Students

Bc. level: 2021 - 2022
Supervisor: Richard Cimerman
Title (en):
Study of the possibilities of using plasma and catalyst in the process of CO2 conversion
Title (sk):
Štúdium možností využitia plazmy a katalyzátora v procese konverzie CO2
Abstract (en):  hide
Carbon dioxide CO2 is a major greenhouse gas produced mainly by fossil fuels combustion. In an effort to slow or stop the rising of CO2 levels in the atmosphere, attention is being paid to different methods of CO2 conversion. One of the promising methods is conversion by plasma and catalyst, the so-called plasma-assisted catalytic conversion. In the theoretical part of this work, several CO2 conversion methods that are currently under study were compared focusing on their advantages and disadvantages. We also presented the theoretical background of plasma generation and fundamentals of plasma catalysis. In the experimental part of this work, plasma as well as plasma-assisted catalytic conversion of CO2 in an atmospheric pressure dielectric barrier discharge generated in a gas mixture of N2 and CO2 was investigated. The utilized plasma reactor was either empty or filled with a packing material (TiO2, MgO or BaTiO3) in a form of pellets. Production of carbon monoxide CO, as the only product of CO2 conversion under the investigated conditions, was analysed by infrared absorption spectroscopy. The electrical characteristics of the reactors (voltage and current waveforms, discharge power) were examined showing that a presence of the packing material in a discharge gap decreases the discharge breakdown voltage and locally amplifies the electric field. These effects were ascribed to dielectric constant and shape of the packing materials. Furthermore, CO2 conversion efficiency (in %), energy efficiency (kWh/g) and energy cost (g/kWh, or mmol/kJ) were evaluated as a function of discharge power. A presence of the packing material in the plasma reactors significantly changed characteristics of the generated discharge what was also reflected in the results of CO2 conversion. The results showed that plasma-assisted catalytic CO2 conversion was more efficient than plasma conversion for all three packing materials used. Both the maximum conversion efficiency (8,4 %) and the maximum energy cost (15,37 g/kWh) were obtained for BaTiO3 packed-bed reactor, although for different values of specific input energy (1200 J/l and 300 J/l, respectively). Second most efficient packing material in terms of conversion efficiency and energy cost was MgO and the least efficient was TiO2.
Abstract (sk)

MSc. level: 2022 - 2024
Supervisor: Richard Cimerman
Title (en):
CO2 conversion by electric discharges and plasma catalysis
Title (sk):
Konverzia CO2 pomocou elektrických výbojov a plazmovej katalýzy