Entrained-bed coal gasification modelling. Interim report

A mathematical model has been developed to simulate the Texaco Downflow Entrained-Bed Pilot Plant Gasifier using coal liquefaction residues and coal-water slurries as feedstocks. The entrained-bed gasifier was conceptually divided into three zones: the Pyrolysis and Volatile Combustion Zone, the Gasification and Combustion Zone, and the Gasification Zone. The gas phase was assumed to be completely mixed at the entrance region followed by a region approximating plug flow. The solid phase was assumed to be a plug flow throughout the reactor. Temperature and concentration profiles along the reactor were obtained by solving the material and energy balances and taking into consideration the gasification kinetics, the transport rates and the hydrodynamics of the gasifier. The results of computation from the proposed model were compared with the experimental data. Sensitivity of the parameters used in the model was tested and optimum operating conditions were searched to provide a better understanding of the performance under various operating conditions utilizing the model.