Heat Treatment Condition Influence on Novokuibyshevsk Vacuum Residue Component Composition

The article presents the information about thermal degradation of Novokuibyshevsk vacuum residue and change of products composition during this process. The optimal conditions for the thermal destruction of vacuum residue components were established. The regularities of material balance composition change, Sgeneral were determined depending on cracking conditions. The basic directions of resin-asphaltene component transformations were identified, changes in their structural-group parameters in the process of initiated cracking were analyzed. Conducting of Novokuibyshevsk vacuum residue thermolysis leads to deep resins-asphaltenes average molecules structure characteristic changes. Developed alkyl and naphthenic moieties, which are presented in initial molecule, undergo degradation, amount of structural blocks in resins and asphaltenes molecules reduces, their average size decreases. Also the reduction in total content of the rings (saturated and aromatic) was established in average structural unit, at the same time decrease of rings substitution and length of the aliphatic fragments can be observed. In general the process of vacuum residue thermal cracking causes partial degradation of saturated (aliphatic and naphthenic) fragments and, partially, aromatic rings, which contain heteroatomic elements

Heat Treatment Condition Influence on Novokuibyshevsk Vacuum Residue Component Composition

The article presents the information about thermal degradation of Novokuibyshevsk vacuum residue and change of products composition during this process. The optimal conditions for the thermal destruction of vacuum residue components were established. The regularities of material balance composition change, Sgeneral were determined depending on cracking conditions. The basic directions of resin-asphaltene component transformations were identified, changes in their structural-group parameters in the process of initiated cracking were analyzed. Conducting of Novokuibyshevsk vacuum residue thermolysis leads to deep resins-asphaltenes average molecules structure characteristic changes. Developed alkyl and naphthenic moieties, which are presented in initial molecule, undergo degradation, amount of structural blocks in resins and asphaltenes molecules reduces, their average size decreases. Also the reduction in total content of the rings (saturated and aromatic) was established in average structural unit, at the same time decrease of rings substitution and length of the aliphatic fragments can be observed. In general the process of vacuum residue thermal cracking causes partial degradation of saturated (aliphatic and naphthenic) fragments and, partially, aromatic rings, which contain heteroatomic elements

Recent advances in the electrochemical synthesis of organosulfur compounds

Organosulfur compounds are being widely used in medicinal chemistry, as well as in organic transformations and in synthetic applications. Because of their interest in many areas, the development of sustainable and green synthetic methods to access various organosulfur compounds has a high influence on the chemistry community. Electroorganic synthesis has become a very valuable methodology for the synthesis of organosulfur compounds during the last decade. The use of electrochemical technology offers a green, sustainable and safe alternative to prepare and modify such compounds. This review summarises recent developments in the preparation of organosulfur compounds such as sulfoxides, sulfones, sulfinic esters, sulfonamides, thiosulfonates, sulfonyl fluorides and sulfoximines under electrochemical reaction conditions

Development of Alternative Methods to Assess the Toxicity and Bioaccumulation Potential of Chemicals in the Aquatic Environment

The toxicity and bioaccumulation potential of chemicals are properties that need to be assessed in risk assessment. In the context of the aquatic environment, both properties were traditionally evaluated in the whole fish. However, due to the reluctance to use a large number of animals for experimentation and high cost of in vivo testing, alternative techniques have been developed to assess these properties. This thesis describes three distinct investigations towards the development of alternative methods for predicting the toxicity and bioaccumulation potential of chemicals. The first study of this thesis is centred on the development of a list of reference compounds to evaluate non-animal methods to in vivo bioaccumulation studies in fish. The selection of representative chemicals was developed following a novel strategy built from previous criteria proposed for the validation of experimental tests and considering relevant aspects for the bioaccumulation of organic chemicals. A revision and a comparison of the most used alternative approaches to in vivo bioaccumulation studies were undertaken in this thesis. In particular, a variety of in vitro and in silico methods were explored and compared in terms of their reliability to predict the whole body biotransformation rate and bioconcentration factor of chemicals in fish. As a consequence of this investigation, an insight into the main challenges and future perspectives for each of the methods evaluated was conducted to provide a foundation for future research. The last research study is focused on the verification of the prediction of protein binding for cyclic compounds and the development of a decision tree strategy to prioritise chemicals for in vivo toxicity testing. The last two objectives were developed based on the integration of different alternative methods to assess the toxicity of chemicals. This thesis concludes with a summary and a discussion of the work undertaken and suggestions for future work

Oxidative desulfurization of fuel oils-catalytic oxidation and adsorptive removal of organosulfur compounds

The syntheses and evaluation of oxidovanadium(IV) complexes as catalysts for the oxidation of refractory organosulfur compounds in fuels is presented. The sulfones produced from the oxidation reaction were removed from fuel oils by employing molecularly imprinted polymers (MIPs). The oxidovanadium(IV) homogeneous catalyst, [V ͥ ͮ O(sal-HBPD)], as well as its heterogeneous polymer supported derivatives, poly[V ͥ ͮ O(sal-AHBPD)] and poly[V ͥ ͮ O(allylSB-co-EGDMA)], were synthesized and fully characterized by elemental analysis, FTIR, UV-Vis, XPS, AFM, SEM, BET and single crystal XRD for [V ͥ ͮ O(sal-HBPD)]. The MIPs were also characterized by elemental analysis, FTIR, SEM, EDX and BET. The catalyzed oxidation of fuel oil model sulfur compounds, thiophene (TH), benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT), was conducted under batch and continuous flow processes at 40°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant. The continuous flow oxidation process presented the highest overall conversions and very high selectivity for sulfones. Maximum oxidation conversions of 71%, 89%, 99% and 88% was achieved for TH, BT, DBT and 4,6-DMDBT respectively when poly[V ͥ ͮ O(allylSB-co-EGDMA)] was employed at a flow-rate of 1 mL/h with over 90% sulfone selectivity. The process was further applied to the oxidation of hydro-treated diesel containing 385 ± 4.6 ppm of sulfur (mainly dibenzothiophene and dibenzothiophene derivatives), and this resulted to a high sulfur oxidation yield (> 99%), thus producing polar sulfones which are extractible by polar solid phase extractants. Adsorption of the polar sulfone compounds was carried-out by employing MIPs which were fabricated through the formation of recognition sites complementary to oxidized sulfur-containing compounds (sulfones) on electrospun polybenzimidazole (PBI) nanofibers, cross-linked chitosan microspheres and electrospun chitosan nanofibers. Adsorption of benzothiophene sulfone (BTO₂), dibenzothiophene sulfone (DBTO₂) and 4,6-dimethyldibenzothiophene sulfone (4,6-DMDBTO₂) on the various molecularly imprinted adsorbents presented a Freundlich (multi-layered) adsorption isotherm which indicated interaction of adsorbed organosulfur compounds. Maximum adsorption observed for BTO₂, DBTO₂ and 4,6-DMDBTO₂ respectively was 8.5 ± 0.6 mg/g, 7.0 ± 0.5 mg/g and 6.6 ± 0.7 mg/g when imprinted chitosan nanofibers were employed, 4.9 ± 0.5 mg/g, 4.2 ± 0.7 mg/g and 3.9 ± 0.6 mg/g on molecularly imprinted chitosan microspheres, and 28.5 ± 0.4 mg/g, 29.8 ± 2.2 mg/g and 20.1 ± 1.4 mg/g on molecularly imprinted PBI nanofibers. Application of electrospun chitosan nanofibers on oxidized hydro-treated diesel presented a sulfur removal capacity of 84%, leaving 62 ± 3.2 ppm S in the fuel, while imprinted PBI electrospun nanofibers displayed excellent sulfur removal, keeping sulfur in the fuel after the oxidation/adsorption below the determined limit of detection (LOD), which is 2.4 ppm S. The high level of sulfur removal displayed by imprinted PBI nanofibers was ascribed to hydrogen bonding effects, and π-π stacking between aromatic sulfone compounds and the benzimidazole ring which were confirmed by chemical modelling with density functional theory (DFT) as well as the imprinting effect. The home-made pressurized hot water extraction (PHWE) system was applied for extraction/desorption of sulfone compounds adsorbed on the PBI nanofibers at a flow rate of 1 mL/min and at 150°C with an applied pressure of 30 bars. Application of molecularly imprinted PBI nanofibers for the desulfurization of oxidized hydro-treated fuel showed potential for use in refining industries to reach ultra-low sulfur fuel level, which falls below the 10 ppm sulfur limit which is mandated by the environmental protection agency (EPA) from 2015

Перспективы развития фундаментальных наук: сборник научных трудов XI Международной конференция студентов и молодых ученых, г. Томск, 22-25 апреля 2014 г.

Сборник содержит труды участников XI Международной конференции студентов и молодых учёных "Перспективы развития фундаментальных наук". Включает доклады студентов и молодых ученых, представленные на секциях "физика", "химия", "математика", "технология", наноматериалы и нанотехнологии», "IT-технологии и электроника". В рамках секций представлены доклады студентов представленные для соискания стипендий по программе У.М.Н.И.К. Сборник представляет интерес для студентов, аспирантов, молодых ученых, преподавателей в области естественных наук и высшей математик

Проблемы геологии и освоения недр. Т. 2

В сборнике отражены проблемы палеонтологии, стратиграфии, тектоники, исторической и региональной геологии, минералогии, геохимии, петрологии, литологии, полезных ископаемых, металлогении, гидрогеологии, гидрогеохимии, инженерной геологии, геофизики, нефтяной геологии, геоинформационных систем в геологии, космогеологических исследований, разработки нефтяных и газовых месторождений, переработки углеводородного и минерального сырья, нефтегазопромыслового оборудования, бурения нефтяных и газовых скважин, техники и технологии разведки и добычи, транспорта и хранения нефти и газа, горного дела, технологии и техники разведки месторождений полезных ископаемых, геоэкологии, гидрогеоэкологии, охраны и инженерной защиты окружающей среды, комплексного использования минерального сырья, землеустройства, экономики минерального сырья и горного права. Публикация сборника трудов XVIII Международного научного симпозиума осуществляется при информационной поддержке Министерства образования и науки РФ (Роснаука) и при поддержке Российского фонда фундаментальных исследований РФ

Перспективы развития фундаментальных наук: сборник научных трудов XI Международной конференция студентов и молодых ученых, г. Томск, 22-25 апреля 2014 г.

Сборник содержит труды участников XI Международной конференции студентов и молодых учёных "Перспективы развития фундаментальных наук". Включает доклады студентов и молодых ученых, представленные на секциях "физика", "химия", "математика", "технология", наноматериалы и нанотехнологии», "IT-технологии и электроника". В рамках секций представлены доклады студентов представленные для соискания стипендий по программе У.М.Н.И.К. Сборник представляет интерес для студентов, аспирантов, молодых ученых, преподавателей в области естественных наук и высшей математик

Oxidative Desulfurization II: Temperature Dependence of Organosulfur Compounds Oxidation

In this work the oxidation of benzo-, dibenzo-, 4-methyldibenzo-, and 4,6-dimethyildibenzothiophene in the presence of hydrogen peroxide and formic acid was studied over the temperature range of 20-65 degrees C. The experimental data were interpreted by means of a interfacial mass transfer and reaction model developed in the first part of this study. The parameters identification tool available in gPROMS environment allowed a regression of the Arrhenius constants of the rate determining step characterizing the considered oxidation reactions. The activation energies of the thiophenes oxidation reactions result in 34.6 kJ/mol and 29 +/- 1 kJ/mol for BT and DBTs, respectively