Mathematical modeling for bubbling fluidized bed CO-methanation reactor incorporating the effect of circulation and particle flows

Abstract

Fluidized bed reactor is promising for CO methanation owing to its excellent heat transfer performance. The gas flow distribution between bubble and emulsion phases, and the characteristics of heat removal are significant for such a solid-catalyzed exothermal reaction in fluidized bed but these are described simplistically in most conventional models. In this work, a two-phase model contemplating: (i) the effect of circulation flow on gas flow distribution, (ii) the effect of particle flow on reaction heat removal, was proposed. The proposed model was validated by comparison with experimental data of the fluidized bed CO-methanation reactor. Meanwhile, simulation results of the proposed model and Kunii–Levenspiel model were compared. Finally, sensitivity analysis of important parameters was carried out. The results indicate that: (i) particle flow has more significance than circulation flow; (ii) the effect of bubble size is limited within bubbling region and bed-wall heat transfer has obvious influence in freeboard.