Numerical simulations of HI decomposition in coated wall membrane reactor and comparison with packed bed configuration

Abstract

HIx decomposition step of the Iodine-Sulphur (IS) thermochemical process for hydrogen production is the most critical step. The Coated Wall Membrane Reactor (CWMR) is an important configuration that can be used for carrying out HI decomposition. The present study uses Computational Fluid Dynamics (CFD) as a tool to assess the performance of a CWMR that ensures higher conversion for HI decomposition, which in turn positively affects the overall thermochemical efficiency of the IS process. The effects of various operating parameters, geometry and properties on conversion are studied. The results show that using a CWMR instead of a coated wall reactor (CWR) leads to significant process intensification by coupling reaction and separation in a single unit and enhancing conversion of the reaction. The operating parameters having significant impact on conversion are identified. Comparison of a CWMR with a Packed Bed Membrane Reactor (PBMR) shows that the PBMR gives higher conversion (at least 6%) than the CWMR for the entire range of parameters considered. For very low space velocity, high membrane permeability and low reactor diameters, conversions in PBMR and CWMR are almost the same.