THERMOCHEMICAL CONVERSION: (CO)GASIFICATION AND HYDROTHERMAL GASIFICATION - Biomass as a Sustainable Energy Source for the Future - page 319

Hybrid FB

BFB (atm./pres.)
CFB (atm.)

Entrained low

Downdraft
ixed bed

Updraft
ixed bed

CFB (pressurized)

0.1 MW 1 MW 10 MW 100 MW 1000 MW

FIGURE 10.7 Different gasification technologies for biomass and their scales.

TABLE 10.3 Some examples of biomass gasification process implementation

Bubbling
fluidized
bed (BFB)

Circulating
fluidized
bed (CFB)

Downdraft
fixed bed

Updraft
fixed bed

Hybrid
fluidized bed

EF

Fluidyne
(NZ)

Babcock and
Wilcox
Vølund
(DK)

Carbona VVBGC

(SE)

MILENA/
ECN (NL)

Shell

Pyroforce
(CH)

Condens
Oy/VTT
(FI)

Enerkem
(CA)

Foster
Wheeler
(USA)

Repotec
(AU)

NUON/
Vattenfall
(NL)

TERI (IN) Bioliq/KIT (DE)

Xylowatt
(CH)

Chemrec (SE)

In each of these reactor types, biomass gasification can be performed, but one should
realize that they are also a compromise between the product gas quality, conversion
efficiency, suitability for handling feedstocks with varying physical and chemical
properties, complexity and scalability of the design, complexity of operation, and
investment costs. In this light, Figure 10.7 illustrates the relevant size ranges of
application of the aforementioned classes of gasifiers. Related to this, Table 10.3 gives
a few examples of current demonstrations and (semi)commercial gasification
activities.

10.3.1 Small-Scale Gasifiers: Fixed and Moving Bed Gasifiers

For comparatively small-scale operation of up to the order of a few MW th , fixed
bed (or moving bed) gasification technology is suitable. There are three basic
types of reactor configuration in this class: downdraft, updraft, and cross-draft