Detailed Chemical Kinetics of Closed Carbon Cycle Fuel Oxidation in Super Critical Carbon Dioxide

• Applicant: Professor Dr.-Ing. Alexander Heufer
• Subject Area: Energy Process Engineering
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 562309324

This research proposal explores the detailed chemical kinetics of closed carbon cycle fuel oxidation in supercritical carbon dioxide (CO2), with the aim of advancing sustainable energy solutions. It investigates the combustion of methane, methanol, and dimethyl ether within the context of the Allam cycle - an innovative oxy-fuel process with near-zero CO2 emissions. This cycle integrates oxygen and supercritical CO2 for combustion, recycling exhaust gases by condensing water and capturing CO2 for reuse in subsequent combustion processes. The urgency of transitioning from fossil fuels to sustainable energy sources serves as the foundation for this study. The focus is on understanding combustion chemistry under supercritical conditions, particularly the real gas effects that have been underexplored in conventional combustion studies. By addressing these gaps, the research seeks to enhance the feasibility of closed carbon cycle technologies. Combustion processes in supercritical CO2 are examined using a combination of theoretical, numerical, and experimental methods. The study builds on established ideal gas combustion principles but emphasizes the unique challenges of supercritical environments, such as high-pressure conditions and real gas effects. Key objectives include measuring ignition delay times for methane, methanol, and dimethyl ether using shock tubes and rapid compression machines, conducting quantum mechanical calculations to predict thermodynamic and kinetic properties, and developing detailed chemical kinetic models tailored to the supercritical CO2 context. To achieve these goals, the research is structured into three work packages (WPs): WP1: Measurement of ignition delay times for the selected fuels in supercritical CO2. WP2: Ab initio calculations to determine thermodynamic properties and rate coefficients under supercritical conditions. WP3: Development of kinetic models for the target fuels, including adaptations from ideal gas combustion models. By delivering an in-depth understanding of fuel combustion in supercritical CO2, the research contributes to the advancement of nearly CO2-neutral combustion technologies, thereby supporting the global shift toward a sustainable energy economy.

• DFG Programme: Research Grants