity level of the organic matter reached by the hydrothermal treatment corresponded to the MC<sub>4</sub> stage. As the hydrothermal treatment temperature of the oil shale was elevated up to 325°C, the dry pyrolysis of residual kerogen led to the predominant generation of wet gases in which C<sub>2+</sub> prevailed over methane; at temperatures above 325°C, methane was predominant. Based on the pattern of the generation curves plotted individually for C<sub>1</sub>, C<sub>2</sub>, C<sub>3</sub>, C<sub>2</sub>–C<sub>5</sub>, and C<sub>4</sub>–C<sub>5</sub> gases, methane was found to have additional sources in the kerogen structure, compared to C<sub>2+</sub> gases. Ethane and ethylene are generated simultaneously <i>via</i> the free-radical decomposition of alkyl structures; moreover, at high pyrolysis temperatures, ethane and ethylene have some precursors other than those of C<sub>3+</sub> gases.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1134/s0965544124040017
Yu. V. Loskutova, N. V. Sizova, N. V. Yudina
Abstract
The effect of low-frequency acoustic treatment and of constant and alternating electromagnetic fields on the reactivity of crude oil and resin–asphaltene components was studied. Irrespective of the kind of the wave treatment, the amount of asphaltenes and resins separated from the treated oil decreases owing the breakdown of aggregates of complex structural units with the release of hydrocarbons of various structures, occluded in the molecular complexes, into the liquid phase. The treatment involves cleavage of weak hydrogen bonds with the formation of additional reaction sites in paramagnetic asphaltenes and diamagnetic resins. The reactivity of both crude oil and the separated resin and asphaltene fractions significantly changes owing to the formation of new reactive structures in the physical fields. These structures differ not only in the size and structure but also in the antioxidant properties. The data obtained allow more detailed evaluation of the effect exerted by various kinds of wave treatment on the composition and structure of asphaltenes and resins of heavy high-viscosity crude.
{"title":"Effect of Wave Treatment on the Antioxidant Activity of Resins and Asphaltenes of Heavy High-Viscosity Crude Oil","authors":"Yu. V. Loskutova, N. V. Sizova, N. V. Yudina","doi":"10.1134/s0965544124040017","DOIUrl":"https://doi.org/10.1134/s0965544124040017","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The effect of low-frequency acoustic treatment and of constant and alternating electromagnetic fields on the reactivity of crude oil and resin–asphaltene components was studied. Irrespective of the kind of the wave treatment, the amount of asphaltenes and resins separated from the treated oil decreases owing the breakdown of aggregates of complex structural units with the release of hydrocarbons of various structures, occluded in the molecular complexes, into the liquid phase. The treatment involves cleavage of weak hydrogen bonds with the formation of additional reaction sites in paramagnetic asphaltenes and diamagnetic resins. The reactivity of both crude oil and the separated resin and asphaltene fractions significantly changes owing to the formation of new reactive structures in the physical fields. These structures differ not only in the size and structure but also in the antioxidant properties. The data obtained allow more detailed evaluation of the effect exerted by various kinds of wave treatment on the composition and structure of asphaltenes and resins of heavy high-viscosity crude.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1134/s0965544124040066
Kahina Bedda
Abstract
An artificial neural network (ANN) model of a multilayer perceptron-type was developed to predict flash points of petroleum middle distillates. The ANN model was designed using 252 experimental data points taken from the literature. The properties of the distillates, namely, specific gravity and distillation temperatures, were the input parameters of the model. The training of the network was carried out using the Levenberg– Marquardt backpropagation algorithm and the early stopping technique. A comparison of the statistical parameters of different networks made it possible to determine the optimal number of neurons in the hidden layer with the best weight and bias values. The network containing nine hidden neurons was selected as the best predictive model. The ANN model as well as the Alqaheem–Riazi’s model was evaluated for the prediction of flash points by a statistical analysis based on the calculation of the mean square error, Pearson correlation coefficient, coefficient of determination, absolute percentage errors, and the mean absolute percentage error. The ANN model provided higher prediction accuracy over a wide distillation range than the Alqaheem–Riazi’s model. The developed ANN model is a reliable and fast tool for the low-cost estimation of flash points of petroleum middle distillates.
摘要 开发了一种多层感知器型人工神经网络（ANN）模型，用于预测石油中间馏分的闪点。ANN 模型是利用文献中的 252 个实验数据点设计的。馏分油的特性，即比重和馏分温度，是模型的输入参数。使用 Levenberg- Marquardt 反向传播算法和早期停止技术对网络进行了训练。通过比较不同网络的统计参数，确定了具有最佳权值和偏置值的隐层神经元的最佳数量。包含九个隐藏神经元的网络被选为最佳预测模型。通过计算均方误差、皮尔逊相关系数、决定系数、绝对百分比误差和平均绝对百分比误差等统计分析，对 ANN 模型和 Alqaheem-Riazi 模型进行了闪光点预测评估。与 Alqaheem-Riazi 模型相比，ANN 模型在较宽的蒸馏范围内提供了更高的预测精度。所开发的 ANN 模型是低成本估算石油中间馏分闪点的可靠而快速的工具。
{"title":"Prediction of Flash Points of Petroleum Middle Distillates Using an Artificial Neural Network Model","authors":"Kahina Bedda","doi":"10.1134/s0965544124040066","DOIUrl":"https://doi.org/10.1134/s0965544124040066","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>An artificial neural network (ANN) model of a multilayer perceptron-type was developed to predict flash points of petroleum middle distillates. The ANN model was designed using 252 experimental data points taken from the literature. The properties of the distillates, namely, specific gravity and distillation temperatures, were the input parameters of the model. The training of the network was carried out using the Levenberg– Marquardt backpropagation algorithm and the early stopping technique. A comparison of the statistical parameters of different networks made it possible to determine the optimal number of neurons in the hidden layer with the best weight and bias values. The network containing nine hidden neurons was selected as the best predictive model. The ANN model as well as the Alqaheem–Riazi’s model was evaluated for the prediction of flash points by a statistical analysis based on the calculation of the mean square error, Pearson correlation coefficient, coefficient of determination, absolute percentage errors, and the mean absolute percentage error. The ANN model provided higher prediction accuracy over a wide distillation range than the Alqaheem–Riazi’s model. The developed ANN model is a reliable and fast tool for the low-cost estimation of flash points of petroleum middle distillates.</p>","PeriodicalId":725,"journal":{"name":"Petroleum Chemistry","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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