Plasma technology - A novel solution for CO2 conversion?
9 May 2017
UAntwerp, Campus Middelheim, A.143 - Middelheimlaan 1 - 2020 Antwerpen (route: UAntwerpen, Campus Middelheim
Organization / co-organization:
Department of Chemistry
PhD defence Ramses Snoeckx - Faculty of Science, Department of Chemistry
CO2 conversion into value-added chemicals and fuels is considered as one of the great challenges of the 21st Century. Due to the limitations of the traditional thermal approaches, several novel technologies are being developed. One promising player in this field, which has received little attention so far, is plasma technology. Its advantages are mild operating conditions, easy upscaling, and gas activation by energetic electrons instead of heat. This allows thermodynamically difficult reactions, like CO2 splitting and dry reforming of methane, to occur with reasonable energy cost.
The aim of this PhD dissertation is to contribute to the central research question, whether plasmas can transform into a valuable technology for the conversion of CO2—preferably into value-added chemicals and/or fuels. Due to the complexity of the entire process, this question cannot be readily answered. Therefore, it is necessary to first seek answers to some other questions related to specific aspects of this process. A lot of research in this domain is still based on assumptions without a good understanding of the ongoing plasma (chemical and physical) processes. As such, there is a clear need for modelling, to better understand and interpret the experimental results and more importantly to improve existing experiments.
By using computer simulations in combination with experiments, this PhD work contributes to the development of several reaction chemistry sets used for a better understanding of the complex plasma chemistry taking place in a dielectric barrier discharge (DBD) and unravelling the underlying chemical reaction pathways. We investigated: (i) the combined conversion of CO2 and CH4, so-called dry reforming of methane (DRM); (ii) the possibilities of artificial photosynthesis using plasma technology by the combined conversion of CO2 with H2O; and (iii) the first steps towards the conversion of CO2 under non-ideal lab-scale situations are taken, where the effect of N2 both as impurity and admixture concentrations on the conversion of CH4 and CO2 is investigated.
Finally a critical assessment of plasma technology for CO2 conversion is made. The four main processes, i.e., pure CO2 splitting, CO2 + CH4 (DRM), CO2 + H2O (artificial photosynthesis), and CO2 + H2 (hydrogenation of CO2) are addressed and compared against the other novel technologies, to draw conclusions and to provide an outlook on the question: plasma technology – a novel solution for CO2 conversion?