Composition Of Bitumen Research Articles

Features of the elemental, structural-group, and microelement composition of asphaltenes from natural bitumens of the Permian deposits of Tatarstan

Using a complex of physical and chemical methods studied features of the elemental, structural-group, and microelement composition of natural bitumen asphaltenes extracted from bituminous rocks of Tatarstan’s Permian deposits. It is an investigated interconnection of value changes of spectral parameters (of aromaticity, oxidation, and aliphatic) characterizing of structural-group composition of original bitumen and asphaltenes. The features of the microelement composition of asphaltenes of bitumen of various types were also revealed.

Features of the change in the composition heavy oils of various types and solid asphaltite in the hydrothermal-catalytic conditions

The paper reveals the distinctive features of the change in the composition heavy oils of various types and of natural bitumen - asphaltite from the sandstones of the Permian sediments of the Spiridonovsky field in the territory of Tatarstan, in model experiments at a temperature of 250°C, characteristic for steam-thermal impact on the formation, and the pressure in the system of not more than 2 MPa. The choice of low pressure is due to the fact that bituminous rocks in the Permian sediments occur at relatively shallow depths in the near-surface deposits of the sedimentary strata, which necessitates the development of special technologies for their extraction. The experiments used natural iron oxide - hematite. As a part of the products of asphaltite conversion under the influence of hydrothermal-catalytic factors, the content of hydrocarbons almost 4-fold, the content of alcohol-benzene resins and asphaltenes decreases. The content of benzene resins increases somewhat. The composition of asphaltite proved to be less stable than of heavy oils from age-old sediments, apparently due to special conditions for the formation of its composition in natural conditions under the influence of secondary low-temperature biochemical processes that led to the accumulation of thermally unstable resinous-asphaltene components. Compared with the original asphaltite, in the products of the experiment, the content of alkanes of composition C10-C30 substantially increases with an obvious predominance of homologues with an even number of carbon atoms in the molecule. The product is characterized by a lesser degree of aromaticity and content of sulfoxide groups. The results of the studies showed the possibility of upgrading the composition of solid bitumen - asphaltite in in situ conversion by diluting its composition with lighter newly formed hydrocarbons, due to the destruction of its high molecular weight components.

Methods of step extraction of rocks of high-carbon formations for the study of the component distribution of bitumen and variability of their basic geochemical parameters

The article describes organic-rich rocks sequential extraction method for the bitumen composition difference. The method step-by-step extracts bitumen first from open and then from closed pores using three organic solvents with increasing polarity. The released bitumen differs in malthens/asphaltenes ratio, the distribution of n-alkanes, the content of terpanes and steranes, and, thus, the values of the biomarker parameters. These parameters show difference in the degree of organic matter thermal maturity, which is relates to different types of rock pore space. At the same time different parameters show different maturity ratio between bitumen from open and closed pores. Changes in the composition of bitumen allow to estimate the migration of hydrocarbon compounds through the well, to investigate the effect of sedimentation conditions on the pore space and the distribution of bitumen. The results show that investigation of bitumen received by one-step extraction from powder can lead to incorrect interpret of obtained results.

Numerical investigation of rubber swelling in bitumen

Crumb rubber modified bitumen (CRMB) has been utilized in the asphalt paving industry for decades due to its various benefits. The main mechanisms of bitumen-crumb rubber interaction include rubber particle swelling and chemical degradation. Crumb rubber modifier (CRM) swelling plays a dominant role in controlling the property development of CRMB during the traditional interaction process. To have a better understanding of the swelling behavior of rubber in bitumen, this study developed a finite element model capable to simulate the multiphysics swelling phenomenon consisting of mass diffusion and volume expansion. The effects of various factors including material characteristics and process conditions on the rubber swelling in bitumen were investigated. The results indicate that the coupled diffusion-expansion model can predict the swelling behavior of rubber in bitumen. A good correlation between the simulation results and the previously reported evidences was observed. The effects of bitumen composition, rubber type and size, interaction temperature and time on swelling were successfully demonstrated by using the developed model with dedicated input parameters. With this study as a foundation, the estimated rubber swelling behavior in bitumen can be implemented into suitable micromechanical models to predict the viscoelastic properties of CRMB and consequently to optimize the design and process of bitumen-rubber blends.

Rheological Characteristics Evaluation of Bitumen Composites Containing Rock Asphalt and Diatomite

Previous studies have showed that rock asphalt (RA) or diatomite were used to modify the petroleum bitumen. This paper presents the findings from a study conducted to evaluate the potential impact of RA and diatomite on the rheological characteristics of bitumen composites. RA and diatomite with three different dosages were added into the petroleum bitumen: 18% RA, 13% RA+7% diatomite, and 16% RA+9% diatomite by weight. The rheological characteristics of the RA and diatomite modified bitumens were evaluated in this study. The tests conducted included temperature sweep and frequency sweep tests with a dynamic shear rheometer (DSR), a Brookfield rotation viscosity test, and a scanning electron microscope test. The research showed that the addition of RA and diatomite to petroleum bitumen considerably increased the apparent viscosity, dynamic shear modulus, and rutting resistance in bitumen specimens. However, the DSR test indicated a slight reduction in the fatigue performance of composites made of RA and diatomite modified bitumens. Overall, RA and diatomite are good modifiers for petroleum bitumen for a performance improvement.

A Study of the Products of Supercritical Fluid Extraction of Coals from the Chadan Deposit by Thermogravimetry and IR Spectroscopy

The thermal properties of the solid products of supercritical fluid extraction of coal from the Chadan deposit in benzene and the composition of bitumens separated in different temperature ranges (to 120, 120–200, 200–285, and 285–400°C) were studied. In contrast to the original coal, the thermal destruction of insoluble solid coal residue from extraction began at a higher temperature, and it was accompanied by a lower yield of volatiles. A comparative analysis of the characteristic parameters of the IR spectra and chromatograms showed changes in the composition of bitumen as a function of the extraction temperature: at low temperatures, oil components were extracted from coal, and the concentrations of tars and asphaltenes increased with temperature.

Characterization of Bitumen Binders on the Basis of Their Thermo-Viscous Properties

Abstract Bitumen is one of the basic building materials that is mainly used in road construction. Nowadays, we can observe increased requirements for the quality of bituminous binders, which are due to increased traffic loads, changing climate conditions, and decreasing crude oil stocks. Besides “traditional” (empirical) tests (softening point, penetration), new types of tests have been developed that can better describe the quality and behavior of bitumen binders. Their composition can also be a significant part of the properties themselves. Therefore, the elemental and group composition of bitumen must also be observed. The use of the viscosity temperature susceptibility (VTS) test appears to be well suited to evaluate the properties of bitumen binders. The VTS parameter is directly dependent on the viscosity of bitumen, but it is necessary to say that VTS can be significantly affected by the composition of the bitumen. The paper is focused on determining the dependencies between the VTS and the bitumen’s composition, respectively, to find out how the composition influences the VTS.

Bitumen and Bitumen Modification: A Review on Latest Advances

This synthesis explores the state-of-the-knowledge and state-of-the-practice regarding the latest updates on polymer-modified bitumens (PmBs). The information in this study was gathered from a thorough review of the latest papers in the literatures related to modified bituminous materials, technologies, and advances. For this purpose, the paper is presented in two principle sections. In the first part, the bitumen itself is investigated in terms of chemical structure and microstructural systems. In the second part, the paper focuses on bitumen modification from different aspects for assessing the effectiveness of the introduced additives and polymers for enhancing the engineering properties of bitumen in both paving and industrial applications. In conclusion, the knowledge obtained in this study has revealed the importance of the chemical composition of base bitumen for its modification. It can be declared that while some polymers/additives can improve one or some aspects of neat bitumen properties, they can lead to compatibility problems in storage and production. In this respect, several studies showed the effectiveness of waxes for improving the compatibility of polymers with bitumen in addition to some benefits regarding warm mix asphalt (WMA) production.

Degradative Effect of I.R Radiations on the Constituents of Bitumen

Sample of natural bitumen were taken from bitumen well in Agbabu town in Odigbo Local Government of Ondo State. These samples were separately irradiated with infrared radiations for a period of seven hours. Part of the sample was withdrawn at interval of One, Three and Seven hours. The withdrawn sample was later separated into maltene and asphaltene fractions. The maltene fraction was further separated into saturated, aromatic and polar fraction. The saturated and aromatic fractions were subjected to gas chromatography analysis. The Saturated and aromatic profiles of the bitumen were found to vary with the period of irradiation. The Chemical composition of both the saturated and aromatic compounds in the bitumen decreased with the period of irradiation. Thus, decrease in the chemical composition of bitumen as a result of irradiation cause aging of bitumen. Therefore, I.R radiations were found to have a degradative effect on the composition of bitumen.

Analysis of influence of bitumen composition on the properties represented by empirical and viscosity test

Abstract Bitumen are one of the products in oil processing. The properties of bitumen are influenced by the source of oil itself and by the technological process of oil processing. Most European refineries, of course, are processing for reasons of the resale of petroleum products, especially petroleum suitable for the recovery of light and middle fractions. Therefore, light petroleums are required, with low yields of heavy fractions which are highly economically and in dispositions efficient for processors on the petroleum market. From the perspective of the rafinery the content and the ratio of asphaltenes and maltenes as essential components of bitumen become less important, however, this can significantly impact on future properties of the bituminous binder. The basic tests as penetration and softening point are dedicated to evaluate the bitumen properties and classify the bitumen. These tests are currently insufficient and therefore new test methods and procedures for bitumen characterization are developed. The main theme of the performance-based approach to bitumen binders’ properties assessment is the evaluation of properties from the pavement performance point of view as permanent deformation, fatigue and frost cracking. The evaluation of changes of bitumen properties during the production and paving process of the asphalt mixture is also important. The study is focused on investigating the viscous-temperature behavior and fundamental properties represented by the penetration and the softening point of the samples of paving grade bitumen 50/70 and polymer modified bitumen PMB 45/80-75. The composition of the bitumen was determined by the SARA analysis and organic elemental analysis. The paper points out how the “traditional” tests as softening point, penetration, and viscosity are affected by the composition of bitumen and how the composition of bitumen changes the basic properties of bitumen.

Research of influence of adhesive additives on physical and chemical properties of road bitumens

To increase the adhesion strength (wetting ability) of bitumen, and, consequently, reduce the likelihood of premature occurrence of defects formed on asphalt concrete coatings, it is necessary to use various kinds of surfactants that increase the adhesion ability of bitumen. Adhesive additives to road bitumens increase the mobility of the organic binder, help reduce the number of uncoated grains of mineral material, which facilitates the compaction of asphalt concrete mix. One of the problems of durability of asphalt concrete pavements is the lack of strong adhesion of the bitumen film to the surface of the mineral material. To increase this strength, various adhesive additives are used, which affect not only the adhesive properties of bitumen, but also its physical and chemical properties. The main task of the work is aimed at solving the issues of the influence of adhesive additives on the physicochemical properties of organic binders used in road construction. The quality assessment of the modified bitumen was carried out according to GOST 22245-90, which, at present, is guided by the selection of the composition of the asphalt concrete mixture. As a result of the study, effective adhesive additives were identified that contribute to the minimal change in the physicochemical properties of viscous road bitumen and possess thermal stability under prolonged exposure to elevated temperatures. Studies have shown that almost all adhesive additives not only improve the adhesive properties of organic binders to mineral materials, but also can alter and even worsen the physicochemical properties of the original organic binder, which can adversely affect the properties of asphalt concrete. The study used the original bitumen from only one manufacturer and the negative effect of adhesive additives may be due to the incompatible chemical composition of the adhesive additive with the group composition of bitumen and the mineralogical composition of the mineral material.

Effect of Aging on Chemical and Rheological Properties of Bitumen.

Engineering performance of asphalt pavement highly depends on the properties of bitumen, the bonding material to glue aggregates and fillers together. During the service period, bitumen is exposed to sunlight, oxygen and vehicle loading which in turn leads to aging and degradation. A comprehensive understanding of the aging mechanism of bitumen is of critical importance to enhance the durability of asphalt pavement. This study aims to determine the relations between micro-mechanics, chemical composition, and macro-mechanical behavior of aged bitumen. To this end, the effect of aging on micro-mechanics, chemical functional groups, and rheological properties of bitumen were evaluated by atomic force microscope, Fourier transform infrared spectroscopy and dynamic shear rheometer tests, respectively. Results indicated that aging obviously increased the micro-surface roughness of bitumen. A more discrete distribution of micromechanics on bitumen micro-surface was noticed and its elastic behavior became more significant. Aging also resulted in raised content of carbonyl, sulfoxide, and aromatic ring functional groups. In terms of rheological behavior, the storage modulus of bitumen apparently increased after aging due to the transformation of viscous fractions to elastic fractions, making it stiffer and less viscous. By correlation analysis, it is noted that the bitumen rheological behavior was closely related to its micro-mechanics.

Comparative toxicity of two diluted bitumens to developing yellow perch (Perca flavescens)

Increasing demand for diluted bitumen (dilbit) has led to the development of the oil sands industry and the expansion of transcontinental pipelines. Dilbit is an unresolved complex mixture with variable diluent and bitumen composition. Thus, it is important to understand the effects of the two most transported dilbits in Canada, Access Western Blend (AWB) and Cold Lake Blend (CLB) on a North America native and freshwater fish species, the yellow perch (Perca flavescens). Fertilized embryos were exposed to both dilbits for 16 days, from <24 h post-fertilization until hatch. The treatment regime was a static daily renewal of water accommodated fractions (WAF) and chemically-enhanced water accommodated fractions (CEWAF) at concentrations ranging from 0.01 to 21.3 μg/L of total polycyclic aromatic compounds (TPACs). Hatched embryos were assessed for malformations and changes in the expression of genes associated with phase I and II detoxification and oxidative stress. The prevalence of developmental malformations increased significantly at the highest concentrations of all treatments, with WAF treatments yielding a higher prevalence than CEWAF. The EC50s for AWB and CLB WAF and CEWAF solutions ranged from 9.8 to 24 μg/L TPACs, with the CEWAF of AWB being the least toxic. Relative mRNA levels of cyp1a showed induction by up to 18-fold in WAF and 50-fold in CEWAF treatments at similar concentrations of measured dilbit in solution. Complementary DNA methylation analysis was assessed and fish embryos exposed to AWB CEWAF and CLB WAF showed decreased DNA methylation profiles with increasing exposure to dilbit, suggesting that global gene expression is increasing in these treatments. With recent approvals of pipelines in North America, these data will support site-specific risk assessments and monitoring of Canadian ecosystems should a pipeline spill occur.

Heterogeneity of free and occluded bitumen in a natural maturity sequence from Oligocene Lake Enspel

Sedimentation in Oligocene Lake Enspel was rapidly terminated by a basaltic lava flow. This introduced a preservational barrier while imparting a ‘natural flash pyrolysis’, during which the organic matter in underlying stratigraphic units was subjected to rapid thermal maturation resulting in hydrocarbon generation. Samples from these strata exhibit a steep maturity gradient (0.25–1.07% optical vitrinite reflectance, or RO) over uniform organofacies. This offers the opportunity to investigate bitumen generation during rapid thermal maturation mechanistically, in particular the nature of Bitumen 2—occluded bitumen, which is only recoverable after the digestion of the mineral matrix and was frequently dismissed as an artifact of incomplete extraction. Elaborate sequential extraction of the contact metamorphic sequence of oil shales at Enspel revealed systematic changes in bitumen composition. These trend progressively towards those of occluded bitumen, which exhibits a systematically elevated thermal maturity, a higher degree of catalytic biomarker-rearrangement and the conspicuous absence of molecular signatures from vascular plants that are present in the free bitumen. One plausible explanation involves a contribution of allochthonous clay-adsorbed organic matter to Bitumen 2. This could represent a mixture of older reworked bitumen and an early-diagenetic snapshot of clay adsorbed organic matter. Alternatively, a close association of early-generated bitumen with clay minerals may have led to enhanced isomerization and catalytically influenced ‘uniformization’ of alkane signatures. Deviations from the expected relationships between various thermal maturity parameters suggest variable dependence on the time-pressure-temperature pathway (i.e. metamorphic facies). The maturation of organic matter likely behaves differently under a contact metamorphic regime or during rapid subsidence and exhumation, as compared to slow maturation during regional subsidence. Our data also suggest that geologically brief shallow intrusive or extrusive magmatism might not be as destructive to the sedimentary hydrocarbon inventory as hitherto thought. This study draws attention to the small-scale compositional heterogeneity of bitumen that can be studied using sequential extraction methods. More importantly, it suggests that occluded bitumen could potentially harbor information on organic matter that pre-dates in situ primary productivity and may be derived from allochthonous biomass and detrital input.

Geological controls on the heterogeneous hydrocarbon compositions of the biodegraded Grosmont Formation bitumen, Western Canada Sedimentary Basin

The hydrocarbon composition of the Grosmont Formation bitumen was investigated in 51 core samples by gas chromatography–mass spectrometry (GC–MS). The bitumen composition is highly variable and is heavily to severely biodegraded. Molecular ratios based on biodegradation-resistant compounds are highly uniform laterally and vertically, even across shale barriers indicating the bitumens are genetically related. Biodegradation-resistant biomarker maturity parameters suggests the bitumen was likely sourced during the early oil window stage of petroleum generation. Biomarkers responding to biodegradation display strong lateral and vertical variations in composition with geochemical profiles based on concentration data, displaying dramatic offsets when shales are present indicating the reservoir units are compartmentalised. Considering the relationship between 25-norhopanes and hopanes, the hydrocarbon composition data indicate progressive hopane degradation, both with concomitant formation of 25-norhopanes and hopane degradation without the formation of 25-norhopanes. In wells 07-08-085-18W4 and 10-12-093-24W4, the degradation of hopanes occurs in Upper Grosmont unit 3 (UG3) without the formation of 25-norhopanes (unless 25-norhopanes have been synchronously consumed), whereas in unit UG2, hopane degradation occurs with the concomitant formation of the 25-norhopanes. Therefore, the shale compartmentalizes the reservoir creating two isolated environments whereby the biogeochemical setting contributing to 25-norhopane formation is found in the UG2 unit, whereas it is absent or inactive in unit UG3. The degradation of the 22R epimer prior to the 22S epimer in the C31–C33 17α-hopanes was recognized in well 16-05-088-19W4, which indicates that the consortia of microbes more readily biodegraded the epimer having the biological conformation.

Molecular markers, carbon isotopes, and rare earth elements of highly mature reservoir pyrobitumens from Sichuan Basin, southwestern China: Implications for PreCambrian-Lower Cambrian petroleum systems

The Moxi–Gaoshiti Bulge of the Sichuan Basin in southwestern China is unique because it provides insights into the geochemistry of Lower Cambrian reservoir bitumens and their geological significance for paleo-oil reservoirs. Analyses of biomarkers, carbon isotopes, trace elements (TE) and rare earth elements (REE) were conducted on reservoir bitumens and the associated source rocks to constrain sedimentary environments and bitumen/paleo-oil sources. Based on biomarkers, carbon isotopes, TE ratios and REE distribution patterns, both of the Cambrian Qiongzhisi (Є1q) and Sinian Dengying (Z2dn) source rocks can be hydrocarbon sources for the Cambrian Longwangmiao (Є1l) bitumens in the MG Bulge (Lower Cambrian Doushantuo Formation not discussed here). Abundant n-alkanes relative to isoprenoids, significant C21 and C22 steranes, predominance of dibenzothiophene (DBT), and low ratios of biomarkers, such as Pr/Ph, DBT/P, C22TT/C21TT and C35H(22S)/C34 H(22S) indicated that the source rock was characterized as shale from an overall highly reducing marine depositional environment. The average δ13C values from the compositions of the solid bitumens show an abnormal order: saturate hydrocarbons < asphaltenes < N-S-O compounds < aromatic hydrocarbons, suggesting that high temperature might affect the normal fractionation among different organic matter fractions. The reservoir bitumens are enriched in Mo, Tl, Pb and Ba, strongly depleted in Bi Compared to PAAS, and mostly well correlated in the REE distribution patterns. In the primary migration pathways suggested by the DBT concentration, the parameters ∑REE and Zr/Cu show an overall increase, and the ratios V/Ni, Ni/Co, V/Zr and V/Cr have decreasing trends. The comprehensive analyses of molecular biomarkers, carbon isotopes, TE and REE in pyrobitumens of the highly mature reservoirs in this study suggest a potential means to study paleo-oil reservoirs, and can thus provide valuable information for deep oil and gas exploration in Precambrian – Lower Cambrian petroleum systems.

Study of crack resistance of asphalt concrete pavements of the streets of the city of Bryansk and roads of the Bryansk region

Asphalt concrete is the main type of coating the streets of the city of Bryansk and other cities of the Bryansk region, as well as roads outside settlements. A survey of the condition of asphalt concrete pavement of the streets of Bryansk and some parts of roads of other cities of the Bryansk region (streets of Surazh, Klintsy, Unecha, etc.) showed that in many areas there are surface destruction in the form of cracks: transverse, longitudinal and «grid». The presence of a crack in the coating of the road-reducing the load – bearing capacity of the road structure at the place of its formation. The crack resistance of asphalt concrete decreases during the operation of the coating due to a number of reasons: deterioration of the properties and structure of asphalt concrete under the influence of internal and external factors (water, freezing-thawing, air oxygen, ultraviolet and infrared irradiation, the nature and degree of interaction of bitumen with mineral material, the structure and composition of bitumen, etc.), low-temperature stretching, aging of the binder, etc. The authors of these studies set the task to check the quality of the properties of bitumen BND 60/90 and BND 90/130 with the introduction of polymer additives, carbon black, etc., as well as asphalt concrete mixtures with the introduction of polystyrene and polyurethane foam and other additives in the construction of road surfaces in hot summer climatic conditions to increase the crack resistance of asphalt concrete coatings. The paper presents an analysis of the main parameters of transverse cracks in the city of Bryansk on the streets: Fokina, Sovietskaja, Gorbatova, Krahmaleva, as well as road surfaces of the Bryansk region.

NMR-Spectroscopy Determination of Fragmentary Composition of Bitumen and its Components

This paper represents and discusses the results of quantitative determination for fragmentary composition of road bitumen of grade BND 100/130 and its components (asphaltenes, resins and oils) by NMR spectroscopy method. Group chemical composition of the bitumen has been determined by adsorption chromatography method. It has been identified that the bitumen and its components consist only of aromatic and aliphatic protons, which account for 2.4‒10.2% and 9.8‒97.6% respectively. Availability of olefinic elements in them has not been identified. The most part (79‒81%) of nuclei of carbon atoms relates to quaternary carbon atoms of saturated compounds. Primary carbon atoms at methylene group (CH2) are contained in the least quantity: bitumen ‒ 1.32%; asphaltenes – 0.6%; resins – 3.24% and oils – 2.11%. Primary carbon atoms, linked with CH-group or aromatic nucleus, occupy an intermediate position and are contained in the quantity of 17‒20%.

Application of infrared spectroscopy and partial least-squares for modeling the correlation of bitumen dynamic shear rheological with temperature

ABSTRACTThis paper reported a method for determining the correlation of the physical properties and the chemical composition of bitumen. The double-log model of dynamic shear modulus with temperature was performed for linearization treatment to obtained the constants, which were served as the independent variables using in partial least-squares(PLS) regression. In addition, infrared spectra were processed by data pretreatment methods and served as dependent variables in PLS. The regression vector b of PLS made possible the observation of the spectral regions contributing in the modeling, which provided a basis for research of the correlation between physical properties and chemical composition of bitumen.

Effect of blending conditions on nano-clay bitumen nanocomposite properties

Nanoclay/bitumen nanocomposites have been prepared using a commercial organically modified nanoclay (Nanomer), and two different penetration grade bitumens under a range of different blending conditions. Simple paddle stirring and high-shear mixing for different times at different shear speeds were investigated in order to determine whether expensive and time-consuming blending was necessary to achieve significant changes in the properties of the bitumen composites. Longer blending times and/or higher shearing speeds resulted in increased dispersion and exfoliation of the Nanomer particles, but this was not necessarily beneficial to the physico-chemical properties of the final material. Rheological analyses showed insignificant differences in properties between the samples blended for different times and speeds of shear mixing. Simple paddle mixing was sufficient to disperse the Nanomer to generate nanocomposites with improved physical properties. Dispersion of Nanomer into the softer of the two bitumen grades caused larger apparent changes than blending into the stiffer grade. These results suggest that the use of simple, low-cost blending techniques should be possible to manufacture effective clay-bitumen nanocomposites.