Effects of gas-‐phase alkali species on tar reforming catalyst performance in biomass gasification systems: How to achieve an improved understanding at realistic conditions
by
Klas Engvall(Department of Chemical Engineering and Technology, KTH)
→
Europe/Stockholm
FD41
FD41
Description
Thermochemical conversion of biomass by means of gasification
is
an
attractive
solution
to
replace
fossil
with
renewable
and
sustainable
fuels.
In
case
of
gasification
of
biomass,
tar
mitigation
is
one
of
the
greatest
technical
challenges
to
overcome
before
commercialization.
Secondary
catalytic
tar
conversion
at
a
high
temperature
is
a
feasible
way
to
solve
this
problem.
Today’s
available
catalytic
conversion
technologies
generally
are
limited
by
sensitivity
to
alkali
salts,
inducing
deposit
formation
at
the
surface.
This
is
resolved
by
introducing
an
upstream
low
temperature
filtration
step,
where
alkali
salts
is
separated
from
the
product
gas.
Due
to
heat
penalties,
this
is
not
energy
efficient.
Therefore,
considerable
efforts
are
made
to
develop
a
catalytic
conversion
process
positioned
directly
after
the
gasifier
to
even
out
the
process
temperature
profile.
To
make
things
more
complicated,
alkali
is
also
promoting
surface
carbon
gasification,
reducing
surface
carbon
formation.
Alkali
is,
hence,
added
in
small
quantities
to
the
catalyst
material.
One
way
to
tackle
these
effects
is
to
develop
more
alkali
tolerant
catalysts
capable
of
storing
or
using
gas
phase
alkali
in
the
catalytic
conversion
process.
The
development
of
such
a
catalyst
or
catalysts
requires
a
thorough
understanding
of
the
effect
of
gas
phase
alkali
in
connection
with
other
species
such
as
sulphur.
The
issues
to
be
addressed
are
numerous,
including
selection
of
relevant
chemical
reactions
and
processes
to
investigate,
methodologies,
the
pressure
gap,
catalyst
materials,
etc.
The
Seminar
will
present
an
overview
of
on-‐going
research
activities
at
Chemical
Technology,
KTH
and
partners
in
research.
