(336e) Fast CFD Based Optimization of Coal Moving Bed Gasifier

A coal gasification model has been developed, based on Coarse Grained Discrete Element Model in MFiX. The gasification model has been validated with data from a 200 KWh moving bed gasifier. The validated CFD model is used to optimize the syngas composition of the gasifier for use in a Combined Heat and Power (CHP) process and for use in a Fischer-Tropsch (F-T) process. To accelerate the time to solution of the simulations, a 1-dimensional gasification model was developed to model the transient start up process of the moving bed gasifier. The 1-dimensional model accounts for the drying, pyrolysis, gasification and char combustion during the startup period. Once the gasifier has reached its operating temperature, the results from the 1-dimensional model is used as initial conditions to the 3-dimensional CFD model. This workflow led to achieving the steady state operating condition within 10 minutes of simulation time, using 3-dimensional MFiX-CGDEM.