Materials Science Forum Vol. 1164

Abstract: The article analyzes the systems for generation, purification, transportation and storing of gaseous hydrogen as the alternative renewable energy source for ensuring of level of ecological safety of power plants with reciprocation internal combustion engines exploitation process. Purpose of the study is to improve the description of the process of purifying gaseous hydrogen from associated impurities during its production, storage and transportation based on the results of mathematical modeling analysis using improved mathematical apparatus based on modified thermodynamic perturbation theory. Problem of the study is the imperfection of the existing mathematical apparatus for describing the processes of purification of gaseous hydrogen as a commercial product and renewable ecological safe energy carrier using sorption metal hydride technologies based on TiMn_1,5. Idea of the study is to develop a list of recommendations and organizational and technical measures for obtaining ultra-high purity gaseous hydrogen in environmental protection technologies by improving the adequacy of the mathematical description of the processes of its sorption-desorption by intermetallic compounds based on TiMn_1,5. Task of the study is to adapt the mathematical apparatus of the modified thermodynamic perturbation theory to describe the process of selective sorption of hydrogen by metal hydrides of the type TiMn_1,5 from gas mixtures obtained during its production, storage and transportation. Object of the study is sorption processes in metal hydride technologies for the purification of gaseous hydrogen as an alternative fuel and a useful commercial product based on TiMn_1,5. Subject of the study is mathematical description of the course of hydrogen sorption processes by intermetallic compounds of the type TiMn_1,5 when purified from gas impurities. Methods of the study are literature analysis, modified thermodynamic perturbation theory, mathematical modeling. Scientific novelty of results of the study is for the first time, an apparatus for mathematically describing the processes of hydrogen sorption by intermetallic compounds of the type has been suggested TiMn_1,5 from gas mixtures during its production, storage and transportation based on the improvement of the modified thermodynamic perturbation theory. Practical value of results of the study is the improved mathematical apparatus and the results of its application which are suitable for developing a list of recommendations and organizational and technical measures for obtaining ultra-high purity gaseous hydrogen as an ecologicale safe renewable fuel in environmental protection technologies both during the times of armed aggression and during the post-war reconstruction of critical infrastructure and economic potential of our country. The main part of the research is devoted to the adaptation of the mathematical apparatus of the modified perturbation theory to describe the sorption processes of the interaction of hydrogen, which is in the state of a gas mixture, and intermetallic compounds of the type TiMn_1,5. It has been shown that based on sorption metal hydride technologies of the type TiMn_1,5 it is possible to achieve ultra-high purity of gaseous hydrogen as a commercial product when using it as an environmentally safe, renewable type of motor fuel. Mathematical modeling of hydrogen sorption by intermetallic compounds, performed on the basis of the mathematical apparatus of the thermodynamic perturbation theory improved in the study and on the example of the intermetallic hydride TiMn_1,5, based on the application of the lattice gas model for metal hydrides. A list of recommendations and organizational and technical measures has been developed for the implementation of this type of environmental protection technologies in the practice of the units of the State Emergency Service of Ukraine, in particular the operation of fire and emergency rescue equipment with internal combustion piston engines, both during armed aggression and during the post-war reconstruction of critical infrastructure and the economic potential of our country and ensuring the fulfillment of the requirements contained in the Order of the State Emergency Service of Ukraine No. 618 (on the main activity) dated September 20, 2013. «On Approval of the Regulations on the Organization of Environmental Support of the State Emergency Service of Ukraine» and in the historical perspective of achieving the sustainable development goals contained in the Decree of the President of Ukraine No. 722/2019 of September 30, 2019 «About the Goals of Sustainable Development of Ukraine for the Period up to 2030».

Abstract: The carbonized materials structure levels from molecular to macrostructure is analyzed. A study was conducted to find correlations between the granular carbonized materials electrical resistance and other substance physicochemical properties. It is proven theoretically and experimentally that determining the electrical resistance for a granular material, rather than a finely ground sample, is a more informative indicator for reflecting the microstructural features of the material, its reactivity, strength, and clarifying the carbonization conditions. A method is developed for determining the granular materials electrical resistance in the rotating drum interelectrode space, with determination of the indicator value in the cold and hot state for the substance under investigation. An indicator of the granular matter electrical resistance based on the heating time to 670 °C at a drum power supply constant voltage is introduced. Calculated dependencies is obtained for predicting, based on experiment results, some quality indicators for such a carbonized material as metallurgical coke: structural strength, apparent density, reactivity, gasification degree, and electrical resistivity. Better correlations is achieved with these indicators than with the standard electrical resistance on the "micropress" device, which indicates a better reflection of the carbonized materials substance supramolecular structure.

Abstract: New patterns of the complex influence of various parameters on the ignition temperature of magnesium, aluminum and zirconium particles in the products of thermal decomposition of pyrotechnic mixtures based on fluoroplastics have been established. Experimental and statistical models have been developed for the first time to predict the influence of controlled technological parameters on the ignition temperature of metal particles to form a database on the fire-hazardous properties of pyrotechnic products under external thermal effects.

Abstract: The mechanical properties of anodic oxide films of Nb, Ta and Zr were studied by the nanoindentation method. Anomalously high elastic recovery after deformation was observed for oxides with thickness of 20 nm. An analogue of this behavior can be elastic membrane fixed on soft base that does not prevent the membrane from bending. Increase of the oxide thickness to 300 nm reduced the effect associated with the high elasticity of oxide and easy deformation of the soft metal substrate, and was accompanied by an increase in the plastic component of deformation, which is similar to the behavior of ceramic materials with low elastic and significant residual plastic deformation.

Abstract: Experimental studies of some physical properties of paulownia wood and identifies differences in comparison with other popular species are presented. In particular, the regularities of hydration and dehydration processes were investigated. Based on the results obtained, reliable data on the hygroscopic properties of paulownia were obtained for the first time. It was found that the hydration rapidity of paulownia (V_pl = 1.493) exceeds the similar rate of pine (V_pn = 1.1313) at a temperature of 20 °C. Changing the temperature of the liquid in which the wood is modified leads to an increase in the impregnation rapidity and, therefore, increases the productivity of the process. The dehydration rapidity of both species is almost the same (k = –0.002), which allows them to be dried simultaneously in the same chamber, optimizing production logistics. The dependence of liquid absorption on concentration was investigated. It has been found that a higher concentration outside causes a greater diffusion flux into the sample, while a higher concentration inside leads to a decrease in the sample weight. During the hydration stage, the weight of paulownia samples increased by 4 times, and pine samples – by 2.5 times. A two-stage kinetic model of wood hydration has been developed, which adequately describes the dynamics of the process. The resulting S-shaped curve clearly characterizes the features of the kinetics processes with saturation. Verification showed a high correlation – 85 % – for hydration and over 90 % for dehydration, which allows for accurate modeling and prediction of the technological processes of wood impregnation and drying.

Abstract: The study assesses the efficiency of the heat-insulating coating on the surface of the PSV-250 steam-water heater, valves, and pipelines. The efficiency was evaluated using a non-contact method as part of a comprehensive study of heat losses through thermal imaging. During the inspection of the heater’s thermal condition, elements with surface temperatures ranging from +60 °C to +224.5 °C were identified, which poses a hazard from an occupational safety perspective. To prevent burns to maintenance personnel and reduce heat losses that lower the efficiency of thermal equipment, these surfaces must be insulated. To address the identified issues, it is recommended to install special removable insulation or apply a thermal insulation coating based on a liquid ceramic composite material.