Plasma catalytic process for CO2 methanation ; Procédé plasma catalytique pour la méthanation du CO2
The limited resources of oil and natural gas, together with an increasing energy demand, forces us to seek more and more efficient and cleaner energy production alternatives. Hydrogen has been recently considered as a promising energy carrier. However, there are several inherent problems to the utilization of H2, from its transportation to its distribution. Transformation of the H2 molecule by fixing into a carbon-containing compound, i.e. CH4, will offer the possibility of using the conventional transportation network. Indeed, the Sabatier reaction, which is highly exothermic, involves the re... Mehr ...
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Dokumenttyp: | doctoralThesis |
Erscheinungsdatum: | 2016 |
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Schlagwörter: | CO2 methanation / Non-thermal plasma / Sabatier reaction / Valorisation du CO2 / Plasmas non-thermiques / Méthanation / Catalyseurs à base de Ni / Réaction de Sabatier / Oxyde mixte Ce/Zr / [CHIM.CATA]Chemical Sciences/Catalysis |
Sprache: | Englisch |
Permalink: | https://search.fid-benelux.de/Record/base-29681089 |
Datenquelle: | BASE; Originalkatalog |
Powered By: | BASE |
Link(s) : | https://tel.archives-ouvertes.fr/tel-01612734 |
The limited resources of oil and natural gas, together with an increasing energy demand, forces us to seek more and more efficient and cleaner energy production alternatives. Hydrogen has been recently considered as a promising energy carrier. However, there are several inherent problems to the utilization of H2, from its transportation to its distribution. Transformation of the H2 molecule by fixing into a carbon-containing compound, i.e. CH4, will offer the possibility of using the conventional transportation network. Indeed, the Sabatier reaction, which is highly exothermic, involves the reaction of carbon dioxide and hydrogen gas in order to produce methane and water. This process, called methanation, represents a feasible approach contributing to the reduction of the CO2 emissions in our atmosphere, through a closed carbon cycle involving the valorization of CO2, i.e. from capture. However, below a temperature of 250 °C, the conversion becomes practically close to 0 %, whereas at higher temperatures, i.e., (>300 ºC), the co-existence of secondary reactions favours the formation of CO and H2. This is the reason why new catalysts and process conditions are continuously being investigated in order to maximize the methane selectivity at low reaction temperatures at atmospheric pressure. Therefore, by using catalysts combined to Dielectric Barrier Discharge plasmas (DBD), the activation of the methanation reaction can be enhanced and overcome the drawbacks of existing conventional processes. Several Ni-containing catalysts were prepared using various ceria-zirconia oxides as supports, with different Ce/Zr ratios. The results obtained in the adiabatic conditions at low temperatures (ranging between 100-150 °C), in the presence of catalysts activated by plasma, are promising. Indeed, the conversion of CO2 to CH4 is about 85 % with a selectivity close to 100 %. The same conversion in the absence of the plasma activation of the catalyst is observed at 350 °C. At low temperatures (120-150 °C) and without plasma, ...