Narrow Fractions Research Articles

Performance evaluation of manisa-soma derekoy coal washing plant with density tracers

ABSTRACT Performance evaluation of coal-washing plants is a laborious and long-term process. In the traditional performance evaluation method, samples taken from the plant’s feed and products are separated into narrow grain size fractions and subjected to heavy liquid tests. This method is difficult, time-consuming, and requires weeks of experimental work. However, a new, more efficient method has emerged with the introduction of density monitors. A performance curve can be generated in just a few hours, allowing for the instantaneous measurement of the coal-washing plant’s performance. This represents a significant advancement in our field. Performance evaluation studies were carried out using 32 mm density monitors to determine the performance of three product cyclones in the Derekoy Coal Washery operating under the Aegean Lignite Operation Directorate of TKI. In the study conducted with 64 mm, 32 mm, and 16 mm density monitors in Dereköy Sludge, the separation densities in the 1st and 2nd heavy medium drums at 64 mm dimensions were 1.533 and 1.616 g/cm3, respectively, and the Ep values were 0.035 and 0.060, respectively. In 32 mm sized 1st and 2st heavy medium cyclones, the separation densities were 1.745 and 1.795 g/cm3, and Ep values were 0.013 and 0.038, respectively. In 16 mm sizes, separation densities in the 1st and 2st heavy medium cyclones were 1.745 and 1.793 g/cm3, respectively, and Ep values were 0.014 and 0.037, respectively.

Anchored Ru nanoclusters strategy enhances hydrogen spillover effect for high-efficiency hydrogen storage

Enhancing the hydrogen spillover effect of catalysts is an effective method for optimizing hydrogen storage reactions. In this study, we report a catalyst consisting of Ru nanoclusters (1.2–2.7 nm) anchored on nitrogen-doped carbon (NC) that are highly dispersed on an Al2O3 substrate. Both experimental and density functional theory-based calculations indicate that these constrained, highly dispersed ultrafine nanoclusters significantly improve the intrinsic catalytic activity of Ru and reduce the reaction barriers. Moreover, the electron transfer between NC and Ru clusters increases the adsorption inertness of Ru with hydrogen, enhances hydrogen desorption, and promotes hydrogen spillover, synergistically improving the activity of catalytic hydrogen storage. Notably, the aromatic compounds in the ethylene tar narrow fraction were effectively converted at a low temperature of 80 °C, and the total cycloalkanes yield reached 99.04 %. The hydrogen storage capacity can be about 5.70 wt%. Liquid Organic Hydrogen Carriers model compounds were fully hydrogenated at temperatures no higher than 70 °C with low Ru loading (2 wt%). This work provides a potential utilization strategy of ethylene tar narrow fraction as hydrogen carriers based on its hydrogenation over the highly active and stable Ru nanocluster catalysts.

Composition of gasolinefractions of Kumkol oil and improvement of theiroperational properties

The physicochemical properties of gasoline fractions of paraffinic oil from the Kumkol field have been investigated and the distinctive features of the individual hydrocarbon composition of the straight-run gasoline fraction and catalytic reforming gasoline have been established. The wide straight-run gasoline fraction (62-180°C) of Kumkol oil was subjected to preliminary hydrotreating at an industrial unit that is part of the catalytic reforming unit using S-12T and GO70 catalysts at a process temperature of 315 – 343°C, a pressure in the reactor of 21 – 27 atm, a volume feed rate of 6.4 – 9.4 h-1, with the circulation of HCG (Hydrogen-containing gas) «on the duct». Conditions under which catalytic reforming was carried out: temperature in the reaction zone – 470 ÷ 500°C, pressure – 28 kgf/cm2 , volumetric feed rate of raw materials – 1.5 h-1, gas circulation – 5.9 mol H2 / mol of raw materials. It has been established that in the process of reforming, as a result of isomerization of n-paraffins and dehydrogenation of cylanes, isoparaffin and aromatic hydrocarbons are intensively formed in the composition of reformant, and thereby the octane number of reforming gasoline is sharply increased. Gasoline obtained in the process of catalytic reforming from a narrow fraction of Kuikol oil meets the requirements for commercial, high-octane grades of motor fuel in all quality indicators. A significant synergistic effect has been established with the combined action of a two-component mixture compared to that for individual additives: a small concentration of the additive Hightech (manganese-containing) 18 mg/l and oxygen-containing AHA (ash-free high-octane additive) increases the octane number M.M. (motor method) by 3.3 points and according to R.M. (research method) by 5.3 points, and when introducing the additive Hitech 18 mg/l in a mixture with N-methylaniline, the increase in the O.N. (octane number) for M.M. was 4.4 units, and for R.M. (research method) – 6.

Hydrogen storage with a naphthenic liquid organic hydrogen carrier (LOHC) obtained from coal tar

A method for producing a liquid organic hydrogen carrier (LOHC) from coal tar is proposed. The carrier, a narrow fraction (T10%/T90% = 199/224 °C) with a naphthenic content of ≈99.9 wt%, was obtained through deep hydrogenation of the corresponding fraction of coal tar recovered by vacuum distillation. As a result of hydrogenation, deep purification from sulfur compounds (<5 ppm) was achieved. The composition of the produced carrier was characterized in detail by GCxGC/MS to identify the main components. Further data processing allowed for the calculation of the theoretic hydrogen capacity (6.3 wt %) and hydrogen mass fraction (13.16 wt %). Dehydrogenation in a batch reactor produced a dehydrogenated form of the carrier with a dehydrogenation degree of about ≈82–85%. The main physical properties (density, boiling range, viscosity, and flash/freezing/pour points) were described. The resulting carrier was dehydrogenated in a flow reactor using a Pt/C catalyst, demonstrating stable operation for 108 h. Moreover, the LOHC derived from coal tar exhibited stability in its properties across three consecutive hydrogenation-dehydrogenation cycles conducted over a Pt/C catalyst at 360–370 °C.

Optically active components of oil from the deepwater Gunashli field

The article presents the results of study of deep-water Gunashli oil’s optically active components. Oil is separated into 50 oC fractions, after studying the physicochemical properties of the resulting fractions, they are dearomatized by liquid chromatographic adsorption, as well as polar and non-polar solvents. The physicochemical properties, optical activity and chiroptic properties were studied, as well as the structural composition of the obtained naphthene-paraffin hydrocarbons was studied by IR spectroscopic analysis. The highest properties of optical activity are observed in naphthene-paraffin hydrocarbons, which boil away in the temperature range of 400–450 oC. The obtained results are very important in the selection of petroleum components, obtaining their narrow fractions, as well as the identification or isolation of optically active substances.

Application of Intercriteria and Regression Analyses and Artificial Neural Network to Investigate the Relation of Crude Oil Assay Data to Oil Compatibility

The compatibility of constituents making up a petroleum fluid has been recognized as an important factor for trouble-free operations in the petroleum industry. The fouling of equipment and desalting efficiency deteriorations are the results of dealing with incompatible oils. A great number of studies dedicated to oil compatibility have appeared over the years to address this important issue. The full analysis of examined petroleum fluids has not been juxtaposed yet with the compatibility characteristics in published research that could provide an insight into the reasons for the different values of colloidal stability indices. That was the reason for us investigating 48 crude oil samples pertaining to extra light, light, medium, heavy, and extra heavy petroleum crudes, which were examined for their colloidal stability by measuring solvent power and critical solvent power utilizing the n-heptane dilution test performed by using centrifuge. The solubility power of the investigated crude oils varied between 12.5 and 74.7, while the critical solubility power fluctuated between 3.3 and 37.3. True boiling point (TBP) analysis, high-temperature simulation distillation, SARA analysis, viscosity, density and sulfur distribution of narrow petroleum fractions, and vacuum residue characterization (SARA, density, Conradson carbon, asphaltene density) of the investigated oils were performed. All the experimentally determined data in this research were evaluated by intercriteria and regression analyses. Regression and artificial neural network models were developed predicting the critical solubility power with correlation coefficients R of 0.80 and 0.799, respectively.

Визначення крупності продуктів подрібнення

Mathematical approaches to particle size determination in closed grinding cycles are considered. The features of average particle size calculation for different fractions with account for the grinding kinetics are shown. Particle size calculation algorithms for the entire fraction range are proposed. Particular attention is paid to output determination for fractions of arbitrarily small particles. A particle size determination method based on a lognormal distribution function is shown. In choosing the mathematical approach, the process requirements are taken into account. The basis of in-flow noncontact particle size control is the acoustic monitoring of the process and the established relationships between the particle size and the acoustic characteristics. The signal amplitude during material transportation in the energy carrier flow and jet grinding was found as a function of the particle size and grinding conditions. In order to determine the fractional composition of a mixture, the frequency characteristics of acoustic signals and their variation during the transportation of narrow fractions and mixtures were considered. The analysis of the amplitude-frequency characteristics of acoustic signals during the compressed-air transportation of narrow fractions in the jet mill channels confirmed the presence of signals with frequencies characteristic for each fraction. These frequencies were experimentally related to the particle size of a fraction in a mixture. These studies form a basis for a noncontact method of determining the particle size distribution of a material in an air flow, in particular in jet grinding. The results may be used for engineering and technological calculations in mineral dressing and the development of process equipment for the chemical industry, construction, mining, and metallurgy.

Recovery of bioactive complex from brown algae by alternative extraction approaches

Arctic brown algae are a valuable source of many bioactive compounds. The study presents an approach for obtaining a complex extract that combines the beneficial properties of all compounds instead of isolating narrow fractions, which is the focus of most seaweed processing technologies. The study examined the efficiency of conventional, ultrasonic, and microwave extraction with 40 % isopropanol as a non-conventional solvent. Ultrasonic pretreatment and swelling had a positive effect on the extraction of mannitol, pigments, and polyphenols. Microwave extraction resulted in extracts enriched with mannitol and polysaccharides. Strong positive correlations between radical scavenging, ferric reducing, and iron-chelating activities and the contents of pigments and polyphenols in the extracts were revealed. Thus, the proposed techniques, together with the specific solvent, show promise in replacing conventional solvents in plant biomass processing to obtain complex extracts. Due to their bioactive properties, they have promising potential for use in pharmaceuticals, veterinary medicine, and agriculture.

Correlation between Turbidity and Inherent Optical Properties as an Initial Recognition for Backscattering Coefficient Estimation

Seawater turbidity is a common water quality indicator measured in situ and estimated from space on a regular basis. However, it is rarely correlated with the inherent optical properties of seawater, which convey information about seawater composition. In this study, we show a simple application of the turbidimeter’s weighting function in the estimation of the backscattering coefficient of a model inorganic suspension in seawater. First, we introduce a method to measure the instrument’s weighting function which describes the sensor’s angular response in terms of scattering angles. The determination of the sensor-specific weighting function led us to characterize its angular sensitivity to the presence of suspended particles. The highest sensitivity for the Seapoint turbidimeter is in the range of 114°–128° (containing 25% of the total signal). Next, we describe the correlations between turbidity and the scattering and backscattering coefficients on the example of the model of inorganic particle suspension using the calculations based on Mie theory. The correlations are analyzed for narrow size fractions of the particle size distribution of silica in the range of 0.59–190 µm. We established that there is a good linear correlation (characterized by the coefficient of determination r2 = 0.979) between the part of the scattering coefficient measured by the turbidimeter and the backscattering coefficient of all size fractions of the model inorganic suspension.

Випробування кумарон-інден-карбазольної смоли та модифікованих нею бітумів

DOI: 10.31081/1681-309X-2024-0-1-26-33 Specialty 161. U.D.C. 665.775.4 TESTING OF COUMARONE-INDENE-CARBAZOLE RESIN AND BITUMEN MODIFIED BY IT © Yu.V. Prysiazhnyi, PhD in Technical Sciences, S.V. Pyshyev, Doctor of Technical Sciences (Lviv Polytechnic National University, 12, S. Bandera Str., Lviv, 79013, Ukraine) The article shows the importance of research aimed at obtaining road bitumen modifiers from nontarget products of coal thermal processing, in particular, by further processing of high-boiling fractions that are separated from liquid coal coking products. The results obtained in this area indicate the effectiveness of using modified coumarone-indene-carbazole resins as a polymeric modifier of road oil bitumen. Laboratory tests were carried out. As starting materials, we used bitumen of BND 70/100 grade, obtained at PJSC “Ukrtatnafta”, and coumarone-indene-carbazole resin synthesized by ionic cooligomerization from a narrow coumarone-indene fraction (140-190 °C) and carbazole. The modification of road bitumen with coumarone-indene-carbazole resin was carried out to determine the quality characteristics of the resulting modified binder. By changing the mass content of coumarone-indene-carbazole resin in bitumen, several series of modification were performed. The resin consumption was set based on the consumption of industrial adhesives – 0.1 to 2.0 % by weight. The conditions for mixing the modifier with bitumen were as follows: temperature – 190 °C; duration – 60 minutes; modified Reynolds criterion – 109500. Using the modified bitumen, an asphalt mix was prepared, the corresponding asphalt concrete was produced and its quality was analysed. It was found that modification of BND 70/100 road bitumen with coumarone-indene-carbazole resin significantly improves its adhesion, while slightly deteriorating its thermoplastic properties. Coumarone-indene-carbazole resin ultimately improves the physical and mechanical properties of ASG.Dr.Sh.A.NP.I. asphalt concrete, in particular, the water saturation and compressive strength at 20 °C. Keywords: oil processing, coal processing, bitumen, modification, coumarone, indene, carbazole, resin. Corresponding author: Yu.V. Prysyazhnyi, e-mail: yurii.v.prysiazhnyi@lpnu.ua

Approximation method for the potential composition of petroleum fractions

The paper gives a brief review of mathematical models of potential composition of oil fractions. The stages of obtaining approximating dependence of the fractional composition of oil are defined. A multicomponent mixture is represented as a discrete series of narrow hydrocarbon fractions. Each of them is characterized by its average boiling point. The results of approximation obtained for oil of different fields are given. The criterion for choosing dependence is the sum of squared deviations of factored values from experimental (reference) values. The following approximating dependencies of the curve of true boiling points for oil of different deposits are obtained. They are cubic parabola, power function, arctangence, exponentiation function, cubic parabola-arctangence. It is shown that the best results are obtained for combined ‘cubic parabolaarctangent’ model. In case of data deviation on oil fractional composition coming from chemical analytical laboratory coefficients are corrected in TBP approximation. Oil fractional composition awareness is important when choosing the direction of oil refining, in process and simulation modeling, when determining the top performance of processing units.

НИЗКОЦЕМЕНТНЫЙ ОГНЕУПОРНЫЙ БЕТОН НА ОСНОВЕ ЗАПОЛНИТЕЛЯ ИЗ КАОЛИНОВОГО ШАМОТА С УЛУЧШЕННЫМИ ПОКАЗАТЕЛЯМИ УДОБОУКЛАДЫВАЕМОСТИ

The paper presents the results of developing low-cement fireclay concrete based on kaolin chamotte. As a result, concrete with the highest application temperature of up to 1500 °C was obtained. The use of narrow fractions of chamotte with low (less than 5%) water demand ensures the production of low-cement concrete with high rates of mobility of the concrete mixture. The research focused on the influence of the additions of sodium tripolyphosphate, reactive alumina and superplasticizers based on naphthalene and polycarboxylate on the spreadability of the concrete mixture and the basic heat-resistant properties of concrete. The use of sodium tripolyphosphate most contributes to the sintering processes of cement stone in concrete. The developed heat-resistant concrete is haracterized by high compressive strength (more than 50 MPa after the first heating to operating temperatures) and heat resistance (at least 20 water heat cycles).

Study of the characteristics of organic mining materials affecting their explosive properties

The article analyzes the explosive and fire-hazardous properties of coal dust of various dispersions using the example of coal mine dust. The authors proposed sample preparation methods for obtaining and studying dust fractions with a dispersity of less than 800 microns. The results of a study of the shapes of dust particles are presented. To study the characteristic particle sizes the authors suggested using the optical microscopy method implemented using a LEICA DM 4000 microscope and the “Image Scope Color” information processing application. To assess the reactivity of dust particles, the authors used a simultaneous thermal analysis method implemented using an STA 449 F1 Jupiter with NETZSCH Proteus Software. The results of a thermogravimetric study of narrow fractions of organic coal dust are presented. The influence of dispersion on the explosive properties of dusts has been established. The results obtained showed the need and expediency of further study of precisely fine fractions of explosive dusts of this kind.

Synthesis of zeolite materials based on dispersed microspheres from fly ash from coal combustion and their sorption properties in relation to Pb(II) and Cd(II)

The influence of the composition of two narrow fractions of dispersed microspheres from fly ash from coal combustion and synthesis conditions on the production of microspherical monozeolite materials of a certain structural type was studied. The possibility of using synthesis products as Pb2+ and Cd2+ sorbents was assessed. It has been established that zeolitization products based on microspheres with a high content of glass phase (more than 90 wt. %) are monolithic solid materials of the geopolymer type, consisting of agglomerated microsphere residues and zeolite phases and, depending on the synthesis temperature, contain mainly one zeolite phase – NaX (FAU), NaP1 (GIS) or analcime (ANA). A simultaneous increase in the alkali concentration and the temperature of hydrothermal treatment led to a deeper transformation of glass microspheres and partial agglomeration of product particles with the formation of granules up to 100 microns in size. The product of alkaline activation of microspheres with a lower glass phase content (~65 wt. %) is a dispersed material based on unreacted microspheres, zeolite phases, mullite and quartz. Most zeolite products in the low Pb2+ and Cd2+ concentration range (not higher than 20 mg/l) were characterized by high solution purification parameters – KD up to 105 ml/g, the degree of extraction was up to 99%, while the most effective were sorbents based on zeolite phases NaP1 and analcime. Sorption isotherms of Pb2+ and Cd2 were approximated using the Langmuir, Freundlich, and Dubinin-Radushkevich models. It has been established that the sorption of heavy metals from dilute solutions is best described by the Freundlich and Dubinin-Radushkevich models. It has been shown that Pb2+/Cd2+ exchange forms of zeolite materials as a result of thermal exposure at 1000 оC undergo a phase transformation with the formation of mineral-like feldspar phases including lead (PbAl2Si2O8) or cadmium (CdAl2Si2O8).

Study on Regularities of Polyethylene Waste Low-Temperature Pyrolysis

A low-temperature pyrolysis with pyrocondensate as a target product is one of the options for processing polyethylene waste. The fractional composition and properties of the pyrocondensate obtained at different temperatures and times were studied. Pyrocondensate was separated into gasoline, diesel fractions, and the residue. The composition and properties of mentioned fractions were established and related to the conditions of the pyrolysis process. X-ray fluorescence analysis of pyrocondensate and narrow fractions isolated from it was carried out.

Effect of Size-Distribution Environment on Breakage Parameters Using Closed-Cycle Grinding Tests.

The so-called population balance model (PBM) is the most widely used approach to describe the grinding process. The analysis of the grinding data is carried out using-among others-the one-size fraction BII method. According to the BII method, the breakage parameters can be determined when a narrow particle size fraction is used as feed material to the mill. However, it is commonly accepted that these parameters are influenced by changing the particle size distribution in the mill. Thus, this study examines the breakage parameters through kinetic testing in different natural-size distribution environments generated by closed-cycle grinding tests that simulate industrial milling conditions. The differentiation of the milling environments was accomplished using various reference sieves in the closed-cycle tests. The experimentally determined breakage parameters were back-calculated and then used to simulate the closed-cycle tests using the MODSIMTM software. Additionally, the energy efficiency was evaluated based on the specific surface area of the grinding products and the energy consumption. The results of the kinetic tests showed that the breakage rate of the coarse particles increases as the aperture size of the reference sieve decreases, and consequently, the content of fines in the mill increases. The back-calculated breakage parameters can be reliably used to simulate closed-cycle circuits, thus helping control industrial milling operations.

Solid-Phase Extraction at High pH as a Promising Tool for Targeted Isolation of Biologically Active Fractions of Humic Acids.

A search for novel sources of biologically active compounds is at the top of the agenda for biomedical technologies. Natural humic substances (HSs) contain a large variety of different chemotypes, such as condensed tannins, hydrolyzable tannins, terpenoids, lignins, etc. The goal of this work was to develop an efficient separation technique based on solid-phase extraction (SPE) for the isolation of narrow fractions of HS with higher biological activity compared to the initial material. We used lignite humic acid as the parent humic material, which showed moderate inhibition activity toward beta-lactamase TEM 1 and antioxidant activity. We applied two different SPE techniques: the first one was based on a gradient elution with water/methanol mixtures of the humic material sorbed at pH 2, and the second one implied separation by a difference in the pKa value by the use of sequential sorption of HS at pH from 8 to 3. SPE cartridges Bond Elute PPL (Agilent) were used in the fractionation experiments. The first and second techniques yielded 9 and 7 fractions, respectively. All fractions were characterized using high-resolution mass spectrometry and biological assays, including the determination of beta-lactamase (TEM 1) inhibition activity and antioxidant activity. The acidity-based separation technique demonstrated substantial advantages: it enabled the isolation of components, outcompeting the initial material at the first step of separation (sorption at pH 8). It showed moderate orthogonality in separation with regard to the polarity-based technique. Good perspectives are shown for developing a 2D separation scheme using a combination of polarity and acidity-based approaches to reduce structural heterogeneity of the narrow fractions of HS.

ПОЛІЕТИЛЕНОВІ ВІДХОДИ – СИРОВИНА ДЛЯ ОДЕРЖАННЯ КОМПОНЕНТІВ МОТОРНИХ ПАЛИВ

One of the options for utilization of polyethylene waste is low-temperature pyrolysis, the target product of which is pyrocondensate. In the work, the fractional composition and properties of the pyrocondensate of pyrolysis of polyethylene waste were studied. It was established that pyrocondensate and its fractions practically do not contain heavy metals characteristic of oil fractions. Pyrocondensate is divided into gasoline, diesel fraction and residue. The composition and properties of these fractions were studied in detail. X-ray fluorescence analysis and IR spectroscopic studies of pyrocondensate and its separate fractions were carried out. It was established that narrow fractions of pyrocondensate and residue can be used as components of commercial fuels only after additional processing.

Low-cement refractory concrete based on kaolin chamotte aggregate with improved workability

The results of the development of low-cement refractory concrete (LCC) based on a filler made of kaolin chamotte with a maximum application temperature of 1500 o C are presented. It is shown that in order to obtain high rates of workability, narrow fractions of filler with reduced water demand should be used. A comparative analysis of the effectiveness of superplasticizer additives has been carried out, their effect on the properties of kaolin chamotte-based LCC has been evaluated. It is established that the use of kaolin chamotte provides high strength of refractory concrete (more than 50 MPa after drying and first heating to operating temperatures).

Element Composition of Fractionated Water-Extractable Soil Colloidal Particles Separated by Track-Etched Membranes

Membrane fractionation with track-etched membranes was used to size-profile the microelement composition of water-extractable soil colloids (WESCs). The aim of the study is the element composition of narrow WESC fractions of typical chernozems in the range of 0.01–10 µm. Micro-/ultrafiltration through a cascade of track-etched polycarbonate membrane filters with pore sizes of 5, 2, 1, 0.8, 0.4, 0.2, 0.1, 0.05, 0.03, and 0.01 µm at room temperature was used. ICP–AES using direct spraying of obtained fractions without decomposition was used; Al, Ba, Cd, Cr, Cu, Fe, Mn, Si, Sr, Ti, Zn, Ca, K, Mg, Na, P, and S were found. Narrow WESC fractions differ significantly. For macro- and microelements, maximum amounts of Si, Al, Fe, and Ti and their maximum percentages are observed in fractions with sizes above 1 µm, while Ca, Mg, Mn, Cu, Zn, K, and S are accumulated more in fractions with sizes below 1 µm. The developed approach provides preparative isolation of a detailed set of narrow WESC fractions in the micrometer–nanometer range. This provides element soil profiles that reveal distinct differences and the individual character of each fraction as well as trends in changes in the mineral matrix and microelement composition with fraction size.