Sustainable Chemistry for the Environment,
Journal Year:
2024,
Volume and Issue:
6, P. 100107 - 100107
Published: May 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.
Energies,
Journal Year:
2023,
Volume and Issue:
16(14), P. 5403 - 5403
Published: July 16, 2023
In
order
to
satisfy
the
increasing
need
for
renewable
chemicals
and
fuels,
it
is
important
replace
petroleum-based
products
with
alternative
feedstocks.
Lignocellulosic
biomass
considered
be
most
capable
source
producing
sustainable
biofuels.
Catalytic
co-pyrolysis
(CCP)
a
process
that
involves
simultaneously
pyrolyzing
plastics
produce
combination
of
liquid
gaseous
products,
such
as
bio-oil
syngas.
Catalysts
are
used
raise
reaction
degree
selectivity
process,
choice
catalyst
dependent
on
physico-chemical
features
feedstock.
pyrolysis
useful
method
high-quality
biofuels
directly
from
biomass,
although
typically
yields
modest
amount
aromatic
hydrocarbons
(HCs)
large
coke,
even
highly
effective
catalysts.
Adding
co-reactant
high
in
hydrogen
CCP
can
significantly
increase
yield
aromatics
while
reducing
coke
formation.
The
use
help
address
environmental
issues
related
waste
plastic
disposal
improve
energy
security.
This
review
article
thoroughly
discusses
mechanism
catalytic
co-pyrolysis,
influence
how
addition
quality
output
production
oxygenated
compounds
coke.
importance
various
catalysts
(such
biochar,
activated
carbon,
acid
base
catalysts)
improving
obtained
also
compared
discussed.
Biomolecules,
Journal Year:
2023,
Volume and Issue:
13(5), P. 717 - 717
Published: April 22, 2023
Lignins
are
the
most
abundant
biopolymers
that
consist
of
aromatic
units.
obtained
by
fractionation
lignocellulose
in
form
"technical
lignins".
The
depolymerization
(conversion)
lignin
and
treatment
depolymerized
challenging
processes
due
to
complexity
resistance
lignins.
Progress
toward
mild
work-up
lignins
has
been
discussed
numerous
reviews.
next
step
valorization
is
conversion
lignin-based
monomers,
which
limited
number,
into
a
wider
range
bulk
fine
chemicals.
These
reactions
may
need
chemicals,
catalysts,
solvents,
or
energy
from
fossil
resources.
This
counterintuitive
green,
sustainable
chemistry.
Therefore,
this
review,
we
focus
on
biocatalyzed
e.g.,
vanillin,
vanillic
acid,
syringaldehyde,
guaiacols,
(iso)eugenol,
ferulic
p-coumaric
alkylphenols.
For
each
monomer,
its
production
summarized,
and,
mainly,
biotransformations
provide
useful
chemicals
discussed.
technological
maturity
these
characterized
based
on,
scale,
volumetric
productivities,
isolated
yields.
compared
with
their
chemically
catalyzed
counterparts
if
latter
available.
