Home – Home – Jornals – Chemistry for Sustainable Development 2017 number 3

The article summarizes the results of the studies performed at the Institute of Chemistry and Chemical Technology SB RAS from 1998 to 2014 in the area of thermocatalytic transformations of brown and sapropelite coal into gaseous and liquid fuels, binding and carbon materials. The fundamentals were developed for the autothermal process of brown coal carbonisation in a fluidized bed of catalyst with obtaining semi-coke and carbon sorbents. Additionally, the simultaneous preparation of fuel gas and syngas based on parallel operation of two fluidized bed reactors that are pyrolyser and gasifier was studied. Due to the use of a fluidized bed of catalyst particles during oxidative carbonization of brown coal, we managed to combine in one apparatus the processes of combustion and thermal treatment of coal. Metallurgical slags capable of oxidizing volatile substances released from coal were used as catalysts at elevated temperatures. The developed method allowed regulating the degree of coal carbonisation and, respectively, the properties of the resulting carbon products by changing the consumption coefficients of powdery coal and air fed to the reactor. Herewith, the depth of thermal treatment of coal and such characteristics of the resulting carbon product, as the heat of combustion, a content of volatile substances, its chemical composition and porosity were changed. Only the most reactive part of fuels was gasified in a catalytic boiling layer in a mode of partial gasification of coal and the porous carbon product was formed, the latter could be used as a sorbent. It was proposed to produce syngas by using a pyrolyser-gasifier. Semi-coke formed during brown coal carbonisation in a pyrolyser was raw materials for steam gasification. Since the major part of volatile substances was already removed from semi-coke, the release of resinous products did not accompany its gasification. Therefore, the product gas did not require expensive purification from impurities before its use in synthesis processes. New methods for the preparation of liquid fuels and road binders were proposed. They were based on the process of hydrogenation of brown coal and its mixtures with oil residues and synthetic polymers in the presence of mechanically activated iron-ore catalysts in the environment of hydrogen donor solvents. Products of joint refining of brown coal, oil residues and synthetic polymers wastes were used to obtain road binders, and it was proposed to obtain modifiers for paving asphalt based on oil-resistant rubbers and liquid coal products. The optimum conditions for thermal refining of sapropelite coal in a reactor with a fluidized bed were selected. They provided the increased yield of liquid products in comparison with the known processes of semicoking of coal. The composition of the products allowed their refining by standard oil refining technologies.

The optimum conditions for the synthesis of enterosorbents of birch bark bast were determined by experimental and calculation methods. The regression equations describing the dependence of characteristics of enterosorbents from conditions of its synthesis were obtained. The optimum conditions for the preparation of an enterosorbent with the maximum sorption activity for methylene blue and containing less than 5 mass % of water soluble substances were calculated using these equations: NaOH concentration of 1.5 mass %, a temperature of 80 °C and treatment duration of 60 min. Calculated values correlate well with experimentally obtained results.

The structure and the first hydrolysis step of the hydrated Pu(IV) ion in the aquatic environment were studied using relativistic density functional theory and the polarizable continuum model (PCM). According to calculations, the Pu(IV) ion was mainly coordinated with eight water molecules. The calculated distance Pu-O of 238-241 pm was in good agreement with the experimental value ((239±2) pm). It was demonstrated that for the correct replication of constants log K ₀¹ of the first hydrolysis step, it was important to use scaling multipliers adequate to the charge of the hydrated complex when constructing the density that included the solvated complex in PCM model. The calculated values of log K ₀¹ of 1.1…-0.2 were close to the experimentally defined range (-0.6…0.6). The correct replication of hydrolysis constants allowed considering the calculated range of the hydratation free energies of the Pu(IV) ion of 6070-6157 kJ/mol as a reasonable prediction of experimental values.

The paper presents the results of the study on the effects of objects of the Karakan coal cluster (Kuzbass) on the atmosphere. Observation of the composition of atmospheric suspension was carried out for 3 years - from 2012 to 2014. It was demonstrated that particles of less than 1 and 10 µm were found in a considerable proportion (to 50 and 71%, respectively) in atmospheric suspension of a number of sampling points throughout the observation period. These points are located near technological and motor roads, quarries. The qualitative composition of suspended particles demonstrated high contents of coal particles with multiple inclusions of native metals and their compounds (including rare earth elements). Rare-earth phases have a potentially hazardous inhalable size - from nanoscale to tens of microns. As a whole, as demonstrated by our three-year observation, all studied regions of the Karakan coal cluster are unfavourable for living from the viewpoint of air quality.

The paper gives assessment of the content of polychlorinated biphenyls (PCB) in the upper water layer and deep water levels (900-1500 m) of Lake Baikal at the current stage. The total concentrations of PCB congeners (PCB content from 24 to 34 congeners) are varied in a range of 1.4-7.2 ng/dm³. Domination of tri-, tetra- and pentachlorinated biphenyls in a series of PCB homologs has been observed, which points out at long-range atmospheric transport as a major source of PCB. Polychlorinated biphenyls content in the upper water layer of Lake Baikal is comparable or significantly lower in comparison with that of water in continental world lakes but higher in comparison with Arctic and Antarctic lakes. Commercial fish species omul (C. migratorius Georgi, 1775) were proposed as a biomonitor of PCB in the Baikal ecosystem. By the accumulation level of seven indicator PCB congeners (Nos. 28, 52, 101, 118, 138, 153 and 180 by IUPAC) in omul and bulltrout (Salmo trutta) from highland lakes of South and Central Europe, the amounts of bioavailable PCB in water of these lakes are comparable between each other. The results of approbation of the method for determination of indicator PCB congeners in water and omul samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) and isotopically labelled internal standards may form the basis of the modern system of monitoring of persistent organic pollutants in the Baikal ecosystem.

The reaction of 3-(3,4-dimethoxyphenylethyl)aminomethylidene-1,2,3,9-tetrahydropyrrolo[2,1-b]-quinazoline-9-one (3a), 4-(3,4-dimethoxyphenylethyl)amino)-methylidene-1,2,3,4-tetrahydropyrido[2,1-b]-quinazoline-10-one (3b) and formaldehyde in acid medium was studied. Instead of the expected Mannich products, bis-derivatives that are deoxyvasicinone and homoveratrylamine were obtained from 3а, and mackinazolinone - from 3b. The structure of the synthesized compounds was confirmed by data from IR, NMR and mass spectroscopy.

Natural zeolites modified by rare earth element (REE) ions are promising to obtain efficient regenerative stimulants and biologically active drugs. Rare earth elements are used upon treatment of tuberculosis, tumours, skin diseases, and REE of cerium subgroup have anticoagulative action. Europium introduced into the zeolite matrix exerts neuroprotective effects. It is considered reasonable to use potassium channel blockers with the aim of reducing ischemic brain damage. Lanthanum, cerium, praseodymium, and europium ions in biological systems substitute calcium ions block their entrance into cells exerting inhibitory effects on the development of calcium-induced cascade of pathologic reactions in cerebral ischemia [4]. Sorption technology allows increasing biological activity of natural zeolites that act as a prolonging carrier of REE ions. Equilibrium and sorption kinetics of europium (III) ions from sulphate solutions by natural mordenite-containing tuff were studied. The kinetic parameters of the sorption process were defined; adsorption isotherms of europium ions were constructed. It was determined that both external and internal diffusion were the rate-limiting step; europium was completely extracted from diluted solutions (<0.0025 mol/L).

Reactivity data of (R)-4-menthen-3-one and routes of its transformations with the participation of hydride, sulphur and nitrogen-containing reactants were generalized and systematized. An opportunity to prepare a range of new potentially pharmacologically active sulphides, sulphoxides, acetamides and an oxime of the menthane series based on (R)-4-menthen-3-one and its derivatives was demonstrated using the Ritter reaction, nucleophilic and electrophilic thiating, nitrosation, oximation. Resulting from the carried out systematic research of reactions of (R)-4-menthen-3-one and its derivatives with aluminium- and boron-containing hydride reagents, it was detected that i-Bu₂AlH was the most stereospecific hydride reducing agent for (R)-4-menthen-3-one to (1R,3R)-n-menth-4-en-3-ol. It was found that the BH₃ x THF complex was a stereospecific hydride agent for the oxo group of (R)-4-menthen-3-one and regiospecific but a low-stereoselective hydroborating reagent for its multiple bond and that of (1R,3R)-n-menth-4-en-3-ol.

Composite materials based on α-alumina reinforced by carbon nanotubes were prepared. Synthesis of materials was performed by mechanochemical mixing of Al₂O₃ nanoparticles with pre-ultrasonicated 0.5-3 mass % multiwall or single-wall nanotubes. The resulting pressed powder was characterized by a uniform distribution of nanotubes. Green body consolidation was carried out by cold isostatic pressing followed by vacuum sintering and successive isostatic pressing at 200 MPa and temperatures not higher than 1520 °C. It was found that the density of the resulting composite material achieved under such experimental conditions was nearly theoretical and nanotubes have not been considerably damaged by the reaction between carbon and alumina. Introduction of carbon nanotubes in the alumina matrix proved to be ineffective in terms of mechanical properties (hardness, bending strength) enhancement when compared with pure alumina ceramics made of the same alumina powder. This is likely due to poor interface quality between a nanotube and the matrix. It was found that the density of the resulting ceramic material was close to theoretically possible; however, the destruction of nanotubes due to the reaction with alumina did not happen. It was demonstrated that the introduction of CNT into the alumina matrix based on nanopowders did not contribute to the improvement of mechanical (hardness, bending strength) features compared to the non-doped material. Apparently, this was due to a poor chemical interface at the phase boundary.

The precipitation of bismuth (III) from nitric acid solutions depending on the concentration of malate ions, process temperature, pH values of solutions upon the addition of an optically active L(-)-isomer and racemic DL-malic acid was studied by X-ray phase analysis (XPA) methods, IR and Raman scattering spectroscopy (RSS), thermogravimetry and chemical analysis. It was demonstrated that bismuth malate monohydrate with a composition of BiC₄H₃O₅ x Н₂О was precipitated when adding L(-)-malic acid into nitric acid solutions, and in case of the addition of DL-malic acid, a compound with a composition of BiC₄H₃O₅ x 0.5Н₂О is formed. Coordination of the bismuth cation with malic acid anions was studied by spectroscopic methods. It was found that malic acid residue in the compounds under study was thrice deprotonated, and their bond with the bismuth cations was carried out through all functional groups of malic acid, The conducted research of obtained bismuth malate demonstrated that L -malate samples in comparison with bismuth DL -malate were homogeneous by the particle size distribution, which does not require the additional cost on grinding the sample to a homogeneous state when using it as a medicinal substance, and an increase in process temperature allows obtaining more fine-grained powders. The advisability of the preparation of bismuth malate for medical purposes from bismuth metal was demonstrated with preliminary oxidation of the latter with air oxygen, dissolution of the resulting oxide in nitric acid (1 : 1) and precipitation of bismuth (III) malate by the addition of a bismuth-containing solution to a sodium malate solution with a molar ratio of malate ions to bismuth of 1.1-1.2 and process temperature of (60±10) °С.

The paper presents the results of a thermogravimetric study of coal vitrinite of different metamorphic stages. It was demonstrated that initial mass loss temperature increased, the rate of gum formation and gassing decreased, and maximum thermal decomposition of coal material shifted in the DTG curve to a higher temperature region with an increase in metamorphic grade of vitrinite during their pyrolysis in inert atmosphere at 300-600 ^oС temperature range. When studying the effect of heating rate for the destruction process of vitrinite organic matter it was found that an increase in the maximum rate of thermal decomposition happened in the DTG curve and temperature, whereby it was reached.

This paper proposes a new approach to the development of new sorption materials designed for extraction of compounds of high toxic heavy metals from wastewater, pollution by which is of global environmental problem. To obtain new sorbents it is proposed to use large-tonnage wastes of wood chemistry, i. e ., lignin, organochlorine residues from epichlorohydrin production and the waste of processing of high sulphur crude oils and natural gas, elemental sulphur, which allows simultaneously solving the problems of waste disposal and wastewater treatment. The availability of sorption materials using lignin previously subjected to chlorine water was demonstrated. Sorbents containing 2.4-12.5 % of sulphur are formed in 91-93 % yields by the interaction between the product with different degrees of chlorination and sodium disulphide in hydrazine alkaline system. Their maximum opportunity for heavy metal removal (Ni, Zn, Cd, Pb, Hg, Cu, Co) from model solutions with initial metal ion concentration in solution of 5000 mg/L was explored. High sorption activity of the resulting materials was detected for all the studied metals. A new type of sorbents was also prepared when using chlorinated lignin (chlorine content of 5.7 %), sodium polysulphide (Na₂S_n, n = 1.5-4.0) and wastes from epichlorohydrin production, the main component of which is 1,2,3-trichloropropane (86.2 %). The materials obtained herewith contain from 18.3 to 65.0 % of sulphur and generally show higher sorption activity toward the studied metals than sorbents obtained without the use of organochlorine residues.

The work studied the catalytic combustion of heavy coal-tar products (HCTP) formed upon processing of Baltic shales to assess the efficiency of combustion in the presence of an Al-Cu-Cr oxide catalyst of complete oxidation of organic compounds with active component contents of 10 %, the optimum temperature modes of catalytic combustion were determined and an assessment of an opportunity for carrying out fuse combustion process in a boiling layer of a catalyst without using additional fuels was performed. It was demonstrated that the maximum degree of combustion of 97.7-97.8 % was reached at 700-750 °С. Herewith, the concentrations of harmful substances in exhaust gases were the following: СО 244-269 ppm; NO_x 179-229 ppm; SO₂ - is absent. Based on the literature data on catalytic combustion of oil containing sulphur, it was demonstrated that the SO₂ concentration at the outlet of the reactor could reach the value of 60 ppm during long-term operations of the setup for catalytic combustion of HCTP in autothermal mode considering the calcium oxide content in their mineral component. The carbon content in bottom ash amounted to 2.3-2.4 %. By the calcium oxide content, ash refers to basic fly ash and can be used as an additive to cement. Based on the results of catalytic combustion of HCTP in autothermal mode in a laboratory setup, emission of harmful substances in exhaust gases was determined using HCTP as fuels for a catalytic boiler-house with the air excess coefficient α = 1.2.

Being natural surfactants, organonitrogen bases affect the behaviour of oil disperse system in-situ conditions and upon technogenic exposure on oil fluids. In this regard, characteristics of major compounds of highly paraffinic oils and resulting asphalt-resin-paraffin deposits are important for understanding participation of these compounds in the formation of organic deposits. The work studies the distribution and composition of organonitrogen bases in highly paraffinic oil and a model of asphalt-resin-paraffin deposits obtained there from under laboratory conditions. Concentrates of high and low molecular mass bases are isolated using sedimentation techniques, extraction, and liquid adsorption chromatography on impregnated oil and sediment sorbents. High molecular mass compounds with a strongly developed alkyl skeleton prevail among highly paraffinic base oils. The fraction of these compounds is higher in sediment than in oil, which indicates their predominant participation in deposit formation. The composition of the isolated bases was characterized by IR and NMR spectroscopy, and chromatographic-mass spectrometric method. According to the structural-group analysis, average molecules of organonitrogen bases of oil and residue consist of polycyclic nucleus involving aromatic and saturated cycles with various alkyl skeletons. Average molecules of high molecular mass compounds with strongly developed alkyl substitution (the number of carbon atoms in the alkyl chain (29-32)) may contain 2-3 aromatic and 4-5 saturated cycles. Weakly alkylated (three to five carbon atoms in the alkyl chain) high molecular mass bases are more cyclical due to the development of both aromatic (K_a = 6-9) and naphthene rings (K_n = 10-13). Alkyl substituents in the structure of their average molecules are presented by methyl groups only. According to the results of chromatography-mass spectrometry studies, the composition of low molecular mass compounds of oil and asphalt-resin-paraffin deposits is characterised by identical sets of alkyl-substituted quinolines, benzo-, dibenzoquinolines, and azapyrenes, among which alkylbenzoquinolines prevail.

The paper presents the results of biological tests of granular complex humic fertilizers (CHF) with the addition of carbamide (urea) and simple superphosphate. CHF samples were obtained from lignite (brown coal) of the Tisulskiy deposit (the Kaychakskiy plot, Kemerovo Region), their production method is given. Samples of complex granular fertilizers, initial coal and humic acids (HA) were characterized using ¹³С CP/MAS NMR, technical and elemental analysis. An integral indice, i. e. the index of phytoactivity (IP) that was calculated as the average value of the sum of indicators of the germinative energy, the seedling height (SH) and root length of seeds was used for objective testing. It was performed on seeds of spring wheat Iren by soaking them in an aqueous solution of CHF. Seeds were germinated under the conditions of GOST 12038-84. The effect of major components that were HA and mineral additives contained in the composition of CHF was determined. It was found that alongside with the composition of CHF, the functional group composition parameters might affect biological activity. It was demonstrated that the synergistic effect of HA and introduced mineral additives was observed. The presence of HA in CHF allowed decreasing the concentration of the solution to soak seeds without decreasing its biological activity. The tested CHF showed high phytoactivity (IP = 1.19-1.45). The maximum biological activity was noted in samples treated with superphosphate. The ability of HA to decrease the suppressive effect of large concentrations in solutions of mineral fertilizers was determined.

Major characteristics of cellulose obtained from fruit shells of oat by the hydrotropic method were studied. It was demonstrated that bleaching of technical cellulose sample contributed to cellulose concentration and the removal of the bulk of noncellulosic compounds in the product. Samples of esters close by major characteristics to mastic-lacquer colloxylins were synthesised under conditions of preparation of highly soluble cellulose nitrates. Cellulose fibres of fruit shells of oat and cellulose nitrates obtained were characterized by scanning electron microscopy (SEM) techniques. It was found by IR spectroscopy that hydrotropic cellulose was identical to cellulose from traditional types of plant raw materials by major adsorption bands. It was demonstrated that the resulting esters were cellulose nitrates.