INDUCTIVE PARAMETRIC EDDY-CURRENT TRANSDUCER (IPEP) FOR MEASURING ELECTRICAL AND TEMPERATURE PARAMETERS OF WASTEWATER FROM BREWING PRODUCTION

The possibility of using the theory of operation of a differential inductive parametric eddy-current transducer (IPET) for measuring the electrical and temperature parameters of a sample of acidic and alkaline wastewater is investigated. The need for the development of new informative methods for measuring the physicochemical parameters of wastewater is proved, in the realization of which a promising method of purification is selected. On the basis of a differential scheme for switching on two parametric converters: with exemplary purified water and a converter in which a test tube with a sample of waste water from a brewing production is placed, a differential informative method for measuring the electrical and temperature parameters of the liquid under study is proposed, which is based on the analysis of the components of the difference signal of phase shift angles measured electrical components of the switching circuit signals. The basic relationships that describe the operation of the IPET with the sample of the controlled liquid are given. The scheme of switching on differential IPET with a liquid sample, which is placed in a glass test tube, is considered; the differential scheme provides for heating the sample during measurements to simulate the production conditions of brewing production. Universal transformation functions are given that relate the components of the IPET signals with the specific electrical conductivity χt.s. and the temperature t of the wastewater sample from brewing production, that is, the dependence of the phase difference signal Δj on the generalized parameter A and the dependence of the absolute increment in the specific electrical conductivity Δχ on the temperature t of the wastewater sample, in the investigated temperature range.

DEVELOPMENT OF LOW-MELTING GLASSCERAMIC BONDS FOR HIGH RESOURCE DIAMOND-ABRASIVE TOOLS

Research is aimed at creating high-resource diamond-abrasive tools with a large-pore structure of the working layer, the use of which reduces the occurrence of grinding defects when processing materials sensitive to overheating. The formation of an open structure of the working layer ensures effective chip removal, which excludes a decrease in the сutting ability of the tool due to contamination with grinding sludge and creates favorable conditions for intensifying the processing of materials when using high-speed cutting modes. As part of the research, low-melting glass-ceramic binders for diamond-abrasive tools have been developed, which make it possible to increase the tool service life due to the prevention of diamond grains premature destruction and the creation of a large-pore open structure of the working layer. Using a set of calculated data about the main characteristics of glass compositions by factor planning means, the dependences «composition - properties» were determined and the area of optimal compositions of glass-ceramic bonds was established, which ensure sintering of a diamond-containing composite at a temperature of 550–650 °C. The efficiency of the use of alumino-silicate microspheres of technogenic origin as a structure-forming filler providing the formation of a large-pore structure is shown. The features of the chemical and phase composition of the technogenic spheres recovered from the fly ash of the Krivoy Rog TPP have been determined. It has been established that when the diamond-bearing layer of the tool is sintered in the shell of the ash spheres, crystalline new formations with high hardness (hercynite, mullite, maghemite, spinel) are formed. Using ash spheres and developed low-melting binders, which include up to 30 mass. % of glass waste, the laboratory samples of diamond-containing composites with open porosity of 45-50% were made. Studies of their microstructure and morphological features made it possible to determine the pore size (130-200 μm) and establish that during grinding, partial destruction of ash spheres occurs with the formation of additional cutting elements, which increases the tool cutting ability. The research results indicate the advisability of using the proposed approach for selection of the diamond-ceramic composite components and the modes of heat treatment of the diamond-bearing layer when creating a tool. This approach will significantly expand the possibilities of manufacturing large-pore diamond-abrasive tools with a high service life at minimal material costs and will improve the processing of parts made of difficult-to-machine materials.

THE USE OF MULTISUBSTRATE MIXTURES FOR METHANE BIOSYNTHESIS BY AN ADAPTED COMPLEX OF MICROORGANISMS FOR OBTAINING ORGANIC FERTILIZER

Due to the istabiity of market prices for traditional hydrocarbon energy resources and negative impact of their combustion products on the environment, recently quite rapidly develop technology that provide for, first of all, renewable energy sources. One of the promising areas of alternative energy is bioenergy is a branch of biotechnology that considers organic matter of biomass of various origins (mainly agricultural waste) as a fuel source. Among the main advantages of energy biotechnology, it should be noted the speed and relative ease of recovery of the energy substrate, as well as the fact that it is not alien to the environment, so, even if released in quantities exceeding the permissible ones, this will not lead to irreversible changes in the ecosystem. Excess biomass will quickly be incorporated into biogeochemical cycles, which is the key to minimizing environmental damage. The process of bioconversion of methane from organic substrate compounds (carbohydrates, proteins, nucleic acids, lipids, organic acids, alcohols), which in three stages, is called methanogenesis. This process involves a specific complex bacterial enzyme system, consisting of the following coenzymes: methanofuran, tetrahydro-methanopterin, coenzymes F420 and F430, coenzyme M (CoM), coenzyme B. Using of ways of processing and waste disposal, that based on alternative biological recycling methods of organic pollutants does not always allow to achieve the expected effect, in particular on artificially created ecosystems of animal farms working in a closed mode. Concentration on a small area of a significant amount of biowaste (manure, dung, process runoffs etc.) of the cattle kept in the facilities of live-stock industry, contaminates soils, water bodies and atmospheric air with microorganisms, dust, harmful gases and other decomposition products. Often, it is one of the main factors constrainting on the growth of livestock enterprises and agro-industrial complex (AIC) capacities in general, restraining the economic development of regions specializing in agricultural production. For the first time in the region, study was carried out in order to determine the most efficient way to process miskantus phytomass for the production as target products of methane-containing biogas mixture and organo-mineral fertilizer suitable for use in agriculture and forestry. An economically and ecologically attractive way of utilization of wastes of phyto- and zoogenic origin, which makes it possible significantly reduce anthropogenic pressure on the environment, has been proposed.

DEVELOPMENT OF RESOURCE-SAVING TECHNOLOGY OF POROUS-HOLLOW CERAMIC STONES

A resource-saving technology of porous ceramic materials using low-quality non-sintering sandy loam as a basic raw material has been developed. Based on the analysis of the plastic properties of two- and three-component ceramic masses, including sandy loam, expanded clay and fuel slag in various ratios, it was found that the required level of their plasticity provides the content of the main raw material in the following range (wt%): fuel slag – 15 – 20; sandy loam – 50 – 65; expanded clay – 20 – 30. By the method of planning the experiment, the rational composition of the three-component ceramic mass was substantiated. This which contains: 62.5 wt. % sandy loam, 20 wt. % medium-sintering plastic clay as a plasticizer and 17.5 wt. % fuel slag of TPP as a porous agent. For the developed mass, the main technological properties were investigated, which made it possible to recommend the drying mode of the raw material – 60 hours, the optimal firing temperature – 950 °С. Such conditions ensure that samples are obtained without drying cracks and signs of deformation. Оn the results of dilatometric analysis of mass the rational mode of firing high-hollow semifinished products was designed. The firing mode provides for a 44-hour firing and a decrease in the heating rates in the areas of dehydration of clay minerals, direct quartz transition and intensive sintering of the mass, as well as a decrease in the cooling rate in the area of the reverse quartz transition. The proposed firing mode provides the degree of sintering and their properties necessary for ceramic materials. Based on the developed mass under the recommended drying and firing modes, porous ceramic materials with an apparent density of 1.48 g/cm3, a compressive strength of 18.2 MPa and frost resistance of 30 cycles were obtained. The developed materials belong to the group of conditionally effective, and if 50% of the voids are organized, they can be classified as effective.

INVESTIGATION OF THE NEUTRALIZATION PROCESS OF SULFATION PRODUCTS IN THE SURFACTANTS PRODUCTION

The process of sulfation products neutralization in the production of surfactants is not basic, but at this stage the positive effects obtained at the stage of sulfation of organic matter with sulfur trioxide gas are fixed. To preserve the degree of sulfation obtained, it is necessary to carry out the neutralization process under conditions precluding the occurrence of hydrolysis in an acidic medium. The neutralization reaction takes place with a high heat release of about 40 kJ / mol. Analysis of the literature data showed that the neutralization process is not well covered. Little data and hardware and technological design of the process. The process of neutralization in industrial conditions is carried out in apparatus with mechanical turbine mixers, to remove the heat of the exothermic reaction, the paste from the neutralizer is fed into a water-borne heat exchanger and returns to the neutralizer again. The purpose of this study is to determine the optimal technological parameters of the process of neutralization of sulfate products and the development of a mathematical model of this process. The results of experimental studies of the process of sulfation products neutralization with an aqueous solution of sodium hydroxide are presented. During the research, the influence of technological parameters on the quality indicators of neutralization products was determined, the main of which is the degree of sulfation. The optimal technological parameters for carrying out this process in a reactor with a stirrer under laboratory conditions were found. Based on the data obtained in the basis of this process, the use of a continuous-action reactor with a turbine mixer and with a combined heat exchanger. For the transition to an industrial reactor-neutralizer, a mathematical model has been developed, which makes it possible, by means of mathematical modeling, to correct technological parameters in industrial conditions.

ELECTROCATALYTIC COBALT-VANADIUM COATINGS FOR THE HYDROGEN EVOLUTION REACTION

The study of existing energy-saving materials and obtaining the new ones for reducing the cost of the hydrogen production, is relevant for modern hydrogen energy industry. Such properties can be predicted for materials containing vanadium, molybdenum, tungsten and exhibiting catalytic activity for the hydrogen evolution reaction Aforementioned metals can be co-deposited from aqueous solutions with iron subgroup metal-catalysts through the formation of cluster intermetallic compounds with Me-V bond adsorbed on the cathode surface. The induced co-deposition of cobalt with vanadium from the complex citrate electrolyte was investigated in the current work. As a result of the research, it was found that the uniform microcrystalline light-gray high-quality cobalt-vanadium alloy coating is possible to precipitate from a citrate electrolyte with content of 20 g/dm3 vanadium (in terms of metal) as a citrate complex The process was carried out at a current density of 5–10 A/dm2, at a temperature of 30–40°С, pH = 2,8–3,2. The content of vanadium in the coating is 0,37–0,53 % by weight. The maximum vanadium content in the coating is observed at current densities 8–9 А/dm2. The catalytic activity study of the coating that was obtained using cobalt-vanadium alloy in the reaction of hydrogen reduction at the cathode was performed in solution of 2,5М NaOH + 0,02 M NaCl. By increasing the vanadium content in the coating from 0,37 to 0,53% the hydrogen evolution overvoltage is reduced by 0,5 V. It was found that the overvoltage of the hydrogen ion evolution reaction on cathodes from steel 20 with cobalt-vanadium coating is 0.08–0,1 V lower, and the exchange current is higher than on electrodes made of steel 20, which are used in industrial water-alkali electrolysis. This indicates the electrocatalytic activity of the investigated materials for the hydrogen evolution reaction. Electrodes with coating, obtained by cobalt-vanadium alloy can be recommended as a cathode material for the hydrogen electrochemical production. Hydrogen evolution overvoltage reduction also decrease the energy consumption for this process by 15–20 %.

PERICLASE-SPINEL REFRACTORY MODIFIED ТІО2

Over the past decades, the development and improvement of refractory materials for lining high-temperature zones of rotary kilns continues. The main requirements for refractory products for lining rotary kilns for cement clinker roasting are: high density and ultimate compressive strength, low porosity and gas permeability, increased abrasion resistance, low thermal conductivity, high corrosion resistance and the ability to form a protective layer.Today, the main goal of modern researchers is to create a heat-resistant refractory with a flexible structure that ensures its integrity at high temperatures and mechanical loads, which have the ability to form a protective coating layer. In this work, a technological approach has been tested for introducing a vibro-milled modifier (briquette based on a high-alumina component and a titanium-containing additive) into the composition of the raw charge for periclase-spinel refractory in the form of a pre-synthesized product containing crystalline phases of the Al2O3 – TiO2 – FeO system. The basis for the production of periclase-spinel refractories modified with TiO2 is the four-component system MgO – Al2O3 – FeO – TiO2, on the basis of thermodynamic calculations of which the content of individual components of the charge was selected and the operational characteristics were predicted. The interrelation of physical and mechanical properties with the content of individual components in the initial charge warehouses is shown, and the directions of solid-phase processes with their participation are noted. The features of the microstructure of the sample material are noted in relation to the formation of an optimal set of properties. It is shown that the nature of the organization of micropores is favorable for increasing the thermal stability of the material, which complements the phase adaptation mechanism also with the structural effect of damping mechanical stresses during thermal cycling.

SEARCH FOR WAYS OF CONTROLLED MODIFICATION OF CHARACTERISTICS OF FUNCTIONAL UNITS OF ADAPTIVE AIR PURIFICATION SYSTEMS

Information on alkaline coordination nitrates of rare-earth elements of the cerium subgroup - precursors of promising modern multifunctional materials - on the conditions of their formation and existence, the nature of the chemical bond, the composition, structure, shape of the Ln coordination polyhedra, the type of ligand coordination, and the existence of isotypic series in stoichiometry are generalized. composition, structure, characteristic properties. The data obtained (as primary information) is the basis for the detection, identification, and control of the phase state of processing objects in the preparatory stages, the choice of criteria for the compatibility of the components in the formation of single-layer and layered nanostructured oxide composite systems of lanthanides and transition elements for general purposes, with catalytic and photocatalytic activity, coatings self-cleaning with hydrophilic properties; development of various combined methods for their activation and identification of technological functional dependencies; controlled modification of the properties of the obtained target products. To increase the photocatalytic activity of coating samples based on highly dispersed anatase TiO2, a methodology for chemical modification of oxidation centers in their surface layer with heat treatment in contact with thermolysis products of alkaline coordination lanthanide nitrate melts is proposed. An effective test photocatalytic destruction of organic substrates vapors has been discovered using ethanol as an example.Effective activation of the functioning of functional units in the composition of self-adjusting air purification complexes using new photocatalytically active three-layer perovskite-like oxide materials M2Ln2Ti3O10 (M - Li, Na, K; Ln - La, Nd) has been proven. The variability of such methods for creating and modifying the characteristics of polyfunctional coatings is determined by the number and individual properties of representatives of the natural series of lanthanides, alkali metals of the periodic system, the peculiarities of their cooperative behavior in the preparatory technological stages, conditions and methods of activation of formation processes, the nature of the substrate, and other factors.

ASSESSMENT OF THE IMPACT OF TECHNOLOGICAL HEREDITY ON INDICATORS OF RELIABILITY, DURABILITY AND ENVIRONMENTAL SAFETY OF ELEMENTS OF GAS TRANSMISSION SYSTEMS

Modern gas transmission systems are power facilities based on a main pipeline, which is a continuous pipe, along which devices are placed that provide gas pumping at predetermined parameters. Unlike other linear structures, such as roads, railways, the main pipeline throughout the entire period of operation is in a complex stress state under the influence of the internal pressure of the pumped product and functions as a pressure vessel. The operational reliability, durability and environmental safety of gas transmission systems are ensured by various control devices and pipe fittings. The article discusses issues related to predicting the operation of pipe fittings during the operation of the gas transmission system, while ensuring the required reliability, durability and environmental safety. An analysis of the phenomena of technical heredity is given, with the help of which it is possible to determine the causes of deviations in the output parameters of pipe fittings in the process of their manufacture or repair. It has been proved that the main feature of technological heredity is the transfer of a certain technological property from the previous technological operation to subsequent ones, characterized by the transfer coefficient of technological heredity. An indispensable condition for the monotonicity of changes in the transmission coefficient of technological heredity in order to ensure the required quality of manufacture or repair of pipe fittings is revealed. The economic principle of predicting the quality of manufacturing or repair of products is proposed for use, a relationship is found between the initial and output technological properties of pipe fittings, a route is chosen to achieve the required quality of its manufacture or repair, including procurement and finishing technological operations.

MODELING OF PRODUCING PRESSURE IN HETEROGENEOUS OIL-BEARING RESERVOIRS

Numerical modeling of the distribution of the reservoir pressure drop in the vicinity of an operating well was carried out taking into account the inhomogeneous distribution of filtration characteristics (permeability and oil viscosity) in the near and distant zones of the well operation in order to study the practical aspects of filtration in heterogeneous oil-bearing formations based on a combined finite-element-difference method for non-stationary problem of piezoconductivity. The use of the combined finite-element-difference method enables to combine the advantages of the finite-element method and the finite difference method: to model geometrically complex areas, to find the value at any point of the object under study, while the implicit difference scheme. It is shown that the intensity of filtration processes in the vicinity of the operating well depends mainly on the permeability, and, to a lesser extent, on the viscosity of the oil. Moreover, the influence of the permeability of the oil phase in the remote zone (Rd < 5 m) is greater than the effect in the close zone (Rd > 5 m) of the operating well. In the case of low permeability of the oil phase in the vicinity of the existing well, to maintain stable oil production, it is necessary to place an injection well near the production well. Using the method suggested, it is possible to predict the effect of the injection well on the formation pressure distribution in the formation. The scientific novelty of the work lies in the study of the influence of the heterogeneous permeability and oil viscosity distribution on the reservoir pressures distribution around the wells by modeling filtration processes based on a combined finite-element-difference method. The practical significance of the research results comes down to confirming the close relationship between the heterogeneity of the porous medium and the reservoir pressures distribution around an operating producing well. The combined finite-element-difference method used in this work can be used to solve other filtration problems (for example, to calculate the gas saturation of a reservoir, create a method for calculating well flow rates, assess the effect of injection wells on filtration processes).