Flow behavior and heat transfer in bubbling fluidized-bed with immersed heat exchange tubes for CO2 methanation

This study aims to investigate hydrodynamic and heat transfer characteristics of a BFB reactor with immersed heat exchange tubes for CO2 methanation using a two-dimensional (2D) gas-solid Eulerian computational fluid dynamics (CFD) model. A reaction kinetics model for Ni-based catalyst was coupled with the CFD model. The 2D-CFD model with the Huilin and Gidaspow drag was validated with experimental data for the bed expansion of Geldart B particles according to gas velocity. It was demonstrated that the heat of reaction was effectively removed in the BFB reactor with a 25% heat exchange area and that the reactor maintained isotherm conditions. The CO2 conversion was 92% in the BFB reactor at 400 degrees C and 5 bar. The overall heat transfer coefficient from the bed to the heat exchange tubes was estimated at 114 W/m(2)/K for an inlet gas velocity of 0.13 m/s. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the hydrodynamic and heat transfer characteristics of a BFB reactor with immersed heat exchange tubes for CO2 methanation using a 2D gas-solid Eulerian computational fluid dynamics model. The results showed that the heat of reaction was effectively removed in the reactor and isothermal conditions were maintained. The CO2 conversion rate reached 92% under specific operating conditions.