(671g) Modeling of Catalytic Fixed-Bed Reactors: Comparison of 1D/2D Porous Media and 3D Particle-Resolved Simulations

Fixed bed reactors are the workhorse of the chemical process industry and thus packed bed reactor analysis is of great importance to the chemical process industry. Whilst Particle Resolved CFD (PRCFD) can be comprehensive and important in some circumstances (like narrow-diameter tubes), the computational expense can be too intensive (as measured by time and cost) to practically model industrial reactors. To address these challenges, DETCHEM [1] PBR (DETailled CHEMistry Packed Bed Reactor, or PBR) was developed to simulate fixed bed reactors in one-dimension. Meanwhile, DUO, (DETCHEM und OpenFOAM [2]) can be used for PRCFD [3], allowing for comparisons between PBR (1D) vs DUO PRCFD (3D).

Several validation tests were performed comparing 1D vs. 3D PRCFD. Catalytic Partial Oxidation (CPOX) and Dry Reforming of Methane (DRM) at three different tube to particle ratios N of 1.1, 2, and 7, and three different particle Reynolds numbers (Re_p = 29, 145, 290 and 1450) have been investigated. Results were generally good, demonstrating that for these reactions and conditions a 1D model can achieve the same results as PRCFD in a fraction of the time (seconds vs. hours).

DUO can also simulate porous media [2] using different energy model assumptions: i.e., separate (aka heterogeneous or non-equilibrium) or combined (aka homogeneous or equilibrium) energy equations for the fluid and solid phases. Under tested conditions, PBR-1D, DUO-2D (both heterogenous and homogeneous energy models), and DUO-3D (PRCFD, Fig. 1) produced similar results for CPOX and DRM cases.

[1] DETCHEM v3.0 2024. omegadot software & consulting, GmbH. www.omegadot.software .

[2] OpenFOAM v11, The Open Source CFD Toolbox, www.openfoam.org .

[3] E. Daymo, M. Hettel, O. Deutschmann, G. Wehinger. Chem. Eng. Sci. 250 (2022) 117408.

[4] E.A. Daymo, A.L. Tonkovich, M Hettel, A. Shirsath, 1D and 2D porous media fixed bed reactor simulations with DUO. Meccanica (2024). https://doi.org/10.1007/s11012-024-01764-8