Abstract

An appropriate arrangement of particular zones in the gasifier is of practical importance for the gasification process effectiveness. One of the parameters that affects the optimum reactor operation and has to be taken into account is the speed of bed movement. The transient one-dimensional model describing the heat and mass transfer in the upper section of the biomass fixed bed gasifier that covers the zones of evaporation and pyrolysis, was introduced. To study the effect of packed bed settling resulted from the wood particles’ volume change due to their devolatilization, the simulations for various bed movement speeds were performed. The computation results indicated, as expected, on the different distribution of pyrolysis and drying zones, depending on the speed value. The clear tendency towards the reduction of pyrolysis zone, and on the other hand, towards the expansion of drying zone, with an increasing movement speed was observed.