The September issue of the International Scientific Journal "Alternative Energy and Ecology" presents 15 works of scientists from Uzbekistan, Azerbaijan, USA, Great Britain, Russia and China.

Food security has been an issue for humanity for a long period of time due to seasonal weather conditions and crop yields. Post-harvest losses, seasonal food and agricultural shortages, and global warming are driving forces around the world in developing sustainable solutions. One of the common methods for preserving food and agricultural products is dehydration that is, removing moisture to extend the life of the product, such as fruits and vegetables, etc.

This article proposes an identified method for choosing the shape of a direct-type solar dryer; the shape of a parallelepiped with non-isosceles triangular bases has been selected. The working surfaces, from which solar radiation comes on the surface of the material to be dried, are inclined with respect to the horizon by 38 and 52 degrees, respectively, to the northern latitude of the region.

Concepts were selected, on the basis of which a computational computational method was developed and the geometric dimensions of the elements of a direct type dryer were determined. The formula for the ratio of the dimensions of the height to the length and, accordingly, to the width of the dryer has been established, and a method for determining the dimensions of the flaps has been developed, designed for the flow of air from the environment into the chamber and for the exit of the vapor-air mixture from the inside of the chamber of the dryer into the environment. Such methods of choosing the sizes of the elements of the dryer create an optimal mode of their operation, and also create a natural convection circulation of air inside its chamber.

The paper presents the results of a study of the parameters of photo thermal batteries (PTB) with a change (increase) in the intensity of solar radiation using lateral reflective planes, the effect of cold water temperature, environmental properties and dustiness of the atmosphere on the efficiency of a heat collector based on cellular polycarbonate. It is shown that the photo-thermal battery, in comparison with traditional photovoltaic batteries, gen-erates 1,5-1,6 times more electric energy in the southern regions of the republic, and in the winter season you can get hot water with a temperature of more than 50°C. The studies and tests carried out in the conditions of the city of Termez showed the possibility of obtaining year-round electric energy and hot water in the required amount to create the comfort and coziness of a rural family.

Taking into account that in the Nakhchivan Autonomous Republic of Azerbaijan in summer the energy of the sun's rays reaches 2140 W / per square meter, we conducted experiments to obtain ternary compounds by the method of hydrothermal synthesis. Laboratory studies of the obtained ternary compounds have shown that TlAsS2 and Tl3AsS3 are suitable for the manufacture of solar cells.

Ternary compounds (nanoparticles) of TlAsS2 and Tl3AsS3 have been synthesized under hydrothermal conditions in ethylene glycol medium at the temperature of 413-443 K during 5 hours from thallium acetate, sodium metaarse-nite and thioacetamide as sulfurizing reagent. The thermogravimetric, differential thermal analysis (DTA), electron microprobe and chemical analysis have been carried out. The results showed that the composition of thallium thio- compounds corresponding to the formula TlAsS2 and Tl3AsS3. The results of SEM analysis showed that the obtained TlAsS2 nanoparticles are irregularly shaped. The Tl3AsS3 nanoparticles form nano-crystalline flowers, and their di-mensions vary within the limit of 96.6-213 nm. It is ascertained by X-ray diffraction (XRD) that the parameters of the unit cell a = 12.29Å, b = 11.33Å, c = 6.11Å, β = 104.40, Z = 8 and s. gr. P21/a for the TlAsS2 compound and the pa-rameters of Tl3AsS3 compound a = 12.324Å, c = 9.647Å, Z = 7, s.gr. R3m.

The compound Tl3AsS3 can be applied in the conversion of solar energy into electricity. The use of photocells from Tl3AsS3 compounds during the receipt of electricity is the most effective method.

When using TlAsS2 and Tl3AsS3 compounds on solar converters, which have the property of absorbing the visible part of the solar spectrum well and practically do not emit in the infrared region of the spectrum, significantly in-creases the efficiency of solar converters.

August 6, 2021 President of the International Association for Alternative Energy and Ecology (IAAEE), Head of the Scientific and Technical Center "TATA" and the Institute of Hydrogen Economy, Editor-in-Chief of the International Scientific Journal for Alternative Energy and Ecology (ISJAEE) Alexander Leonidovich Gusev asked 12 questions of the First interview Honorary President of the International Association for Hydrogen Energy, Honorary Editor-in-Chief of the International Journal of Hydrogen Energy (IJHE), Honorary Editor-in-Chief of the International Scientific Journal for Alternative Energy and Ecology (ISJAEE) prof. Dr. Turhan Nejat Veziroglu (T.N. Veziroglu). The questions were announced in a number of mass media and other well-known publications.

The review is devoted to a very urgent problem of utilization of toxic hydrogen sulfide of the Black Sea for the production of hydrogen – a generally recognized environmentally friendly energy carrier of the future and a valuable chemical reagent. The possibilities of the recently discovered method of low-temperature catalytic decomposition of hydrogen sulfide (LTCDHS) for the production of hydrogen and elemental sulfur with the H2S conversion close to 100% are considered. Since this process is carried out at room temperature without the supply of thermal energy from the outside, the main attention is paid to the thermodynamic aspect of the implementation of this chemical transformation. The mechanism of the LTCDHS reaction on sulfide and metal catalysts is considered in the framework of the non-equilibrium thermodynamics of the irreversible processes for open systems, since this process is carried out at the expense of the internal chemical energy of the substrate molecules – hydrogen sulfide. On sulfide catalysts, the irreversible process of H2S decomposition proceeds through the stage of formation of disulfane, H2S2, as a key intermediate, and the reaction products are hydrogen and solid sulfur. The reaction proceeds through a series of successive exothermic stages of dissociation of hydrogen sulfide molecules, in which the entropy of the system decreases due to its scattering (dissipation) into the environment in the form of bound energy TΔS. The remaining part of the free en-ergy is accumulated on the surface of the catalyst and is used for the energy-consuming stage of decomposition of the adsorbed key intermediate. Similarly, a metal catalyst ensures the capture and accumulation of energy from the exothermic processes of adsorption and dissociation of the initial hydrogen sulfide molecules into the atomic adsorbed state of hydrogen and sulfur. The stored energy is used for the chemical transformation of the adsorbed intermediates into the final products of the reaction: molecular hydrogen and diatomic triplet sulfur, followed by their desorption into the gas phase. When hydrogen sulfide is decomposed on metal catalysts at room temperature, along with hydro-gen, a previously unknown diatomic gaseous sulfur is obtained in the ground triplet state, the existence of which is predicted by quantum chemistry. Some properties of triplet sulfur and white globular hexagonal sulfur obtained from its saturated aqueous solutions, which is a previously unknown allotrope of solid sulfur, are considered. The concept of the crucial role of catalysts in the process of LTCDHS is formulated. Depending on the type of catalysts (sulfide or metal), the LTCDHS reaction proceeds via two different routes due to the use of the internal energy of the substrate molecules – hydrogen sulfide. It is concluded that the proposed LTCDHS method is the most acceptable (from the point of view of energy, ecology and economics) technology for the utilization of hydrogen sulfide in the Black Sea to obtain the target product – hydrogen, and a valuable chemical commodity product – elemental sulfur. However, the developed method of LTCDHS goes far beyond the considered problem of the Black Sea. This development can be easily adapted to the existing industrial processes of toxic hydrogen sulfide utilization by the Claus method, when instead of high - temperature, metal- and energy-intensive processes of hydrogen sulfide processing, its catalytic low-temperature decomposition processes will come to obtain the target product - hydrogen. Therefore, hydrogen sulfide as a source of hydrogen production by the LTCDHS method can help to solve the problem of hydrogen energy developing in the near future.

The current trends in energy were described, the main of which is the use of alternative energy sources, especially hydrogen. The most common methods of hydrogen accumulation were proposed: accumulation of compressed gaseous hydrogen in high-pressure tanks; accumulation of liquid hydrogen in cryogenic tanks; storing hydrogen in a chemically bound state; accumulation of gaseous hydrogen in carriers with a high specific surface area. Based on the combination of advantages and disadvantages, the most promising methods of accumulation were selected: storage of liquid hydrogen and storage of hydrogen in carriers with a high specific surface area. The main requirement for materials for hydrogen storage by these methods was revealed – a high specific surface area. Prospects for the development of waste-free low-emission technologies due to the recycling of secondary raw materials and the development of low-temperature technologies for the synthesis of functional and structural materials were substantiated. The applicability of large-scale ash and slag waste from coal-fired thermal power plants as a raw material for obtaining materials by low-temperature technologies was shown. The traditional ways of using ash and slag waste as a raw material, active additive and filler in the production of cements were described. Modern technologies for the production of innovative materials with a unique set of properties were presented, namely carbon nanotubes, silica aerogel and geopolymer materials. The prospect of using geopolymer matrices as a precursor for the synthesis of a number of materials was described; the most promising type of materials was selected – geopolymer foams, which are mainly used as sorbents for purifying liquids and gases or accumulating target products, as well as heat-insulating materials. The possibility of obtaining products of any shape and size on the basis of geopolymer matrices without high-temperature processing was shown. The special efficiency of the development of the technology of porous granules and powders obtained from a geopolymer precursor using various methods was substantiated. The obtained granules can be used in the following hydrogen storage technologies: direct accumulation of hydrogen in porous granules; creation of insulating layers for liquid hydrogen storage units.

For the production of biorenewable hydrogen, the possibility of using pyrolysis of agricultural waste, namely cow dung and stems of weeds Amaranthus retroflexus L. (AR), as well as their mixtures in a ratio of 1:1, 2: 1 and 4:1, was investigated. Thermogravimetric analysis was carried out at a heating rate of 10°C / min in the temperature range from 40°C to 1000°C. It was shown that the thermal decomposition of agricultural waste in an inert environment is characterized by three main stages, the most significant of which is in the temperature range from 145 to 410 C, at which the maximum yield of volatile components occurs. Pyrolysis was carried out at a temperature of 550°C and a heating rate of 10°C / min. During the pyrolysis of a mixture of agricultural waste, the material balance was on aver-age as follows: 36.95% pyrolysis liquid, 24.99% syngas and 38.06% biochar, and the maximum hydrogen concentra-tion in the resulting pyrolysis gas was 21.17% with cow dung to AR ratio of 4:1. With this ratio, the hydrogen yield was 12.1% higher than when using a mixture with a 1: 1 ratio. An increase in the AR fraction enriched the pyrolysis liquid with phenolic compounds. The high content of fixed carbon (47.52%) in biochar is attractive for its use as soil additives. For further research on increasing the yield of gaseous hydrogen from biomass, a scheme of bio-thermochemical processing was proposed, involving a combination of dark fermentation and pyrolysis.

Using a new mathematical model for the hydraulic calculation of pipelines transporting a steam-water geothermal heat carrier, which takes into account the influence of gravity forces on the flow parameters, a study was made of the influence of the location of local resistances on the flow stability. The calculation was carried out using the SWIP-S program for a pipeline with characteristics close to typical values at the Mutnovsky geothermal field, where the larg-est geothermal power plants in Russia are located. The pipeline was divided into 4 sections, 4 options were consid-ered with the placement of all local resistances on the first (from the beginning), second, third and fourth sections The flow stability index was calculated, defined as the partial derivative of the pressure drop in a separate section of the pipeline by mass flow. The pressure drop was also calculated. An insignificant effect of the location of local re-sistances along the pipeline route on its total stability index, as well as on the total pressure drop, was revealed. Based on the calculations of the parameters of pipeline by sections, taking into account the significant differences in the lo-cal index of stability, practical recommendations are given on the location of local resistances: in the case of a high risk of instability at the wellhead, including at low flow rates of geothermal fluid, it is recommended to place them at the beginning of the route, i.e. near the well. Similar recommendations are given if it is necessary to reduce the total pressure drop, given that this parameter will sharply increase in the area where local resistances are focused.

The article discusses the features of the development of systems using renewable energy sources (RES) and hydrogen energy in Russia, which is currently taking place within the framework of the transformation of energy in a low-carbon scenario. An analysis is presented and an assessment of the possible technical and economic potential for the development of new energy technologies in the Russian Federation and the features of the use of hydrogen and renewable energy sources in Russia is presented.

As a renewable, relatively cheap and widely available energy raw material, biomass is now widely used, including various types of waste. Energy use of biomass is known to have no negative impact on the natural balance. It is during the processing of biomass using technologies developed at the Joint Institute for High Temperatures of the Russian Academy of Sciences that the products necessary to solve the problems associated with the transition to carbon-free energy can be obtained. This is the main direction of modernization of energy systems at the present time. The article describes technologies for producing high-quality fuel and hydrogen from biomass: two-stage pyrolytic conversion of various types of organic raw materials into high-quality synthesis gas, processing of associated petroleum gases to produce hydrogen and pyrolytic carbon.

Proposals are presented to compensate for the projected decrease in the state budget of the Russian Federation associated with a reduction in export supplies of fossil hydrocarbon fuels.

The analysis of the operating parameters and available wind resources showed that the energy, generated by the system in some cases, may exceed the consumption abilities of the local energy grid. In such cases usually the system is limiting generated power of wind turbines, leading to underutilization of wind potential and to decrease in the efficiency of the wind power plants used. To improve the use of the wind resource, the wind power plant can be equipped with an extra hydrogen energy storage device, which allows the excess generated power to be used for the electrolysis of water and the production of hydrogen, which in turn can be used to generate electrical energy during periods of peak loads in the electrical grid. To study the processes occurring in the energy system, we developed the Matlab/Simulink mathematical simulation model based on the properties and characteristics of the wind power plant, equipment for the production of hydrogen and other components of the system. Based on the volume of energy production/consumption, the elements are combined into the integral system for modeling the processes of production and use of hydrogen with the wind power plant. Using a simulation model and various data on the wind resource and operating loads in the electrical grid, the parameters of the hydrogen production process and the wind energy utilization factor (wind energy efficiency) were determined for the overall system. The results showed that the implementation of hydrogen energy storage device may significantly increase the efficiency of wind resource usage.

To calculate the parameters of human life support systems for manned aircraft, a method is proposed for determining the disperse composition of peroxide compounds of alkali metals and their mixtures, based on inertial separation of particles. A relationship has been established between the dispersed composition of composite mixtures of alkali metal peroxide compounds based on potassium superoxide, obtained from hydrogen peroxide and potassium hydroxide in a spray reactor with a chemical composition that can be varied during synthesis. On the basis of the calculated estimate, it was proposed to use an alkali-resistant BMD-K glass fiber made of super-thin staple fiber as a filter in life support systems. The efficiency of the filtration system of alkaline aerosols of the smoke-protective hood of the oxy-gen system of the MC 21 and SSJ NEW airliners, proposed on the basis of the calculations carried out according to the original method, was 99.4%. During the research, it was experimentally revealed that the main mass of the retained dust is made up of particles with a size of 10 ÷ 40 μm and their conglomerates, the average size of which is 50 ÷ 70 μm, which fully corresponds to the calculated parameters obtained using the proposed method.

Changes in ecology and climate are associated with the strain of the mechanisms of adaptation of organisms to changing environmental conditions. Trace elements are an integral part of the metabolism and are associated with the processes of vital activity of biological objects. Restructured zinc opens up new horizons for the study and application of trace elements in biology and medicine. The results of the restructured zinc obtained in a new type of reactor (A. N. Frumkin Institute). By prolonged thermodynamic action on the metal melt, chemically pure zinc was obtained, which has a new structure and, consequently, new chemical and physical properties. To assess the chemical activity of zinc, the samples were subjected to oxidation on a thermogravimetric analyzer TGA Q500 InterTech Corporation in a dehumidified air environment in a dynamic mode. The temperature range of measurements was 35-600 °C at a heating rate of 10 °C / min.

There are known vehicles that allow movement in any of the three mutually orthogonal directions – these are airships, planes and helicopters in the atmosphere, rockets in space, submarines in the oceans. A vehicle with absolute cross-country capability (TSAP) with these properties is proposed, which in various design versions can be used for driving on roads (similar to a car), without roads, in the atmosphere at an altitude of several meters to hundreds of meters, on water and under water with high speed and maneuverability.

The proposed solution will reduce the need for highways, especially in the developing countries of Africa and Asia.

The volume of waste heat from cement plants in Uzbekistan has been estimated and it has been found that it is more than 6.8 billion kWh per year.

Methods and devices for converting waste heat into electricity at cement plants, their advantages and disadvantages have been studied. It was found that a thermoelectric generator (TEG) is the most suitable for these purposes. It is shown that the existing methods (ORC, TEG with an efficiency of about 20%) from the waste heat of cement plants can produce up to 1.47 billion kWh of electricity per year, satisfying the needs of these plants for electricity, saving fuel and reducing energy pollution of the environment.

The values of the dimensionless thermoelectric figure of merit ZT = 3.6 and 5-6 achieved in new materials show that TEG is already becoming not only competitive against traditional electromechanical devices, but can also surpass them in durability, reducing the volume of maintenance and repair, cheaply and effectively converting waste heat, saving fuel and contributing to a better environment.

The composition of minerals in Uzbekistan has been studied as raw materials for cheap, safe and sufficiently effective thermoelectric materials. It has been established that there are a number of mineral deposits that are promising for these purposes, but their thermoelectric properties have not been studied.