Due to global climate challenges and the rising concentrations of greenhouse gases in the atmosphere [1, 2] international efforts by scientists, politicians, and industry are focused on reducing CO2 emissions. The use of plasmalysis for CO2 dissociation, especially with the use of microwave plasma, has recently established itself as an innovative approach that is attracting increasing scientific interest due to its potential energy efficiency and environmental friendliness compared to traditional methods [3–5]. To evaluate the plasmalysis process for CO2 splitting, the conversion rate χ and energy efficiency η are used as key parameters, which are specifically analyzed in this study. The research is based on the work of [6], which focuses on the specific energy input (SEI) and the global energy input (GEI). The following article provides a detailed description of the experimental setup and the measurement procedure for the conversion rate. In addition, the evaluation method used to calculate the relevant process parameters is systematically presented. To investigate the influence of different operating parameters on the conversion rate and energy efficiency, specific variations are made and their effects are analyzed and discussed.