Improved CO₂ Capture in Gas-Liquid Contactors
Background:
Gas-liquid contactors are a central technology in the chemical industry, widely used for reaction and separation processes such as carbon capture. Improving the efficiency of these systems is particularly important for reducing CO₂ emissions from industrial and combustion processes. In such devices, mass and heat transfer often occur in thin liquid films, where flow behavior strongly influences absorption performance. It is well known that wavy or destabilized liquid films can significantly enhance transfer processes compared to smooth flows, but the underlying mechanisms are not yet fully understood. It is important to better understand and exploit these mechanisms for more efficient CO₂ capture. In particular, micro-scale mixing phenomena at the gas–liquid interface are expected to improve absorption rates. However, the interaction between hydrodynamics (film flow behavior) and reaction/absorption kinetics is complex and only partially studied. The project seeks to close this knowledge gap by systematically investigating how structured surfaces and process parameters can intensify interfacial transport and ultimately improve reactor efficiency.
Project:
The work focuses on improving CO₂ absorption in falling film reactors through targeted modification of surface structures. By introducing defined surface geometries, interfacial instabilities and mixing effects are intensified, leading to increased film waviness and the formation of internal recirculation zones that promote mass transfer. A central objective is to establish quantitative relationships between hydrodynamic behavior and absorption performance, enabling the identification of optimal surface configurations for enhanced efficiency. To achieve this, a combination of experimental and numerical tools is used. Experimentally, custom-built test rigs (falling film absorbers) and advanced optical diagnostics, such as high-speed imaging, chromatic confocal sensors, and light absorption techniques, are applied to measure film thickness, waviness, and absorption rates. Numerically, simulations based on Smoothed Particle Hydrodynamics (SPH) as well as volume-of-fluids methods are developed/applied to study flow dynamics and reactive transport phenomena at high resolution. Together, these complementary approaches enable a detailed investigation of flow structures, interfacial phenomena, and their impact on CO₂ absorption efficiency.
Contact: Andrea Düll, Thomas Häber, Prof. Dr. Olaf Deutschmann
Cooperation: - Dr. Marion Börnhorst, Reaction Engineering and Catalysis Group, TU Dortmund University - Dr. Cihan Ates, Institute of Thermal Turbomachinery (ITS)
Funding: Friedrich und Elisabeth Boysen-Stiftung (Boy-165)
Selected publications:
A. Düll, J. Lehmann, M. Börnhorst, C. Ateş, T. Häber, O. Deutschmann, Spatio-temporal characterization of the three-dimensional wave dynamics in falling film flows over rectangular corrugations, Exp Fluids 66 (2025) 71. https://doi.org/10.1007/s00348-025-03978-2.
A. Düll, A. Happ, J. Buchmüller, C. Ateş, M. Börnhorst, T. Häber, O. Deutschmann, How structure-induced resonance waves intensify mass transfer in a falling film absorber for CO₂ capture, Chemical Engineering Journal 523 (2025) 168228. https://doi.org/10.1016/j.cej.2025.168228.
A. Düll, A. Cros-Le Lagadec, J. Buchmüller, T. Häber, C. Ates̗, M. Börnhorst, Intensifying interfacial oscillations in falling film flows over rectangular corrugations, Physics of Fluids 36 (2024) 092107. https://doi.org/10.1063/5.0222760.
Funding:
