2Кафедра електротехнічних систем та енергетичного менеджменту, Кіровоградський національний технічний університет, Кіровоград, Україна *Відповідальний автор: e-mail klymvas@ukr.net, tel. +380974862754 ABSTRACT Purpose. To analyze Australian methane hydrate resources, exploration, and production, its current state and future potential.Methods. Analysis of data published in different sources concerned with geological surveys and government reports related to Australian natural gas reserves, production and consumption of gas in Australia. Analysis of theoretical and experimental research into methane hydrates properties and prevention of gas hydrate deposits formation in pipes during production and transportation of natural gas.Findings. The study of gross figures associated with the present state of gas production in Australia testified that enough gas is extracted to meet the current needs. Increase in natural gas consumption in future creates good chances for developing gas production from unconventional deposits, specifically getting methane from gas hydrates deposits. While predicting main trends in the efficient exploration and use of methane hydrates resources it is necessary to consider their possible impact on the environment.Originality. On the basis of the conducted analysis, the current state of methane hydrates research in Australia is examined. For its gas industry, it is critical to estimate their reserves and assess methane extraction from gas hydrates deposits in the near future. Practical implications.The obtained results can be used to evaluate the investment attractiveness of future exploration of methane hydrates resources in Australia.

Purpose. Life cycle assessment (LCA) to investigate environmental impact resulting from the production of separated mixture of rare earth oxides (REO) mined in Australia. Methods. Analytical study of the literature reviews data, measurements and manufacturers' reports, life cycle inventory databases and reasonable estimates of the processes involved in the production of a separated mixture of different REO was performed. To refine the data, was used an approach based on the basis of the matrix and Monte Carlo simulation. To estimate environmental impact from the production of each REO, the method of distributing the environmental impact between different REO was also used. Findings. The obtained results show that the production process of separated REO has a different environmental impact depending upon type of REO: for light REO global warming potential (GWP) is 1.7-3.9 t of CO 2 eq./t of produced REO; a substantially higher impact for medium and heavy REO (GWP is about 90 t of CO 2 eq. per tonne of REO). The major impact comes from production of praseodymium/neodymium (Pr/Nd) oxides (it's about 80% for GWP). The environmental impact from the radioactivity exposure (if waste from the production process is properly managed) shows a relatively low contribution to overall impact on human health (about 0.2%). Originality. The paper pioneered the method of environmental impact distribution, developed by the authors considering the economic value associated with the removal of several co-products from the production processes. The Monte Carlo simulation was used to determine uncertainty of the obtained results during the LCA study. Such approach was allowed more accurately assess different components of the environmental impact resulting from REO production in Australia for the technology described in this paper. Practical implications. The results obtained in the study on the basis of the proposed methodology allows to identify environmental "hot spots" in the production of separated REO and take practical steps to reduce the negative environmental impact of such production.

Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas-hydrated technologies, suitable for energy-efficient transportation of natural gas, the separation of gas mixtures, production and storage of cold, desalinating of seawater, etc. Hydrate formation is one of the main processes of gas-hydrate technological installations. In the article a model is proposed that describes the kinetics of the formation of hydrate in disperse systems, which are characteristic for real conditions of operation of gas-hydrate installations, on the basis of a stochastic approach using Markov chains. An example of numerical calculations is presented on the basis of the proposed model of the dynamics of the total mass of gas hydrates, and changes in the velocity of their formation and size distribution at different values of the nucleation constants and growth rate of the gas hydrates, and results of these calculations are analyzed. It is shown that the rate of formation of hydrate has a maximum value in half the time period of the whole process. The obtained results of the calculations of the dynamics the total mass of gas hydrates are in good agreement with the results of calculations by the equation of kinetics Kolmogorov-Avrami. The proposed model can be applied to the inverse problem: the determination of the nucleation constants and the rate of growth of gas hydrates by the results of the dynamics of the formation of hydrate and the changes in the fractional composition of the generated gas hydrates.

One of the most perspective non-traditional sources of hydrocarbon raw materials and energy is gas hydrates (GH), which stimulates their large-scale study in many laboratories and scientific centers around the world. The interest in the GH is related to the possibility of their industrial application. The use of technologies for storage and transportation of natural gas in the form of GH requires fundamental kinetic studies of the hydration process at atmospheric pressure in the presence of chemical impurities (catalysts, surfactants, etc.). During the research, an increase in the rate of gas hydrates formation was discovered at the expense of activated impurities and composite compounds obtained on their basis, which lead to changes in the hydrochemical and hydrodynamical modes of systems. It was established that the process of GH formation occurs due to the binding of methane macromolecules and other chemical impurities, which contribute to increase the number of moles of gaseous methane, due to the flow of exchange processes between the polymer matrix and water soluble salts, as well as a result of the change in the hydrodynamics of the water system. The purpose of this work is to investigate the effect of polyelectrolytes solutions hydrodynamic properties on the GH formation. We used a number of ionenes based on polymeric quaternary ammonium salts, side aliphatic radicals of different lengths contained in the acyl fragment.

It is suggested that fuel pellets made of composites based on solid plant waste should be considered as stochastic systems that are anisotropic in microvolumes but isotropic in the entire structure, i.e. quasi-isotropic in volume. Based on this hypothesis and the analysis of the known micromechanical models for forecasting physical and mechanical constants of composite materials, the expediency of using the Reuss-Voigt and Hashin-Strickman models to determine the effective elastic coefficients of composite biofuels is substantiated. The results of calculations made on these models for a number of two-component biofuel pellets are given. An experimental evaluation of effective Young's modulus and Poisson's ratio for two-component pellets with "straw + brown coal" composition was carried out. The obtained results of experimentally determined values of coefficients satisfactorily correspond to their calculated values: deviations are up to 26%. The Reuss-Voigt model was used in the calculations because the conditions required for the application of the Hashin-Strickman model are not met for composite pellets consisting of straw and brown coal. The results of the study will be useful in calculating or selecting press equipment for the production of quality fuel pellets from composites based on solid plant waste.