24
sustainability credentials. In addition, the hydrogen yields can be maximized by
injection of steam (which can be TCR aqueous phase) into the TCR system, which
promotes a water gas shift reaction [129, 140]. This is in contrast to fast pyrolysis
that needs an outside source of H 2 to improve the bio-oil properties [147].
The Van Krevelen diagram represents the O/C and H/C ratios for varied technologies (Fig. 10). The O/C and H/C of bio-oil from the TCR of woody biomass
were 0.19 and 1.27, respectively [145, 146]. However, the bio-oil from fast pyrolysis of woody biomass has considerably higher values of O/C (0.56) and H/C (1.56)
than TCR results [57, 82]. Additionally, the O/C and H/C of hydrotreated bio-oils
from fast pyrolysis of woody biomass over Ni-based catalysts are slightly different
from the TCR values [148]. Therefore, TCR displayed significant enhancement of
bio-oil properties and stability characteristics.
7 Upgrading of Bio-oil
Fast pyrolysis bio-oils have a lot of drawbacks such as thermal instability, high
oxygen content and high viscosity and corrosiveness. Therefore, fast pyrolysis biooil upgrading should be performed to decrease the oxygen content and acidity
before its application [57, 80]. There are different methods to upgrade bio-oil,
which are emulsification, filtration, polar solvent, catalytic and TCR cracking,
hydrotreatment, aqueous phase processing, esterification, transesterification and
ketonization.
1.1
1.3
1.5
1.7
1.9
0
0 .2
0.4
0 .6
C
/
H
c
i
m
o
t
A
Atomic O/C
TCR of wood
Fast pyrolysis of wood
HDO of wood over Ni/SiO₂
HDO of wood over Ni/ZrO₂
Fig. 10 Diagram of Van
Krevelen for bio-oil from
the TCR of woody biomass
[145, 146], fast pyrolysis
of woody biomass [57, 82]
and hydrotreated bio-oil
from woody biomass fast
pyrolysis over nickel-based
catalysts [148]
H. Jahangiri et al.
sustainability credentials. In addition, the hydrogen yields can be maximized by
injection of steam (which can be TCR aqueous phase) into the TCR system, which
promotes a water gas shift reaction [129, 140]. This is in contrast to fast pyrolysis
that needs an outside source of H 2 to improve the bio-oil properties [147].
The Van Krevelen diagram represents the O/C and H/C ratios for varied technologies (Fig. 10). The O/C and H/C of bio-oil from the TCR of woody biomass
were 0.19 and 1.27, respectively [145, 146]. However, the bio-oil from fast pyrolysis of woody biomass has considerably higher values of O/C (0.56) and H/C (1.56)
than TCR results [57, 82]. Additionally, the O/C and H/C of hydrotreated bio-oils
from fast pyrolysis of woody biomass over Ni-based catalysts are slightly different
from the TCR values [148]. Therefore, TCR displayed significant enhancement of
bio-oil properties and stability characteristics.
7 Upgrading of Bio-oil
Fast pyrolysis bio-oils have a lot of drawbacks such as thermal instability, high
oxygen content and high viscosity and corrosiveness. Therefore, fast pyrolysis biooil upgrading should be performed to decrease the oxygen content and acidity
before its application [57, 80]. There are different methods to upgrade bio-oil,
which are emulsification, filtration, polar solvent, catalytic and TCR cracking,
hydrotreatment, aqueous phase processing, esterification, transesterification and
ketonization.
1.1
1.3
1.5
1.7
1.9
0
0 .2
0.4
0 .6
C
/
H
c
i
m
o
t
A
Atomic O/C
TCR of wood
Fast pyrolysis of wood
HDO of wood over Ni/SiO₂
HDO of wood over Ni/ZrO₂
Fig. 10 Diagram of Van
Krevelen for bio-oil from
the TCR of woody biomass
[145, 146], fast pyrolysis
of woody biomass [57, 82]
and hydrotreated bio-oil
from woody biomass fast
pyrolysis over nickel-based
catalysts [148]
H. Jahangiri et al.