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Temperature influence on ozone generation and decomposition on solid surfaces
Krejsková, Eliška ; Dřímal,, Jiří (referee) ; Kozáková, Zdenka (advisor)
This master’s thesis is focused on a study of temperature influence on ozone generation and decomposition by chosen solid surfaces. Ozone is unstable gas that is decomposed spontaneously. This decomposition can be accelerated by various factors such as increase in temperature or reaction with other substances. The aim of this study is to determinate how fast the ozone decomposition proceeds at different temperatures and how the homogenous decomposition of ozone is accelerated by heterogeneous processes on the walls of solid materials. Currently in practise ozone is used in many areas and the finding of the rate of its decomposition can help to increase efficiency of its production and subsequent specific applications. In the theoretical part of the thesis, these points are described: important properties of ozone, possibilities of its utilization, the ozone generation, some methods of determination of the ozone concentration, ozone relationship to various solid surfaces and present theoretical knowledge about the effect of temperature on the ozone generation and decomposition. In the experimental part, the rate of the ozone decomposition in reaction tubes made of copper and iron of two different surface to volume ratios was investigated at temperatures of 10, 25, 40, 55, 70 and 85 °C. Ozone generated from oxygen was closed in the reaction tube and the decrease of its concentration during the time was observed by absorption spectroscopy. From obtained exponential dependencies, the rate constants at different conditions of this experiment were evaluated. The rate of ozone decomposition significantly increased with higher temperature. The fastest ozone decomposition took place in the iron tube of larger inner diameter (8 mm).
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Study of ozone decomposition on solid surfaces
Krejsková, Eliška ; Stančík, Jiří (referee) ; Kozáková, Zdenka (advisor)
This bachelor’s thesis is focused on the study of ozone decomposition which occurs during its contact with solid surfaces. The aim is to find out which material causes the lowest ozone decomposition and that is why it is the most suitable material for pipelines used for ozone transportation from a place of production to a place of application. In the theoretical part important properties of ozone, possibilities of its production, methods of ozone determination and relation of ozone to different solid surfaces were described. In the experimental part there was investigated how much ozone is decomposed by five commonly available metal materials (stainless steel, yellow brass, copper, aluminium and iron). Measurements were realized in the glass tube (Liebig condenser). Hollow pipes made of particular material were inserted into this tube. Ozone passed through this glass tube and ozone concentration was determined on its output by two methods: the iodometric titration and spectrophotometry. Several series were measured and compared by different set-up conditions like reaction time, experimental parameters (flow rate of air, input power of the ozone generator) and two types of gas – technical and synthetic air (because moisture contained in technical air can cause ozone decomposition) were used. The most suitable materials – stainless steel and aluminium were determined according to gained results.
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Temperature influence on ozone generation and decomposition on solid surfaces
Krejsková, Eliška ; Dřímal,, Jiří (referee) ; Kozáková, Zdenka (advisor)
This master’s thesis is focused on a study of temperature influence on ozone generation and decomposition by chosen solid surfaces. Ozone is unstable gas that is decomposed spontaneously. This decomposition can be accelerated by various factors such as increase in temperature or reaction with other substances. The aim of this study is to determinate how fast the ozone decomposition proceeds at different temperatures and how the homogenous decomposition of ozone is accelerated by heterogeneous processes on the walls of solid materials. Currently in practise ozone is used in many areas and the finding of the rate of its decomposition can help to increase efficiency of its production and subsequent specific applications. In the theoretical part of the thesis, these points are described: important properties of ozone, possibilities of its utilization, the ozone generation, some methods of determination of the ozone concentration, ozone relationship to various solid surfaces and present theoretical knowledge about the effect of temperature on the ozone generation and decomposition. In the experimental part, the rate of the ozone decomposition in reaction tubes made of copper and iron of two different surface to volume ratios was investigated at temperatures of 10, 25, 40, 55, 70 and 85 °C. Ozone generated from oxygen was closed in the reaction tube and the decrease of its concentration during the time was observed by absorption spectroscopy. From obtained exponential dependencies, the rate constants at different conditions of this experiment were evaluated. The rate of ozone decomposition significantly increased with higher temperature. The fastest ozone decomposition took place in the iron tube of larger inner diameter (8 mm).
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Study of ozone decomposition on solid surfaces
Krejsková, Eliška ; Stančík, Jiří (referee) ; Kozáková, Zdenka (advisor)
This bachelor’s thesis is focused on the study of ozone decomposition which occurs during its contact with solid surfaces. The aim is to find out which material causes the lowest ozone decomposition and that is why it is the most suitable material for pipelines used for ozone transportation from a place of production to a place of application. In the theoretical part important properties of ozone, possibilities of its production, methods of ozone determination and relation of ozone to different solid surfaces were described. In the experimental part there was investigated how much ozone is decomposed by five commonly available metal materials (stainless steel, yellow brass, copper, aluminium and iron). Measurements were realized in the glass tube (Liebig condenser). Hollow pipes made of particular material were inserted into this tube. Ozone passed through this glass tube and ozone concentration was determined on its output by two methods: the iodometric titration and spectrophotometry. Several series were measured and compared by different set-up conditions like reaction time, experimental parameters (flow rate of air, input power of the ozone generator) and two types of gas – technical and synthetic air (because moisture contained in technical air can cause ozone decomposition) were used. The most suitable materials – stainless steel and aluminium were determined according to gained results.
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