Partitioning is an important characteristic of the biomass gasification process in a downdraft fixed-bed gasifier, so simulating the partition characteristics has practical guiding significance for revealing the essence of gasification reactions. In this paper, based on the real gasifier, a fluid-solid interfacial reaction method was proposed to simulate heterogeneous reactions based on a holistic gasification model. The partition characteristics, such as the boundary, position, step points, and area of zones, were explored and defined through analyzing the species concentration field, kinetic rate field of reactions, and temperature field. The results indicate that the partition characteristics of kinetic rate distributions are the root cause for zoning in fixed-bed gasification. On the center line of the fixed-bed gasifier, the change nodes of CO concentration tend to be consistent with the nodes of the high kinetic rate of reactions. These results provide a theoretical foundation for the online monitoring of and intervention in biomass gasification.
Tian et al. (Tue,) studied this question.