Experimental verification of 2-dimensional computational fluid dynamics modeling of supercritical fluids Fischer Tropsch reactor bed

Abstract

Abstract A 2-D Computational Fluid Dynamics (CFD) model of a Packed Bed (PB) Fischer Tropsch (FT) reactor was developed using a non-conventional Supercritical Fluid (SCF) as reaction media. The model was used to study the effect of using SCF-FT reactor bed in alleviating hot spot formation, typically occurring in conventional Gas Phase FT reactors (GP-FT). The potential of scaling-up a typical industrial 1.5-inch diameter reactor bed to a larger tube diameter (up to 4″ ID) was studied as a first step towards process intensification of the FT technology. The high fidelity 2-D model developed in this work was built on experimental data generated at a variety of FT operating conditions both in conventional GP-FT and in SCF-FT reactor bed. Results showed that the maximum temperature rise in SCF-FT for a 4″ ID bed was just 15 K compared to ˜800 K in GP-FT bed for 15 % C o / γ - A l 2 O 3 based catalyst at 500 GHSV and 518.15 K. The enhancement in thermal performance in SCF-FT reactor bed is attributed to the high thermal capacity of SCF media (˜2500 J/kg/K) compared to GP (˜1300 J/kg/K), which resulted in the elimination of hotspot formation. These results provide the first evidence for the application of SCF-FT in larger tube reactor beds while overcoming issues resulting from hotspot formation.