Liquid and Solids Phase Backmixing in a Bubble and Slurry Bubble Column using a Virtual Tracer Response Methodology based on the Trajectory Data of the Radioactive Particle Tracking (RPT) Technique
Virtual tracer response methodology developed based on the trajectory data of the computer aided radioactive particle tracking (CARPT) technique was demonstrated. The demonstrated virtual tracer technique has advantages of non-invasiveness, near perfect injection/sampling, and flexibility in choosing the sampling/injection boundaries in a specific spatial pattern. With the developed virtual tracer technique, liquid and solids backmixing were investigated at the conditions mimicking Fischer-Tropsch synthesis. Experiments were conducted at different pressure, solids loading, and superficial gas velocity. The axial dispersion model (ADM) and recirculation and cross flow dispersion (RCFD) models were used to model the liquid mixing. Transient sedimentation dispersion model (SDM) was used to model the solids mixing. It was found that the measured axial dispersion coefficient (Dl) in the ADM model increases with increase in the pressure. The increase of dispersion coefficient was explained with the experimental values of mean axial diffusivity and mean recirculation velocity. Axial dispersion coefficients (Dz,uDz,d) in the RCFD model (compartment model) were apparently lower than the Dl, due to the decoupling of global recirculation from the dispersion coefficients in the RCFD. Further, it was found that the dispersion coefficients in the RCFD model follow the trend of the axial eddy diffusivity with change in the operating conditions revealing the dominance of the turbulence in the upflow and downflow compartments. From the solids backmixing study, axial dispersion coefficient (Ds) of solids was found to increase with increase in the solids loading, pressure, and superficial gas velocity at the studied conditions.
L. Han et al., "Liquid and Solids Phase Backmixing in a Bubble and Slurry Bubble Column using a Virtual Tracer Response Methodology based on the Trajectory Data of the Radioactive Particle Tracking (RPT) Technique," Canadian Journal of Chemical Engineering, Wiley, May 2021.
The definitive version is available at https://doi.org/10.1002/cjce.24187
Chemical and Biochemical Engineering
Center for High Performance Computing Research
Early View (Online Version of Record before inclusion in an issue)
Keywords and Phrases
Backmixing; Dispersion; High Pressure Slurry Bubble Column; Virtual Tracer
International Standard Serial Number (ISSN)
Article - Journal
© 2021 Canadian Society for Chemical Engineering, All rights reserved.
11 May 2021