CFD Analysis of Temperature Distributions in a Slurry Bubble Column with Direct Contact Heat Transfer

Abstract

Slurry bubble column reactors have different applications in the industry due to their advantages. In spite of the simple construction of the slurry bubble column reactors, their scale up analyses are complex due to the effect of various parameters on the hydrodynamic and heat transfer rates in these reactors. Direct-contact heat transfer in slurry bubble columns involves a complex phenomenon of bubble formation and gas motion through the slurry. In this paper, Computational Fluid Dynamics (CFD) simulations are used to investigate the temperature distributions for a direct contact heat transfer in a helium-water-alumina slurry bubble column, where helium gas is injected at 90 o C through a slurry of water at 22 o C and alumina solid particles. This paper studies the effects of superficial gas velocity, static liquid height, and solid particles concentration, on the average temperature of the slurry. In this study, it is assumed that the slurry inside the slurry bubble column is perfectly mixed, and the approaches used to model the slurry bubble column by CFD is 2D plane. From the CFD results, it is found that the average slurry temperature increases by increasing the superficial gas velocity and decreases by increasing the static liquid height and/or the solid concentration at any given superficial gas velocity, but the decrease with the solid concentration is negligible. The results of CFD simulations were compared with experimental data from the literature and show that the profiles of the slurry temperature calculated from CFD models, generally under-predicts the experimental data. The CFD model correctly predicts the experimental effects of static liquid height and solid concentration on average slurry temperature.