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Spectroscopy of VOC degradation by surface discharge catalyzed by TiO2
Veverková, Radka ; Slavíček, Pavel (referee) ; Kozáková, Zdenka (advisor)
Bachelor thesis is focused on the study of degradation of volatile organic compounds in surface discharge catalysed by TiO2. Volatile organic compounds are dangerous both for human beings and the environment. Therefore it is necessary to eliminate volatile organic compounds. Plasma technology is one of the options how to reach their efficient removal. The experiment was carried out in the plasma reactor with electrodes for surface discharge. One or two layers of TiO2 catalyst were deposited on one of the electrodes. Nitrogen was used as a carrier gas and it was mixed with air before entering the reactor. The radiation emitted by the discharge during the degradation of VOC was transmitted via optical fibre to the optical emission spectrometer Jobin Yvon TRIAX 550. Toluene, hexane, cyklohexane and xylene were used as model VOCs. During the experiment the impact of input power on catalysed or non-catalysed degradation of VOC by the discharge has been monitored. Using optical emission spectrometry it is possible to determine some important parameters of surface discharge, such as rotation and vibration temperature. The values were determined for each measurement in the range from 650 to 1050 K for rotation temperature and from 1600 to 1950 K for vibration temperature. The average error of determination was 100 K for rotation temperature and 120 K for vibration temperature. It was found, that the catalyst is without effect on the rotation and vibration temperature. In contrast, change of discharge input power significantly influenced both rotation and vibration temperature. Significantly different values of rotation and vibration temperature were obtained in the presence of particular compound for lower input power, while these values were similar for higher input power. Further, the spectral bands of nitrogen, oxygen and NO were identified from emission spectra. The obtained results may be used as a fundament for further study of volatile organic compounds decomposition in surface discharge.
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Study of volatile hydrocarbon decomposition in non-thermal plasma of surface discharge at atmoapheric pressure
Věrná, Jana ; Rašková, Zuzana (referee) ; Kozáková, Zdenka (advisor)
The main goal of this thesis was to study plasma generated by surface discharge and its application in volatile organic compound destruction. Introduction of this thesis deals with the issue of volatile organic compound. The term of volatile organic compound was defined and explained. Summary of the most important sources of volatile organic compound emissions and possible technics for their elimination was presented. This thesis drew attention on negative aspects of volatile organic compounds on human organism and on the whole environment. The problems of surface discharge and its possible application in various branches are known only few years therefore construction of plasma reactor itself was the first independent step of this work. The plasma reactor was consisted of electrode, which was created from the series of metal stripes each other separated by dielectric barrier. On the surface of the electrode, discharge was regulated and distributed. For the reason of technical limits experiment time was limited up to one minute. The experimental part describes reactor for surface discharge and other parts of apparatus in which degradation volatile organic compound was carried out. Nitrogen was used as carrier gas and it was mixed with air before entering into the reactor. Samples of compounds after degradation process were taken from reactor for the subsequent analysis. Analysis of the products proceeded in a gas chromatogram linked to mass spectrometer. The decomposition products were adsorbed in the SPME filaments or in sorption tubes. The decomposition products were analysed also through the mean of Testo 350 M/XL. This apparatus provided the information on the concentration of small molecules such as CO, H2, NO, NO2 and CxHy Hexane, cyclohexane and xylene were used as VOC examples. Analysis of GC-MS showed decomposition products of hexane, cyclohexane and xylene. The decomposition products were especially various alcohols, ketones, aldehydes and benzene compounds. The apparatus Testo 350 M/XL was unable to detect any CxHy, only large quantity of NO2. This thesis was further focused on possible factors which could have an influence on degradation of compounds, for example input power or different flow of oxygen. It was found that increasing power declined the removal efficiency. The maximum removal efficiency was 87 % for degradation of hexane at the lowest input power. Next part of this thesis was focused on diagnostics of plasma generated in the surface discharge form. The optical emission spectroscopy has been chosen as the best method for plasma characterisation. By this method, various important discharge parameters can be determined, e.g. vibration and rotation temperature. The obtained numeric value of rotation temperature was 840±80 K and vibration temperature was 1880±140 K. The obtained results may be used as a fundament for further study of VOC decomposition in surface discharge.
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Electrical features of surface discharge for organic material decomposition
Budík, Martin ; Zdražil, Vladimír (referee) ; Bartlová, Milada (advisor)
The aim of this semestral work is to describe importance of electric surface discharges for decomposition of organic substances. This will serve to practical measurement of VA characteristic of surface discharge ignition, flow effect and type of portative gas for VA characteristic and moment of ignition of surface discharge. Then measurement of dynamic characteristic of surface discharge in assorted portative gases with diverse kind of flowage and setting of energetic ratios in discharge by means of dynamic characteristics. The main part of this work is dedicated to conditions of discharge ignition, its characteristics in different conditions and another types of discharges.
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Electrical features of surface discharge for organic material decomposition
Budík, Martin ; Zdražil, Vladimír (referee) ; Bartlová, Milada (advisor)
The aim of this semestral work is to describe importance of electric surface discharges for decomposition of organic substances. This will serve to practical measurement of VA characteristic of surface discharge ignition, flow effect and type of portative gas for VA characteristic and moment of ignition of surface discharge. Then measurement of dynamic characteristic of surface discharge in assorted portative gases with diverse kind of flowage and setting of energetic ratios in discharge by means of dynamic characteristics. The main part of this work is dedicated to conditions of discharge ignition, its characteristics in different conditions and another types of discharges.
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Study of volatile hydrocarbon decomposition in non-thermal plasma of surface discharge at atmoapheric pressure
Věrná, Jana ; Rašková, Zuzana (referee) ; Kozáková, Zdenka (advisor)
The main goal of this thesis was to study plasma generated by surface discharge and its application in volatile organic compound destruction. Introduction of this thesis deals with the issue of volatile organic compound. The term of volatile organic compound was defined and explained. Summary of the most important sources of volatile organic compound emissions and possible technics for their elimination was presented. This thesis drew attention on negative aspects of volatile organic compounds on human organism and on the whole environment. The problems of surface discharge and its possible application in various branches are known only few years therefore construction of plasma reactor itself was the first independent step of this work. The plasma reactor was consisted of electrode, which was created from the series of metal stripes each other separated by dielectric barrier. On the surface of the electrode, discharge was regulated and distributed. For the reason of technical limits experiment time was limited up to one minute. The experimental part describes reactor for surface discharge and other parts of apparatus in which degradation volatile organic compound was carried out. Nitrogen was used as carrier gas and it was mixed with air before entering into the reactor. Samples of compounds after degradation process were taken from reactor for the subsequent analysis. Analysis of the products proceeded in a gas chromatogram linked to mass spectrometer. The decomposition products were adsorbed in the SPME filaments or in sorption tubes. The decomposition products were analysed also through the mean of Testo 350 M/XL. This apparatus provided the information on the concentration of small molecules such as CO, H2, NO, NO2 and CxHy Hexane, cyclohexane and xylene were used as VOC examples. Analysis of GC-MS showed decomposition products of hexane, cyclohexane and xylene. The decomposition products were especially various alcohols, ketones, aldehydes and benzene compounds. The apparatus Testo 350 M/XL was unable to detect any CxHy, only large quantity of NO2. This thesis was further focused on possible factors which could have an influence on degradation of compounds, for example input power or different flow of oxygen. It was found that increasing power declined the removal efficiency. The maximum removal efficiency was 87 % for degradation of hexane at the lowest input power. Next part of this thesis was focused on diagnostics of plasma generated in the surface discharge form. The optical emission spectroscopy has been chosen as the best method for plasma characterisation. By this method, various important discharge parameters can be determined, e.g. vibration and rotation temperature. The obtained numeric value of rotation temperature was 840±80 K and vibration temperature was 1880±140 K. The obtained results may be used as a fundament for further study of VOC decomposition in surface discharge.
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Spectroscopy of VOC degradation by surface discharge catalyzed by TiO2
Veverková, Radka ; Slavíček, Pavel (referee) ; Kozáková, Zdenka (advisor)
Bachelor thesis is focused on the study of degradation of volatile organic compounds in surface discharge catalysed by TiO2. Volatile organic compounds are dangerous both for human beings and the environment. Therefore it is necessary to eliminate volatile organic compounds. Plasma technology is one of the options how to reach their efficient removal. The experiment was carried out in the plasma reactor with electrodes for surface discharge. One or two layers of TiO2 catalyst were deposited on one of the electrodes. Nitrogen was used as a carrier gas and it was mixed with air before entering the reactor. The radiation emitted by the discharge during the degradation of VOC was transmitted via optical fibre to the optical emission spectrometer Jobin Yvon TRIAX 550. Toluene, hexane, cyklohexane and xylene were used as model VOCs. During the experiment the impact of input power on catalysed or non-catalysed degradation of VOC by the discharge has been monitored. Using optical emission spectrometry it is possible to determine some important parameters of surface discharge, such as rotation and vibration temperature. The values were determined for each measurement in the range from 650 to 1050 K for rotation temperature and from 1600 to 1950 K for vibration temperature. The average error of determination was 100 K for rotation temperature and 120 K for vibration temperature. It was found, that the catalyst is without effect on the rotation and vibration temperature. In contrast, change of discharge input power significantly influenced both rotation and vibration temperature. Significantly different values of rotation and vibration temperature were obtained in the presence of particular compound for lower input power, while these values were similar for higher input power. Further, the spectral bands of nitrogen, oxygen and NO were identified from emission spectra. The obtained results may be used as a fundament for further study of volatile organic compounds decomposition in surface discharge.
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