(550d) Experimental and CFD Simulation Study of Bubble Column Equipped with a Bundle of Heat Exchanging Tubes (Internals) for Fischer-Tropsch (FT) Synthesis

Abbas J. Sultan, Laith S. Sabri, Hayder Al-Naseri, Muthanna H. Al-Dahhan^†

†Multiphase Reactors Engineering and Applications Laboratory (mReal)

† Department of Chemical and Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO 65409-1230. USA

Abstract

The successful design and scale up of the bubble/slurry bubble column reactor are crucially dependent on the proper understanding of their hydrodynamics. Among others hydrodynamics parameters, knowledge of the gas holdup distribution and 3D liquid velocity factors are necessary to design and scale-up of such reactors. Although a large number of published studies on the subject of the bubble column without obstacles. Unfortunately, there is no study in literature accounts for the influence of the vertical internals), which is mimicked to the heat exchanger tubes in the Fischer-Tropsch synthesis (cover 25% of the total cross-sectional area of the column), on the gas holdup distribution and 3D liquid velocity at high superficial gas velocities. Therefore, this study aims for the first time to experimentally investigate and quantify the impact of the dense vertical heat exchanging tubes (internals) size on the time-averaged cross-sectional gas holdup and 3D liquid velocity at the wide range of superficial gas velocities by using gamma-ray computed tomography (CT) and Radioactive Particle Tracking (RPT) Techniques. The second part of this study is to develop 3D Computational Fluid Dynamics (CFD) simulation for bubble column with vertical internals and validate against the experimental data. Experimental and Simulation were performed in 6-inch bubble column with or without internals for air -water system. In this study, two sizes of Plexiglas® internals, covering 25% of the total cross-sectional area (CSA) of a column that simulates those used in Fischer-Tropsch synthesis, were investigated within a wide range of superficial gas velocities (0.05 to 0.45 m/s). The gained knowledge and findings are practical interest in the design, scale-up, and optimization of bubble/slurry bubble columns equipped with vertical internals. Furthermore, this work provided benchmark data to validate and developed the CFD simulation to be able to reproduce hydrodynamic parameters at a different size of columns and configuration of vertical internals as well as operating conditions. At the conference, the results and finding will be presented and discussed.