AbstractA comprehensive study of an industrial line for the pelletization of sawmill by-products was carried out. The energy efficiency of its operation, the impact on the environment, and the cost of electricity for the main and auxiliary equipment were determined. Recommendations were proposed to reduce the specific consumption of fuel and electricity and the emissions of harmful ingredients in the production of pelletized biofuels.

AbstractThe formation of metal-bearing coalfields of the Raichikhinskoe deposit in the conjugation zone of distributive provinces of the Bureya uplift and coal-accumulation areas of the Zeya–Bureya sedimentary basin was studied. It was established that it occurred under conditions of the successive extraction of ore components from weathering crusts of the Bureya uplift, transportation, and unloading in the paleodelta of the Bureya River. These processes proceeded synchronously with volcanic activity in the Sikhote-Alin orogenic belt, which is associated with the supply of volcanic ash. The association of these events made it possible to distinguish two types of enrichment of the Raichikha coals in rare earth elements and yttrium (REY): terrigenous with the supply of REY by surface waters and combined terrigenous volcanogenic associated with the shedding and leaching of acidic and alkaline volcanic ash. The cerium group lanthanides predominate in coals and their combustion products. The largest fraction of REY was contained in fly ash (0.11% on a total weight basis). The mechanisms of accumulation of ore components at the stage of peat deposits are considered from the standpoint of the localization of trace ore components as clastogenic mineral forms and under the conditions of interaction of ore solutions with the organic environment of peat bogs. The quality of REY was assessed, and the most enriched sections of the Verkhnii layer were identified. Prospects for the extraction of lanthanides from coal are considered from the standpoint of the possible recovery of a number of rare, nonferrous, and noble metals in this process.

AbstractThe levels of concentrations of valuable impurity elements in coals from a number of Sakhalin deposits were studied. It was established that all the studied deposits are potentially commercial metal-bearing in terms of Sc, REEs, Cs, Rb, and Sr. A wide range of valuable metals with minimal commercial concentrations—Ge, Sc, Mo, Y, W, Cs, Rb, Sr, and Sb—was identified in the Novikovskoye germanium–coal deposit (sections Vostochnyi 1 and Rezervnyi). An estimate of the predicted resources of valuable metals in this deposit was made, and the large resource potential of valuable metals in the coals of Sakhalin was concluded.

AbstractThe adsorption of 2,4-dichlorophenoxyacetic acid on the samples of activated carbons modified with iron compounds to acquire magnetic properties of these samples was studied. The formation of the magnetic particles of iron oxide compounds, which make it possible to technologically simplify the phase separation system after adsorption, on the adsorbent surface was found by XRD analysis. A slight decrease in the adsorption capacity of the samples modified with iron compounds allows one to use them for wastewater treatment in order to remove the herbicide studied in the work.

Abstract–To master the pyrolysis characteristics of oil shale under diverse conditions, we analyzed Huadian oil shale by TG-DTA, FT-IR, and XRD, and compared the effects of heating rate, gas flow rate, pyrolysis atmosphere, and particle size on its pyrolysis behavior. The results show that when the heating rate increases from 5 to 15°C/min, the corresponding temperature increases from 439.1 to 461.6°C, and the mass loss rate increases from 12.42% to 13.51%. When the particle size increased from 0.075 to 0.355 mm, the maximum mass loss rate temperature, termination temperature, and mass loss rate increased, but the initial temperature decreased from 336.1 to 275.8°C. When the oxygen concentration increased from 10 to 30%, the initial temperature, maximum mass loss rate temperature, and termination temperature decreased with the increase of oxygen concentration, but the mass loss rate increased from 17.25 to 17.69%, as well as when the gas flow rate increased from 30 to 100 mL/min, the termination temperature and mass loss rate increased, but the initial temperature decreased from 366.5 to 303.9°C. The Coats-Redfern method was used to calculate the pyrolysis kinetics parameters at different heating rates and different particle sizes. The results show the activation energy increases with increasing heating rates while decreasing with increasing particle sizes. This study is of great significance in optimizing the thermal conversion process of Huadian oil shale as raw material.

AbstractThe influence of the amount of precursors of cobalt and nickel oxides on the composition and structure of catalytic cracking products of heavy oil from the Zyuzeevskoye field was studied. It was found that an increase in the amount of a loaded precursor led to the destruction of a larger amount of resin–asphaltene components and the yield of an IBP–360°C fraction. It was established that nickel-containing catalysts facilitated the destruction of 66% high-molecular-weight components, and cobalt-containing catalysts contributed to a low yield of by-products. The structural group analysis of initial oil asphaltenes and those formed after thermal and catalytic cracking was studied. A possible mechanism of the reactions was presented based on the experimental data.

AbstractVersions of the production of environmentally friendly components of motor fuels using the Fischer–Tropsch synthesis (FTS) are considered. The advantages and disadvantages of the used radial reactors are analyzed. Research on the development of a domestic technology for the production of synthetic liquid fuels from natural gas on a bench-scale process plant, which was used to solve the problems of hydrogen utilization, is described. Based on the results of this work, conclusions that allow the development of a promising scientific and practical direction were drawn.

Abstract–Biomass resources have received considerable attention for their diversified purposes in the areas of energy production and production of other valuable chemicals. Soot is produced as an unwanted product of biomass thermal degradation. Its nature and characteristics have been found to be biomass composition related for carbon related applications. In this study, the structural and chemical properties of soot samples from three (3) different biomass fuels from a low-temperature retort heating reactor were investigated. The samples were characterized using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), Fourier Transform Infra-Red Spectroscopy (FTIR) and Branueur-Emmet-Teller (BET) method. Different structural patterns were observed for the soot samples (I1, I2, and I3) which were attributed to different biomass sources from which the samples were produced. Similar carbon contents (>70%) were measured for the samples as was found from the EDS analysis. Also, it can be inferred that O/C ratios of the three samples were < 0.6 making the samples sources of stable carbon. The FTIR analysis indicated that soot samples were rich in functional groups present in oxygenated hydrocarbons. The three samples had considerably high specific surface areas and porosities with pore sizes ranging from mesoporous (I1 and I2) to microporous (I3) as revealed by the BET results. These carbon-rich materials can be used as precursors to produce activated carbon and other carbon related materials.(Graphical Abstract)

AbstractThe most important thing to know when investigating the feasibility of energy generation from biomass materials is the higher heating values (HHVs). 12 biochars were obtained from zeyrek pulp by hydrothermal carbonization method. Fuel properties (proximate, ultimate and calorific value) and structural properties (by IR spectroscopy) of the obtained biochars were determined. To predict HHVs of biomass, the multi-layer perceptron artificial neural network (MLP-ANN) technique is used. For this purpose, 66 real data points were extracted from both our data and reliable references for the model’s training and validation. Based on input data from the proximate analysis, ultimate analysis and combined proximate-ultimate analysis, three different MLP-ANN models were developed. The prediction accuracies of these models were compared statistically to the experimental data. MLP-ANN models have been shown to predict the HHV of biomass with high accuracy. The performance of the MLP-ANN models was also evaluated and it was discovered that the combined proximate-ultimate analysis based MLP-ANN model providing the best results such as coefficient of correlation (R2), root mean square error (RMSE) and mean absolute percentage error (MAPE).

AbstractThe technology of obtaining carbon sorbents from composites based on phenol–formaldehyde resin for the extraction of precious metals from pulp is considered. The process regimes of the carbonization and the subsequent activation of the sorbents by the action of microwave radiation in a steam and inert gas atmosphere are presented.

AbstractExperimental and calculated data on the characteristics of synthesis gas, which can be obtained by the two-stage pyrolytic conversion of various types of biomass related to wastes from the woodworking industry and agricultural production, as well as industrial and domestic organic wastes, are presented. The variety of properties of the test types of hydrocarbon raw materials made it possible to establish the influence of the characteristics of processed biomass on the characteristics of the resulting synthesis gas (composition, volumetric yield, and heating value). It was found that the ratio H2/CO in the resulting synthesis gas can be purposefully changed by choosing a feedstock with an appropriate H/O atomic ratio. It was proposed to use the volatile content of the processed raw material calculated on a dry ash-free basis as a parameter that determines the energy efficiency of the two-stage process of pyrolytic conversion of biomass into synthesis gas. The range of volatile content corresponding to the maximum values of the degree of energy conversion was established.

AbstractA representative sample of high-moor peat was obtained and characterized. The surface activation of the initial peat by sequential disassembly was performed to obtain lignocarbohydrate materials that differed in composition, structure, and physicochemical properties. The oil capacity of the resulting materials was evaluated, and the thermal characteristics of the initial and kerosene-saturated samples were studied. It was found that the extraction of valuable biologically active components (bitumen and biopolymers of humic nature) led to surface activation with the retained integrity of plant residues. The subsequent treatment with acids led to significant defragmentation, an increase in bulk density, and a decrease in the oil capacity of the samples. It was shown that the low ash content and the possibility of direct utilization as fuel with a high calorific value (31.9–35.4 MJ/kg) make it possible to consider low-ash high-moor peat with a low degree of decomposition as a tool for removing local oil spills.

AbstractThe possibility of using structural carbon materials in molten salt reactors was considered. The influence of the conditions of the main stages of carbon material fabrication processes on the structural and operational characteristics of the resulting materials was analyzed. Directions for the modification of structural graphites were proposed in order to increase their resistance to the internal media of molten salt reactor facilities.

AbstractThe carbonization of carbohydrates (glucose, sucrose, and starch) in an inert gas atmosphere of argon and under the action of calcium chloride and iron(III) chloride additives was studied. It was established that the addition of calcium and iron(III) chlorides exerted a peculiar catalytic effect on the carbonization process. Carbon production can be carried out at lower temperatures to 200°С. In traditional methods of synthesis, carbonization upon the decomposition of carbohydrates occurs at temperatures of 300–800°C. It was found that the process of carbon production was accompanied by the release of heat, which was confirmed by thermodynamic calculations of the chemical reaction of carbon production and experimental studies of the carbonization of carbohydrates by differential scanning calorimetry. A regular decrease in the yield of carbon, as compared to a maximum theoretically possible one, was observed in the order glucose > sucrose > starch. It was established that the heat of combustion of carbon obtained upon the carbonization of carbohydrates under the action calcium and iron chlorides reached 34 MJ/kg or more due to the presence of structural fragments that do not occupy energetically favorable positions compared to the graphite structure. The presence of the structural fragments of carbon was established by X-ray phase analysis of powder diffraction patterns.

AbstractElectronic waste (E-waste)plastic has been found to be a critical danger to the biological system. Electronic waste plastic has been appeared to ascend because of populace development, requiring fruitful decrease. The point of this examination is to think about the proficiency and discharge attributes of an electronic waste plastic oil (EWPO) filled diesel engine with aluminum oxide and manganese oxide nanofluids to diesel fuel. The pyrolysis interaction was utilized to make E-waste plastic oil at maximum yield of 80%, which has brilliant fuel properties. A single cylinder, four-stroke, constant speed, diesel engine was used in the experiments. The sol-gel technique was utilized to make aluminum oxide, and the co-precipitation strategy to make manganese dioxide nanofluids. FTIR and SEM techniques are used to portray the nanoparticles. Nanoparticles are dissolved and mixed with toluene and diesel with 20% EWPO in ultrasonicator with tween 20 as surfactant. The expansion of nanoparticles improved the fuel properties by expanding its surface region to volume proportion. The expansion of nanofluids to aEWPO 2.5% improves thermal efficiency (BTE) and brings down around 0.30 kg/kWh amount of specific fuel consumption (BSFC). The consequences of the investigations show that the expansion of nanofluids reduced carbon monoxide (1%), hydrocarbon (1–2%), and expanded NOx (939 ppm) outflows compared with EWPO20.

AbstractThe combustion processes of brown coal, wood biomass, cardboard, and their mixtures in an oxidizing atmosphere at a heating rate of 20 K/min were studied within the framework of synchronous thermal analysis. The curves of weight loss and differential scanning calorimetry were obtained to describe the combustion processes of individual fuels and solid fuel mixtures with a weight ratio of 50 : 50. The main process parameters of combustion, such as ignition and burnout temperatures and a maximum rate of reaction were determined using analytical and numerical methods. The combustion indices of the fuels and their mixtures were established, and the kinetic parameters of the test processes were calculated. Based on the differential weight loss data, the nature of interactions between fuel mixture components was determined. The high volatile content of wood sawdust and cardboard affected a decrease in the ignition temperature of the mixtures by 15–18%, as compared to that of brown coal. The burning temperature of a mixture with the addition of wood sawdust decreased by 6.5%, and the addition of cardboard affected an increase in the burning temperature of the mixture by 27%.

AbstractMethods for producing fuel briquettes with various finely dispersed fillers of natural and industrial origin, which are capable of oxidation (combustion) reactions, are described. It was established that elastic polymeric bodies, into which finely dispersed fillers of a hydrocarbon nature were preliminarily introduced, were formed after a freeze–thaw cycle of the aqueous solutions of polyvinyl alcohol. Samples of fuel briquettes with a calorific value of 14.2 to 28.8 MJ/kg and a compressive strength of 2.14 to 2.9 MP were obtained for the associated utilization of industrial waste.

AbstractThe formation of oil sediment in highly paraffinic oil in the presence of carboxylic and naphthenic acids was studied. The influence of the concentration and composition of acids on the process of sediment inhibition and the concentrations of paraffins, resins, and asphaltenes in sediments was demonstrated. In the composition of sediments obtained from oil with the addition of acidic reagents, the amount of light n-alkanes increased and the fraction of higher molecular weight hydrocarbons decreased. The concentrations of aliphatic fragments and carboxyl groups in the resins of sediments obtained with the addition of acidic reagents decreased, and the aromaticity coefficient increased. Asphaltenes in the sediment were characterized by a decrease in the concentrations of aromatic structures and carboxyl groups.

AbstractThe concentration, speciation, and localization of rare earth elements in Miocene brown coals from the Sergeevskoe deposit (Amur oblast) have been studied. The total rare earth element content of the test coals (97.43 mg/kg) exceeds the clarke value by a factor of 1.5; the amount of light lanthanides (74.57 mg/kg) prevails over that of heavy ones (7.68 mg/kg). The main concentrators of lanthanides in Miocene brown coals are humic acids. The amount of rare earth elements in water-soluble, ion-exchange, silicate, and disulfide forms does not exceed 5% of the total content with the exception of scandium, 22% of which is associated with silicate minerals such as clays.

AbstractThe results of analytical studies of Primorye coals and their combustion products are presented. Valuable impurity elements were detected in coals, fly ash, and slag, whose concentrations reached minimum industrial ore levels. The regularities of the transition of impurity elements of coals from brown coal deposits in Primorye (the Pavlovsk, Bikinsk (Nizhne-Bikinsk), and Shkotovsk deposits) were found. The volumes of emissions of various metals into the atmosphere and the environment were determined.