Kinetics of CO2 hydrogenation to methanol on Cu/ZnO/ZrO2 based on an extensive dataset

Abstract

The kinetics of CO₂ hydrogenation to methanol over a self-developed Cu/ZnO/ZrO₂ (CZZ) catalyst was studied in a wide range of process conditions. Experiments were performed at industrially relevant pressures (30–60 bar) and temperatures (190–250 °C), as well as H₂ to CO₂ ratios between 1 and 6, addressing the use of hydrogen from renewable energy sources and the use of CO₂ as a C1 raw material in Power-to-X technologies. The CZZ catalyst has shown improved performance and higher stability in CO₂ hydrogenation to methanol in comparison to other Cu/ZnO-based catalysts. A mathematical description of the kinetics is crucial to enable model-based design for the industrial implementation of this catalyst. Therefore, a lumped 6-parameter kinetic model was developed to fit the experimental data, resulting in one of the predictive models with the broadest validity range (experimental database of 500 points) for the CZZ system. This new kinetic model is compared to state-of-the-art literature models with more parameters, and our model performs equally well or even better in terms of sensitivity to process parameters and extrapolability.