Experiment and numerical analysis of catalytic CO2 methanation in bubbling fluidized bed reactor

This study experimentally and numerically investigated the hydrodynamics, reaction kinetics, and heat transfer of a bench-scale bubbling fluidized bed (BFB) reactor for CO2 methanation. A three-dimensional gas-solid Eulerian computational fluid dynamics (CFD) model coupled with a modified Syamlal-O'Brien drag model and reaction kinetics for Ni-based catalysts was developed. The CFD model was validated against experimental data for pressure, temperature, and gas composition at 1 bar and an inlet flow rate of 2 L/min with an inlet N-2 content of 77.5%. The axial pressure drop, solid volume fraction, temperature, gas composition, and bed-to-wall heat transfer coefficient (HTC) were compared for four inlet N-2 contents: 77.5%, 50%, 25%, and 0%. As the inlet N-2 content decreased, the mean bed temperature increased from 340 to 456 degrees C, the gas volume decreased owing to the reaction, the fluidizing number (ug/umf) decreased from 4.1 to 3.5, and the solid holdup increased. Consequently, the HTC increased from 327 to 386 W/m(2)/K. This study identified successfully the effects of hydrodynamics and reaction kinetics on HTC in the BFB for CO2 methanation.

Automated summary

This study investigated the hydrodynamics, reaction kinetics, and heat transfer of a bench-scale bubbling fluidized bed reactor for CO2 methanation. The study successfully identified the effects of hydrodynamics and reaction kinetics on heat transfer coefficient in the reactor.