Dipl. Ing. Matthias Mayerhofer Technische Universität München ...

Biomass Gasification 7
Spouted Bed
It is a fluid bed in which the gasification medium pierces through a thick bead of relatively coarse
particles at high velocity, Figure 4.
Fluidized Bed
Figure 4: Spouted bed (Basu,2010)
The fuel is gasified in a bed of small particles that are fluidized by a suitable gasification medium.
This type of gasifier can be divided into two groups; Bubbling Fluidized Bed (BFB), Figure 5 and
Circulating Bubbling Fluidized Bed (CFB), Figure 6. This gasifier is the most appropriate for biomass
gasification as it achieves excellent heat and mass transfer between the gas and the solid
phases with the best temperature distributions. Its main advantage is that the biomass particles are
uniformly surrounded by the fluidized material so the gasification is taking place uniformly too and
the maximum potential is achieved. The conversion of the feedstock takes place in the bed but
small conversion in gas continues also in the freeboard.
Figure 5: Bubbling Fluidized bed (Basu,2010)