Effect of Superficial Gas Velocity on Bubbling Fluidized Bed Behaviour in a Biomass Gasifier

Abstract

This study investigates the behaviour of bubbling fluidized beds in biomass gasification processes based on the variation of superficial gas velocity at different temperatures and air flowrates. In the paper, the operating window is defined as the gas velocity between the minimum fluidization and slugging velocities, which are computed using the correlations in the literature. The analysis shows that the operating gas velocity depends on the amount of char accumulated in the bed. An increase in the char accumulation results in higher minimum fluidization and slugging velocities of the bed mixture. This therefore suggests that the gas velocity ratio required to achieve the desired operating fluidized bed regime is higher when the biomass accumulation is considered.