Numerical study of coal gasification in a dual-CFB Plant based on the generalized drag model QC-EMMS

Abstract The gas-solid fluidization and coal gasification reactions in a newly-designed dual circulating fluidized bed (CFB) plant were analyzed by full-loop numerical simulation to provide support for industrial applications. The generalized drag model, QC-EMMS, was used in the Eulerian-Eulerian approach to model the entire coal gasification process in a 60 m high dual-CFB pilot plant with a capacity of 100 tons coal per day. The predicted pressures, temperatures, and syngas compositions are more consistent with field test data compared with the results predicted by using the conventional Gidaspow drag model. The unmeasured solid mass circulation rates were accurately predicted by the QC-EMMS model. The characteristics of gas-solid fluidization and coal gasification were estimated by analyzing the flow and reaction details in the plant. These results show that the QC-EMMS drag model has advantages in simulating the complicated gas-solid flows and reactions in large-scale CFB plants.