Multiphysik-Simulation der Transportprozesse in Sauerstoffpermeatoren mit ungeträgerten und geträgerten Hochtemperaturmembranen [thesis]

Hamid Reza Shahi, Michael Schroeder, Joachim Mayer
Oxygen separation is an important process for CSS (Carbon dioxide Capture and Storage) technology, steel and cement industry, and syngas and power plant applications. There are various methods to separate oxygen. A very famous method is cryogenic method (Linde method), which is however very energy-consuming. It is also possible to separate oxygen by pressure swing adsorption. In this case, oxygen and nitrogen are separated from zeolites due to different adsorption behavior. With this method
more » ... en can be separated with 95% purity. Alternative to these methods, high temperature membranes are used to separate oxygen (OTMs). Oxygen transport membranes (OTMs) are generally mixed oxides with both ionic and electronic conductivity (MIEC, Mixed Ionic and Electronic Conductor). These should also have other high temperature properties, e.g. chemical and mechanical stability. They can selectively transmit oxygen ions. La1-xSrxCo1-yFeyO3-$\delta$ has high oxygen ionic and electronic conductivity and therefore excellent oxygen permeability. Therefore the research focus is placed on the material LSCF6428. Optimum operation is possible when the optimum operating parameters of the dynamic fluids are known. So far, fluid dynamic effects have been neglected in the study of membrane process. In the stationary state, the transport process is examined in a permeation membrane and the transport process into the gas phases is coupled with the transport in the membrane. For the modeling, program COMSOL Multiphysics was used, which is based on finite elements method. The results obtained by simulation were compared and discussed with experimental data. As a second step, a parameter study was carried out at 800°C to understand the influences of the parameters such as volume flow, oxygen partial pressure, distance between the inlets and membrane surfaces, and membrane thickness. It can be shown by this parameter study that the geometry can influence the measured permeation flux and a statement could be made about on the geometric construc [...]
doi:10.18154/rwth-2018-223933 fatcat:cwtbt5lz2rhspcirshltc4y6ie