Sustainable Chemistry for the Environment,
Год журнала:
2024,
Номер
6, С. 100107 - 100107
Опубликована: Май 12, 2024
Lignin,
an
abundant
renewable
biopolymer
found
in
plant
cell
walls,
is
enriched
phenolic
units
within
its
complex
molecular
structure.
Unlocking
potential
as
alternative
feedstock
(bio)refining
has
posed
a
long-standing
challenge,
even
though
it
holds
immense
promise
for
replacing
fossil-derived
and
aromatic
compounds.
This
study
focuses
on
fast
pyrolysis
effective
thermochemical
depolymerization
method
of
lignin,
coupled
with
the
situ
catalytic
upgrading
aiming
to
produce
valuable
bio-oil
dealkoxylated
(alkyl)phenolic
Lignin
was
isolated
via
organosolv
process
from
beechwood
sawdust
(hardwood
biomass).
Various
acidic
aluminosilicate
catalysts
(e.g.,
zeolites,
such
ZSM-5,
Beta
USY,
amorphous
silica
alumina)
were
applied,
having
different
Si/Al
ratio,
porous
properties.
Fast
experiments
conducted
fixed-bed
bench-scale
reactor
at
two
distinct
temperatures
(500
600
°C),
employing
contact
times
lignin-to-catalyst
ratios.
Non-catalytic
revealed
that
higher
temperature,
significantly
influences
bio-oil's
composition
yield,
resulting
conversion
initially
formed
alkoxy-phenols
alkyl-phenolic
compounds,
reaching
47%
relative
concentration
oC,
while
also
yielding
high
amount
up
43
wt.%.
Among
tested,
zeolite
ZSM-5
(Si/Al=40)
proved
be
most
efficient,
shifting
chemical
profile
(mainly
BTX)
57%,
owing
unique
microporous
structure
acidity.
Depending
catalyst
type,
balance
between
BTX
monomer
aromatics
naphthalenes
observed.
well
obtained
products
(bio-oil,
non-condensable
gases,
char/coke-on-catalyst)
thoroughly
characterized
using
various
analytical
techniques.
The
results
associated
physicochemical
properties
catalysts,
providing
insights
into
underlying
reaction
mechanisms.
International Journal of Molecular Sciences,
Год журнала:
2023,
Номер
24(9), С. 8330 - 8330
Опубликована: Май 5, 2023
Developing
renewable
biomass
resources
is
an
urgent
task
to
reduce
climate
change.
Lignin,
the
only
aromatic
feedstock
present
in
nature,
has
attracted
considerable
global
interest
its
transformation
and
utilization.
However,
complexity
of
lignin's
structure,
uncertain
linkages,
stability
side
chain
connection,
inevitable
recondensation
reaction
fragments
make
lignin
depolymerization
into
biofuels
or
platform
chemicals
a
daunting
challenge.
Therefore,
understanding
structural
characteristics
reactivity
relationships
crucial
for
achieving
high-value
utilization
lignin.
In
this
review,
we
summarize
key
achievements
field
conversion
with
focus
on
effects
β-O-4
content,
S/G
ratio,
sources,
"ideal"
lignin-catechyl
We
discuss
how
these
influence
formation
monomer
products
provide
outlook
future
direction
depolymerization.
Chemical Reviews,
Год журнала:
2024,
Номер
unknown
Опубликована: Сен. 17, 2024
In
this
Review,
all
known
chemical
methods
for
the
conversion
of
renewable
resources
into
benzenoid
aromatics
are
summarized.
The
raw
materials
that
were
taken
consideration
CO
Fuel Processing Technology,
Год журнала:
2024,
Номер
254, С. 108034 - 108034
Опубликована: Янв. 11, 2024
To
develop
a
structure-tailoring
catalyst
for
catalytic
conversion
of
lignin
value-added
chemicals,
series
novel
Fe-Ce-Al
metal
oxide
catalysts
was
synthesized
via
different
methods
to
tailor
activity
and
structure
pyrolysis
enhance
hydrocarbon-rich
bio-oil.
The
results
revealed
that
FeCeAl-CO
derived
from
coprecipitation
method
with
smaller
particle
sizes
exhibited
excellent
deoxygenation
due
higher
Lewis/Brønsted
acid,
reversible
Ce3+/Ce4+
redox
pairs,
tailorable
oxygen
vacancies
promoted
β-O-4,
aromatic-OCH3
side-chain
cleavage.
Additionally,
facilitated
hydrogen
transfer,
cleavage
aromatization
reactions,
while
wet
impregnation
beneficial
demethoxylation
H-abstraction
activity.
During
process,
over
57.91%
hydrocarbon,
including
20.21%
25.71%
aromatics
olefins
were
achieved
catalyst.
Over
60.74%
phenols
52.48%
alkylphenols
obtained
Fe-Ce/Al2O3-IM
synergistic
effect
FeOx
CeOx
species.
great
stability
after
fourth
run,
greater
Brønsted
acid-favored
coke
deposition,
active
species
leaching,
oxidation
pore
blockage
the
key
reasons
deactivation.
Therefore,
these
findings
could
provide
cost-effective
designing
direct
generate
upgrading
