CHAR GASIFICATION: PARTICLE MODEL COMPARISON IN A STIRRED TANK REACTOR

A simple well mixed model is developed to study the effect of single particle models for the gasification of char in a reactor. Two models, a lumped model and a distributed model, are used to describe the processes in the particle. The model consists of the conservation equations along with the residence time distributions and population balance equations. It is found that neglecting the conversion distribution function in the bed causes considerable differences at high temperatures and large particle sizes. The lumped model is rather insensitive to the mean residence time of the particles and the pressure, compared to the dependence observed in the distributed system. The difference in the design parameters predicted by the models is large and further, the particle size influences these parameters to a greater extent in the distributed system, the lumped system being almost independent of the particle size.