Chemistry Reference
In-Depth Information
Fig. 3 Proposed strategies for production of
fuels from biomass (Adapted from
Huber et al.
28
).
Table 1 Typical product yields on dry wood basis obtained by different wood pyrolysis
technlogies.
*
Process
Conditions
Liquid (%)
Char (%)
Gas (%)
Fast pyrolysis
Moderate temperature (
B
773 K),
short residence time
75
12
13
Low temperature (
o
773 K),
very long residence time
Carbonization
30
35
35
Gasification
High temperature (W 773 K),
long residence time
5
10
85
*Data from Bridgwater.
35
biomass type. Some plant materials, such as cane sugar and corn, are
easily converted into their monomer units. For more details about the
selective and energy ecient conversion of biomass into monomer units
by hydrolysis, and subsequently selective conversion of monomer units
into fuels or platform chemicals we refer to the literature.
13,18
Production of liquids (often referred to as bio-oil) by liquefaction and
pyrolysis involves thermo(chemical) treatment of biomass. The most
promising advantage of this process is that the highest yield of liquid can
be obtained. Furthermore, this process is relatively simple, usually re-
quiring only one reactor.
Table 1 compares the yields of liquid, char, and gas for different pyr-
olysis technologies. Pyrolysis, and especially fast pyrolysis, produces the
highest yield of liquid. Virtually any type of biomass is compatible with
pyrolysis, ranging from cotton straw and stalk to wood and waste prod-
ucts.
36-38
Although the pyrolysis process is mainly tested in the lab-scale,
bench-scale fluidized-bed fast pyrolysis of peanut shell in industry for
