The influence of pyrolysis conditions on hydrocarbons composition of the shale oil (Aleksinac oil shale, Serbia)

The amount and the composition of liquid hydrocarbons (HCs) obtained by pyrolysis of oil shale depend on kerogen type, as well as pyrolytic system and conditions [1]. The aim of this study was to compare HCs composition of bitumen isolated from raw oil shale samples (osh) and shale oils obtained by pyrolysis of oil shales in an open system (os) and close system (cs) (Table 1). Investigation has been made on immature outcrop oil shale samples (vitrinite reflectance of 0.41 % Rr) from the Aleksinac deposit (Serbia). Pyrolysis experiments were performed on the two selected samples, which have shown the highest quantity of total organic carbon (TOC > 13 %) and high HCs generation potential (Hydrogen Index, HI > 615 mg HCs/g TOC) in the studied sample set [2]. The HCs composition of the shale oils obtained by open system pyrolysis indicates low maturity. They are similar to distributions of HCs in bitumens isolated from raw (initial) oil shales (Table 1). Therefore open system pyrolysis can be useful for assessment of source and depositional environment of organic matter. On the other head, shale oils obtained by pyrolysis in the close system have distributions of HCs which correspond to higher maturity and they are similar to composition of HCs in crude oil, generated in early stage of “oil window” (Table 1). Therefore, for artificial generation of shale oil (from immature oil shale), having composition comparable to crude oil, the close system pyrolysis is required. CPI – Carbon Preference Index, calculated from distributions of n-alkanes; Rc – calculated vitrinite reflectance = 0.49 x C29ααα20S/20R + 0.33; / – Not determined due to the absence of C29 αββ 20Rsterane in these samples

Geochemical and Sedimentation History of Neogene Lacustrine Sediments from the Valjevo-Mionica Basin (Serbia)

Valjevo-Mionica Basin is one of the numerous lacustrine Neogene basins in Serbia. After Aleksinac Basin, according to the quality and amount of oil shale, it is one of the main deposits of this raw material in Serbia. The most important oil shale deposits in Valjevo- Mionica Basin are located in the central part of the basin (Bela stena series, Sušeočka and Radobićka Bela Stena). The kerogen content in oil shales ranged from 8 - 16 %. The average oil yield of 6.3 % is of economical value. Total of 62 samples of Neogene lacustrine sedimentary rocks to the depth of 400 m were investigated in this study. The first objective of the study was to reconstruct geological history (evolution) of the sediments i.e. to determine the palaeoconditions in depositional environment during its formation. For this purpose numerous geochemical methods and approaches were used. The second objective of the study was to determine the origin, type, maturity and liquid hydrocarbon potential of organic matter (OM). Aimed at detailed estimation of the oil shale OM potential, and prediction of the conditions necessary to become active oil generating source rock, pyrolytic experiments were performed on the bitumen-free sample. Bearing in mind that some metal ions (e.g. Al(III)-ion in clay minerals) (Jovančićević et al., 1993; Peters et al., 2005) have catalytic influence on most of the maturation processes, and that Pt(IV)- and Ru(III)- ions are often components of catalysts in many laboratory investigations and industrial procedures (Hu et al., 1994; Kawaguchi et al., 2005), the pyrolytic experiments of bitumen-free rock were performed also in the presence of simple inorganic compounds, H2[PtCl6] and RuCl3, to investigate if their presence changes the yield and hydrocarbon composition of liquid pyrolysates

Исследование напряженно-деформированного состояния нелинейных участков магистрального газопровода Карталы-Астана

A petrological and organic geochemical study was performed on coal samples from the East field deposit, Bogovina Basin, Serbia. Fourteen coal samples were collected from different parts of the Main and Upper coal seams from fresh, working faces in the underground subbituminous coal mine. The Lower Miocene (?) coal of the East field is a typical humic coal with huminite, liptinite and inertinite concentrations of up to 81.4 vol.%, 16.1 vol.% and 13.5 vol.%, respectively. Densinite is the most abundant maceral with variable amounts of ulminite and gelinite. Sporinite and liptodetrinite are the most common macerals of the liptinite group. Exsudatinite was detected in the lower part of the Lower coal seam. Inertodetrinite is the most abundant maceral of the inertinite group. The mineral matter consists mostly of clay minerals and carbonates. The mean random huminite reflectance (ulminite B) for the Main coal seam is 0.42 +/- 0.04%Rr, and 0.41 +/- 0.04%Rr for the Upper coal seam, which are typical for an immature to early mature stage of the organic matter. The distribution and abundance of n-alkanes and steranes indicates a significant contribution of epicuticular waxes from higher plants. High amount of phyllocladane-type diterpenoids (16 alpha(H)-phyllocladane) suggests that coal forming plants were conifer families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Sciadopityaceae, and Phyllocladaceae, while a higher amount of pimarane and norpimarane suggests Pinaceae. Taxodiaceae, and Cupressaceae. The pristane/phytane (Pr/Ph) ratio implies variable anaerobic to oxic conditions during sedimentation. The distribution of the hopanes detected in the Bogovina East field coal indicates an immature to early mature stage of the organic matter, which is in agreement with huminite reflectance. The high coal sulphur contents from the East field are characteristic for slightly alkaline depositional environments generated by bentonite from the basement of the Main coal seam. The petrological observation and biomarker composition provide evidence for the generation of immature hydrocarbons which, most probably, originated from the resins and waxes of higher plants, mostly gymnosperms. (C) 2009 Elsevier B.V. All rights reserved

Molecular and isotope composition of biomarkers in immature oil shale and its liquid pyrolysis products (open and closed system).

The molecular and isotopic composition of biomarkers in initial bitumen isolated from raw immature oil shale samples from the Lower Miocene Aleksinac Basin (Serbia) and liquid products (LPs) obtained by pyrolysis in open (OS) and closed systems (CS) are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in LPs is determined. The molecular composition of the LPs from the OS pyrolysis is very similar to those in initial bitumen, independently on kerogen type. The LPs from the CS pyrolysis have the distributions of biomarkers similar to those in crude oils generated in an early to main stage of “oil window“. The biomarker data suggests that mixed type I/II kerogen attained slightly higher maturity level by the CS pyrolysis than type I kerogen. The isotopic signatures of n-alkanes in LPs obtained by the OS pyrolysis are isotopically lighter than in initial bitumen, independently on kerogen type, whereas in liquid products from the CS they become heavier; showing more pronounced difference for type I kerogen. The results indicate that δ13C data should be used with caution in interpretation of samples having different maturity and particularly of LPs obtained by different system pyrolysis

Heavy metals in Neogene sedimentary rocks as a potential geogenic hazard for sediment, soil, and surface and groundwater contamination (eastern Posavina and the Lopare Basin, Bosnia and Herzegovina)

The influence of geochemical processes (weathering, erosion and dilution) of the Internal Dinarides to the Posavina Neogene Basin and their implication to the pollution of the Sava River sediments at four sampling sites in the Eastern Posavina (Zupanja, Brcko, Bosanska Raca and Sremska Mitrovica) was studied.(similar to)For this purpose, comparison of contents of heavy metals (Pb, Zn, Cu, Ni, Cr, Cd, As and Hg) of the Eastern Posavina sediments with local background values was performed. Sediments from two boreholes of the Lopare Basin considered as non-polluted and representative for specific geologic and hydrogeologic system were used for the calculation of local background values. The aim was to assess whether the observed heavy metals concentrations at four sampling sites along the Sava River represent background/natural or anthropogenic contamination. This task was performed using the geo-accumulation index and total enrichment factor. According to values of the total enrichment factor (0.25-0.71), the anthropogenic impact on the investigated area was quite low. The heavy metals contents in river sediments, soil and groundwater were mainly controlled by geochemical processes, particularly weathering (chemical proxy of alteration value approximate to 60). The results also offer novel insights into the elevated geogenic levels of Cr and Ni in the Eastern Posavina region

Determination of Extractable Organic Matter Type from Urban Sediments of Vrbas River (Banja Luka, Bosnia and Herzegovina)

The Vrbas River is an important river ecosystem in Bosnia and Herzegovina with a length of 250 km and catchment areas of 5900 km2 . Before reaching Banja Luka, the Vrbas River passes through a canyon and numerous gorges, which are from 1955 protected by the Law on the Protection of Natural Values. This river flows through many towns and villages along the entire course, but the main anthropogenic influence comes from Banja Luka, one of the largest cities in Bosnia and Herzegovina.The aim of this research was to characterise extractable organic matter of sediments from the Vrbas River in the city area of Banja Luka. Six samples were collected at locations which were selected based on the vicinity of potential sources of anthropogenic pollution: 1 and 3 – sites near bridge and frequent traffic, 2 – city’s promenade, 6 – site in the vicinity of the thermal power plant, 7 – site close to Banja Luka Brewery and the bridge on frequent road, and 8 – site close to the food industry “Vitaminka”. Extractable organic matter was isolated with dichloromethane/ methanol mixture using a Soxhlet apparatus. Hydrocarbons were isolated from the extracts using a column chromatography and analyzed by gas chromatography – mass spectrometry (GC-MS). Detailed analysis of n-alkanes (m/z 71), diterpanes (m/z 123), hopanes (m/z 191) and steranes (m/z 217) was done. The individual peaks were identified by comparison with literature data [1] and based on their mass spectra (library: NIST11). Among saturated hydrocarbons diterpane, 16α(H)phyllocladane is the most dominant component in almost all samples (Fig.1). The exception is a sample 7. This diterpane is followed by n-alkanes with a predominance of higher odd homologues. It indicates predominately native organic matter of Vrbas river sediments, originated mostly from terrestrial plants. That was noticed the predominant presence of native organic material in noticed in samples 2, 3, 6, while the presence of oil type pollutants was confirmed in other samples (1, 7, 8), which are near the bridge and frequent traffic roads. Fig 1. Total ion current (TIC) of saturated fraction. The previous study regarding the contents distribution of heavy metals in these sediments showed that most contaminated samples are at sampling points 2 and 6 [2]. That is not the case with oil contamination pointing to probably different sources of anthropogenic pollution

The use of biological markers in the determination of the origin and type of organic matter in the sediments of the Tisza River

The objective of this study was to determine the origin and type of organic matter (OM) in recent sediments of the Tisza River, along a distance of 153 km through the territory of Serbia. For this purpose, group organic-geo-chemical parameters and biomarker compositions were used. All samples contained approximately same amount of OM, which was deposited under uniform, slightly reducing conditions. Based on the distribution of n-alkanes, the origin and type of OM could not be precisely estimated. However, the n-alkane patterns suggest the presence of immature singenetic organic matter of terrestrial origin. The distributions of terpanes and steranes and the values of the corresponding maturity parameters indicate that the Tisza River sediments, apart from immature singenetic organic matter, contain oil pollutants of anthropogenic origin. The identical compositions of these biomarkers in all samples confirmed that the recent sediments of the Tisza River, from Kanjiza Town to the confluence into the Danube River, contain the same type of oil pollutants. Based on the compositions of terpanes and steranes and the values of the biomarker parameters in Tisza sediments, it is supposed that the oil pollution generally could be related to heavy fuel oil from tankers, due to intense river transport and, to lower extent, to crude oils from the Elemir and Rusanda oil fields

Разработка технологии изготовления детали «Плоская пружина»

Плоская пружина – деталь, входящая в сборку узла динамометрической оправки, предназначенной для алмазного выглаживания. Цель работы: анализ и совершенствование технологического процесса изготовления детали "Плоская пружина"; назначение режимов резания и инструмента для обработки детали; проектирование приспособления для изготовления детали "Плоская пружина". Были рассчитаны технологические размеры; даны рекомендации по выбору режимов резания, инструмента и оборудования. При усовершенствовании технологического процесса было выполнено: выбраны базы и схемы установки; разработана маршрутная и операционная технология; определены технологические допуски, припуски на операционные размеры; выбрано нужное оборудование с ЧПУ, приспособления и инструмент для обработки детали.Flat spring–part included in assembly diamond chuck for diamond smoothing. Objective: analysis and improvement of the technological process of manufacturing parts "Flat Spring"; the appointment of cutting modes and tools for machining; design tools for the manufacture of parts "flat spring". The technological dimensions were calculated; are given recommendations on the choice of cutting modes, tools and equipment. With the improvement of the technological process it was performed: the bases and installation diagrams were selected; route and operational technology developed; defined technological tolerances allowances for operating dimensions; selected CNC equipment, fixtures and tools for machining the part; calculated cutting conditions and basic standards

The Response of Badland Materials from Spain with Different Mineralogical Content on Seasonal Changes

Badlands are areas with limited vegetation, reduced or no human activity, and a great variety of geomorphic processes [1]. Badland materials have a different responsetothe same environmental conditions, because of differences in their mineralogical and physico-chemical characteristics. Many studies show that smectite-poorsediments are more resistant to different weathering treatments of freezing, thawing, wetting, and drying,than smectite-rich materials [2,3].In this paper, three unweathered samples of badlands from Spain were analyzed with the aim of monitoring, but also comparing physico-chemical changes caused by simulations of changes in climatic conditions. Selectedsediment samples havedifferent compositions. Besides quartz and calcite, the first sampleis composed of smectite and gypsum (3 UW), the second of smectite (4 UW), while the third sample is composed of neither smectite nor gypsum (5 UW). The experiment setup was designed in the way that each sample had three sub-samples, a sample for simulation of rain, snow, and a control sample (Figure 1). Sample_rain was treated with a rain intensity of ~850 ml/h for 10 minutes (~140 ml), while sample_snow was treated with crushed ice (~150 g). After precipitation simulations snow were put samples were placed in a climate chamber at - 3 °C together with a control sample. This was repeated for 15 cycles. Every cycle was documented with photographs. The leached solution was collected and its volume, pH, electrical conductivity (EC), and ion concentrations were measured. The second part of the experiment was based on exposing the samples after wetting to higher temperatures, 50 ° C. It was done in 8 cycles. FESEM and BET analyzes were performed for each sample before and after the experiments.The 3 UW samples had significantly different leachate pH and EC, while the leachate volume was similar for all samples during the experiment. Sulphate ions were leached in the highest concentrations during the whole experiment from the sample with both smectite and gypsum present. The sample with smectite has shown the highest disintegration of the structure, especially after the simulation of snow. The sample with smectite and gypsum has shown a lower degree of degradation than sample 3 UW due to the content of gypsum which increases the weathering resistance of the material. Sample 5 UW has shown the lowest degradation of the structure along with the weathering cycles. This study has proven that both mineralogical and physico-chemical properties of sediments are important for predicting their response to variable climate factors