Graphene-based materials GM1 and GM2 have been synthesized by explosive exfoliating two different precursors: graphite oxide and graphite intercalated with chlorine trifluoride respectively. Compositional and structural transformations of the precursors into final graphene-based materials have been followed by using combination of X-ray photoelectron spectroscopy, FTIR and Raman spectroscopy, and Scanning Electron Microscopy. Specific surface area, pore size and electrical conductivity of the synthesized materials have also been measured. Comparative mass spectrometry analysis of the gas co-products emitted during synthesis has revealed that synthesis of GM1 from graphite oxide is more environmentally viable. However, synthesized GM2 materials possess higher electrical conductivity and are characterized by larger size of graphene sheets. We have demonstrated that the graphene nanosheets can be produced from suspensions of the GM1 and GM2 materials in the aqueous solution of a surfactant dodecylbenzenesulfonate. The potential applications areas for the synthesized materials have been discussed.

The article deals with simulation model of collaborative asynchronous generator with short-closed wound rotor and synchronous generator with permanent magnets of comparable capacity as part of an autonomous wind-diesel electric system. This model was developed using a package Matlab Simulink. It is shown the detailed description of the circuit simulation model, as well as all major units included in it. There are results of the simulation of autonomous wind-diesel electric system, which enables the study of transients occurring in the system. This model allows analysis of wind-diesel systems with variable parameters: the magnitude and nature of the load, power of the synchronous and asynchronous generators, fixed and variable speed wind supplied to the wind turbine, which makes it possible to save time in the study of such a system.

At the present time many of the foreign companies spend a lot of efforts for development and production of electric and heat generating power stations based on gas turbine engines. Main feature of such stations is a high speed of turbine driving shaft that allows reducing the size and mass of electric generator. However, typical well-known generators when operating at high speed have large magnetic losses that reduce efficiency of power station. This reason makes a demand for a special high-speed alternator which can operate in turbine engine power station providing starter and generator modes. The article presents the research in choosing the permanent magnet synchronous generator comparing with other types of electric machines for using in power stations based on gas turbine engines. The flowchart of electrical power conversion in the power station is described. Based on presented analysis, a prototype of alternator with radial magnetic gap was built; characteristics of prototype like mechanical torque, output voltage and power, efficiency depending on load are shown.

Today more developers of power supply system pay attention to power stations based on gas turbine engines. These stations have specific requirements to its parts and units; one of it is a high speed of driving shaft of electric generator. Usually for generator of power station the permanent magnet synchronous machines with radial magnetic flux are used. The article describes the possibility to apply a permanent magnet alternator with axial magnetic fux for electric generator of gas turbine power station; there is a brief description of electric machine. The comparison of permanent magnet synchronous machines with radial and axial magnetic flux shows that electric generator with axial magnetic flux provides better efficiency and cost of gas turbine power station. In addition, this solution can give a modularity of alternator parts in serial production in order to build a family of power stations for different power rates.

Progress in the development of technique and methodology of mathematical modelling and numeric computation stimulates a rise of different scientific and engineering software. Meanwhile making a choice of proper software becomes more difficult because of wide possibilities supplied with the different software. This article describes ANSYS Maxwell software, which can be used to analyze different electromechanical systems including permanent magnet synchronous motors and generators which can be used in turbine engine power stations. This software calculates electromagnetic fields using finite element analysis that provides high-precision results. Presented a brief review of major software possibilities used to estimate performance and efficiency of electric generator for high-speed application. All characteristics of examined machine were verified by calculation carried out according to well-known handmade calculation technique that allows recommending ANSYS Maxwell for researchers and engineers interested in having the modern and comfortable tool for electromagnetic calculations.

The article presents the impact results of the microalgae and glycerol fraction wastes of biodiesel production when added cellulose containing raw materials for hydrogen production in a fermentation process conducted by microorganisms association. Production rate of hydrogen increased 1.5 times when the ratio of waste straw and barley microalgae is 8: 2, and hydrogen concentration in the gas phase increased by 5%. The glycerol fraction, which is formed in the production of biodiesel, has the same effect. Simultaneous injection of glycerol and microalgae increased of the hydrogen production rate 2 times.

One of the most important challenges in industry is to reduce consumption of power and materials, and decrease pollution of atmosphere with greenhouse gases and fumes. The purpose of this study was to develop energy-saving technologies and getting heat-resistant protective coatings on the surfaces of high-temperature alloys. The coatings of powder CoCrAlY were deposited to the substrate from a heat-resistant alloy by using a detonation technology. Studies of thermal shock resistance of coatings with two types of cooling mode have been conducted. It is shown that the application technology provides resistance of coatings to thermal shock, which increases the life cycle of the components of heat-resistant alloys.

The paper presents the possibility of increasing the absorption capacity of water through its modifying by fullerenes from the number of compounds that are absorbed from the liquid phase. Furthermore, the paper is concerned with the nature of the absorbing molecules and the method of translation of fullerenes in aqueous solution, which are the factors influencing the absorption capacity.

This paper is devoted to operating experience of heat units, created on the base of catalytic fuel combustion in fluidized bed technology, which allows to mitigate requirements for thermochemical stability of constructional materials and reduce their erosion; to diminish heat losses through apparatus’s walls; to improve start installation and combustion process control; to improve explosion safety of the installation; to reach high values of power loading of the fuel oxidation and heat removal zones; to decrease significantly the design size, weight and metal consumption; to exclude secondary endothermic reactions forming toxic products. Basing on the technology of catalytic fuel combustion, a variety of apparatuses has been designed for the heating and evaporation of liquids, drying and thermal treatment of materials, detoxification of industrial emissions (gaseous, liquid and solid), and so on. Catalytic heat units, such as hot-water boilers for heat and hot water supply of communal and industrial objects, serve as examples of enough wide commercial using of the technology. In the present work results of optimization of construction and exploitation parameters of serial catalytic heat units working with liquid and solid fuels are discussed. The experience of catalytic boilers long operation at the heat supply of communal and industrial objects are generalized. Constructive and exploitation disadvantages of catalytic boilers are established and recommendations upon their removal are given.

The paper deals with the process of hydrogen sulfide containing gases purification based on the reaction of direct oxidation and developed at Boreskov Institute of Catalysis. There are chronological aspects of technology development, and general technological schemes of the modifications technologies implementation of direct catalytic oxidation of hydrogen sulfide in the paper. Based on the results of operation of semi-industrial unit on utilization of hydrogen sulfide acid gas at Bavly oilfield OJSC "Tatneft", the functional principles of the process, the basic hardware, and unit flowsheet are described in details. The main results characterizing the efficiency of the plant and the quality of the main product - elemental sulfur -are adduced. The possibility of the efficient operation of the (proposed) technological method at significant variation in the parameters of the feed gas: hydrogen sulfide and total gas flow is clearly demonstrated. The main units of industrial plant are considered carefully. Based on the results of more than 18 months of industrial run of a process of direct catalytic oxidation of hydrogen sulfide, a comparative analysis with direct prototype of the technology - Process Clause - was carried out. These data clearly illustrate the fact that the developed process is characterized by advanced technical and economic indicators. In conclusion, the toxic impurities contained in the raw coke oven gas of Russian and foreign Coke enterprises are analyzed and compared. Previously described purification processes of coke oven gas are distinguished and classified in terms of physico-chemical principles, and the resulting products. It is shown that coke industry needs to create a modern desulfurization installations, and an additional incentive for the introduction of new environmental technologies is Russia's accession to the WTO, which requires unconditional compliance with international environmental regulations.

Binary catalysts based on platinum and nickel on Vulcan XC-72 carbon carrier were synthesized by magnetronion sputtering in an impulse mode with 50:50 and 70:30 Pt:Ni atomic ratio (metal catalyst content was 38,5 and 39,1% Wt). Their structure and electrochemical characteristics were investigated. Bimetallic nanoparticles have a round or spherical shape. They are uniformly distributed and fixed on the surface of carbon carrier, and their average size ranges from 2,7 to 8 nm. The crystal lattice of these nanoparticles is cubic, and catalysts represent a solid solution of a cluster type. It was shown that binary PtNi catalysts have characteristics which are not worse than characteristics of platinum catalysts (40,2% Wt.). A special feature of these catalysts is their relatively long (14-16 hours) “activation” accompanied by the growth of a current at a constant potential that is caused by partial etching of nickel from the catalyst surface. Additional functionalization of platinum-nickel electrocatalyst based on partial etching of nickel in hydrochloric acid also provides to increase activity of metal nanoparticles.