Friday, October 4, 2013 11:30 am
-
12:30 pm
EDT (GMT -04:00)
Dr.
Poupak
Mehrani
Chemical
and
Biological
Engineering
Department
University
of
Ottawa
Fluidized
beds
including
those
of
gas-phase
are
widely
used
in
industry
due
to
their
excellent
features
including
providing
high
degree
of
mixing,
heat
transfer,
mass
transfer,
to
just
name
a
few.
In
this
talk
a
brief
summary
of
research
presently
carried
out
by
my
research
team
in
the
areas
of
polymerization
and
clean
energy,
where
fluidized
bed
reactors
are
employed,
will
be
presented.
(i)
In
petrochemical
industry
fluidized
bed
reactors
are
adopted
for
gas-phase
ethylene
polymerization
to
produce
polyethylene.
However,
in
such
processes
electrostatic
charges
are
generated,
resulting
in
the
adhesion
of
polyethylene
and
catalyst
particles
to
the
reactor
wall.
This
in
turn
causes
long
shut
down
periods
for
reactor
clean-up
and
significant
economic
losses.
At
the
University
of
Ottawa,
a
comprehensive
experimental
program
has
been
established
to
better
understand
this
occurrence
underlying
mechanisms.
A
new
online
charge
measurement
technique
has
been
developed
that
allows
the
quantification
of
the
degree
of
fluidized
bed
fouling.
This
method
has
been
implemented
in
a
pilot-scale
atmospheric
and
a
high-pressure
fluidization
facility
(built
in-house).
The
later
system
enables
the
study
under
industrially-related
operating
conditions
of
polyethylene
reactors
(25
atm
and
100°C).
(ii)
In
recent
years,
the
dependence
of
world
energy
on
fossil
fuel
sources
has
been
diversified
towards
clean,
renewable
alternative
sources
such
as
biomass.
However,
conversion
technologies
are
required
for
producing
energy
from
biomass
and
in
order
for
bioenergy
to
enter
the
energy
market
such
as
those
of
the
transport
fuel.
Two
conversion
methods
of
biomass
gasification
(to
produce
syngas)
and
pyrolysis
(to
produce
bio-oil)
are
currently
being
investigated
in
pilot-scale
gas-phase
fluidized
bed
reactors.
The
goal
of
this
research
is
to
evaluate
the
reactor
performance
by
investigating
the
effects
of
reactor
scale
and
feedstock
properties
on
the
products
yield.
(iii)
The
negative
environmental
effects
of
CO2
emissions
represent
a
growing
problem
as
the
utilization
of
fossil
fuels
such
as
coal
is
increasing
and
can
be
expected
to
do
so
for
the
future.
Therefore,
technologies
associated
with
CO2
capture
and
storage
are
found
to
be
essential
to
reduce
these
emissions.
Research
is
underway
to
investigate
a
new
process
for
CO2
capture
for
post
combustion
and
in-situ
pre-combustion/gasification.
The
research
is
focused
on
integration
of
fluidization
processes
of
calcium
looping
(CaL)
and
chemical
looping
combustion
(CLC)
into
in
a
new
process
and
to
develop
composite
materials
combining
the
CaL
and
CLC
sorbents
into
a
single
composite.