Browsing by Author "Polyanska, Alla"

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Effect of Vapor Treatment on the Caking Properties of Different Coal Types
(MDPI AG, Basel, Switzerland, 2026) Koveria, Andrii; Saik, Pavlo; Polyanska, Alla; Ovcharenko, Alina; Usenko, Andrii Yu.; Pazynich, Yuliya
ENG: Modification of the properties of caking coals through the methods of their treatment is of practical interest, especially in the context of deterioration of the raw material source for coke production and high requirements for the quality of coke. Considering the hydrophobicity of coals and their relatively high porosity, vapor treatment can be an effective method of influencing coal properties. Research on the properties of coal treated with water vapor and crude benzene vapor was conducted using different caking ability methods. Coal moistened to 10%wt. was also investigated for comparison. Four coal samples with varying degrees of coalification, ranging from medium to high rank (Ro = 0.76–1.50%) and characterized by volatile matter (Vdaf = 20.24–37.42%), were investigated. The mechanisms of interaction between coals and water in liquid and vapor form were determined. The results demonstrate that the treatment with water vapor and crude benzene significantly affects the properties of coal A. Specifically, under the influence of water vapor, there is a decrease in the period before the formation of plasticity and an increase in the caking properties of coal A. Coal B and C have good caking ability, so the effect of treatment is less noticeable. The treatment of the coal D leads to an increase in the viscosity of the plastic mass and a decrease in the caking properties. The approaches used in the study of the impact on coal properties can be effectively implemented in production conditions.
How to Achieve the Energy Transition Taking into Account the Efficiency of Energy Resources Consumption
(ACS Publications, 2024) Mykhailyshyn, Khrystyna; Polyanska, Alla; Psyuk, Vladyslav; Antoniuk, Olena
ENG: The study explores the transformation of energy resource consumption centered on energy efficiency within the global energy transition framework. The growing global energy demand, driven by industrialization, urbanization, and rising living standards, has led to increased fossil fuel consumption. This, in turn, contributes to higher greenhouse gas emissions, global warming, and other adverse environmental impacts. The study emphasizes the efforts of developed nations to curb these emissions, particularly by expanding renewable energy use, and notes the declining share of coal and other fossil fuels in national energy balances. The Energy Transition Index (ETI) is introduced as a measure of countries’ progress in advancing the energy transition, including efforts to enhance energy efficiency and mitigate environmental harm. The study also highlights Ukraine’s challenges in energy supply due to military conflict and infrastructure damage, underscoring the critical role of energy efficiency in rebuilding the country's energy system and securing its energy future. Energy efficiency is identified as a key strategy for reducing dependence on fossil fuels, decreasing energy imports, and bolstering the economy’s resilience to external pressures.