Molten ash slagging moving bed gasification technology is significant for lump coal utilization. Mathematical modeling is essential for a comprehensive understanding of transport and reaction phenomena in a gasifier. In this work, a model based on the impact of bed characteristics was proposed, encompassing: (i) particle fragmentation and agglomeration varied the particle size and bed voidage, (ii) gas channeling weakened the gas-solid heat transfer efficiency and variation of the gas phase temperature, and (iii) molten ash covering coal surface attenuated the gas-solid reaction rate. A good agreement was found between the simulation results of the proposed model and industrial data. Finally, the effects of the operating and model parameters were studied. The results indicated that the steam flow rate had a significant influence on the product gas composition, and the temperatures of gas and solid phases were sensitive to the gas channeling factor.

Fluidized bed reactor is promising for CO methanation owing to its excellent heat transfer performance. The gas flow distribution between the bubble phase and emulsion phase, and the characteristics of heat removal are important for such a solid-catalyzed exothermal reaction in fluidized bed but these are described simplistically in most conventional models. In this work, a novel model contemplating the gas flow distribution influenced by circulation flow and the effect of particle flow on reaction heat removal is proposed. The simulation results of the proposed model and the classic Kunii--Levenspiel model were compared with experimental data of fluidized bed CO methanation. It was shown that the results of the proposed model have better agreement with experimental data. Finally, the investigation for the effect of particle flow was carried out and the results indicated that the particle flow is important to the reaction heat removal.