Fluidized Bed Combustion of Coal, Renewable Fuels, and Waste: Current Status and Developments - Novel Combustion Concepts for Sustainable Energy Development - page 232

4 Novel Concepts

4.1 Gasi cation of Biomass Using Fluidized Bed

—

Technology

Fluidized bed technology is an excellent tool for use in biomass gasi cation.

Because of its very good transportation of the bed material, the fl fluidized bed can be

divided into two zones: A gasi ed and a

combustion zone where the residual biomass char is burned and heat is produced
from the gasi

cation zone where the biomass is gasi

cation of the biomass. The hot bed material is then transported into

the gasi cation zone and the two zones are coupled. Steam is used as the fl fluidizing

and gasi cation agent.

The gas produced is rich in H 2 and CO besides CO 2 and CH 4 and can be used for a
range of applications such as Fischer-Tropsch for biodiesel or biofuel production, or
synthesis gas which can be used in gas engines for electricity production (see Fig. 5 ).

4.2 Oxyfuel Combustion Using Fluidized Bed Technology

—

In the European Union project Flexi Burn CFB (Tourunen 2013 ), it was demon-
strated that a

fluidized bed is able to operate successfully in the oxyfuel combustion
mode. In oxyfuel combustion, the fuel is not burned with air but in a gas which is

fl

Fig. 5 Concept of the fl fluidized bed gasifier in G ü ssing, Austria, using biomass (Hofbauer 2002 )