New solutions for the oxygen industry
[Applause]
our society
depends on oxygen not just us humans for
breathing
but our industry as well oxygen is the
fifth
most used chemical in the world and we
use over 100 million
tons of it each year 50
of this goes into the production of
steel while the rest is used for making
plastics
many different chemicals for welding and
maybe most importantly in hospitals
helping people breathe
where do we get all this oxygen air
the fantastic thing around us that
contains roughly eighty percent
nitrogen and twenty percent oxygen
our lungs are pretty good at making this
oxygen accessible
to us but the industry doesn’t have
lungs
instead they use an extremely
complicated and energy demanding process
called cryogenic distillation or very
cold
distillation in order to turn air into
pure oxygen
it needs to be cooled down to as low as
negative 185 degrees
celsius at that point air turns into a
liquid
which can be distilled in kind of the
same way you distill alcohol
cooling down air to such a low
temperature requires enormous
amounts of energy meaning a lot of co2
release into the atmosphere
just imagine how much energy your
kitchen freezer uses and that can only
reach negative 18
degrees if our whole world depended only
on renewable energy sources
this wouldn’t be such a big issue but
that is not the case today
or even for many decades ahead
so what should we do we can’t reduce the
amount of oxygen we use
the demand for oxygen is actually
expected to rise almost seven percent
in the next five years and this summer
the world health organization warned of
a possible oxygen shortage
in hospitals due to covid 19.
we could try to improve the cryogenic
distillation process
but that wouldn’t improve the energy
consumption by very much
we need a new and completely different
way to produce
pure oxygen gas industrially worldwide
what if we instead of using all that
energy on liquefying the air
could just filter out the oxygen from
air directly
this is where ceramic membranes come
into play
so what are membranes and how do they
work
imagine that you’re standing outside a
nightclub looking at the people inside
dancing between you and a night of fun
is a security guard blocking the way
with a vip guest list in his hands
and you’re lucky and get through because
you’re on the list
but most of the others will have to stay
out in the cold
i am trying to make just such a security
guard
working at the nightclub where the
people in line are air
and it looks like this
it may look small but it may have a huge
impact
on the oxygen industry one day this
is the ceramic membrane and the only
thing on this vip
guest list is oxygen
this membrane is made out of a material
that conducts
oxygen by using this material we can
filter out oxygen from the air directly
without cooling it down
saving a lot of energy and therefore
also co2
and money if we have air on one side
an empty container on the other and this
membrane in between
oxygen will willingly go through the
membrane and into the container
resulting in 100 pure oxygen gas
ready for use we do then
not need to use all that energy on
cooling down the air
or distilling that liquid afterwards
ceramic membranes made from oxygen
conductive materials have been
researched a lot
over the years and was a pretty pretty
hot topic
in the 90s but so far the result has
been membranes with either poor
stability
or low effectivity their materials need
temperatures as high as a thousand
degrees to function properly
and at those temperatures the materials
degrade and the membrane just
falls apart for many years people have
tried to improve these materials
either by making them more stable over
time or improving their
efficiency while these materials are
somewhat getting better
there’s still a long way to go
as material scientists we always try to
make better materials
either by improving what we have or
finding new ones that can change
everything around us
finding these new and revolutionary
materials is not simple
because understanding what you need when
you don’t have it is difficult
and it’s easier to just try to better
what you’re already working on
the world of ceramic membranes for
oxygen production need to look outside
the box for new possible materials
what i am working on is a completely new
type of material
never been used for these kinds of
membranes before
it has no problems with standing higher
temperatures it is
much more stable and should also
function at lower temperatures
than the normal materials but how do we
know that it works
before making a membrane out of this we
need to test the properties
of the material you wouldn’t like to go
to a night club if there for one
wasn’t enough space for you on the guest
list and two
the queue was so slow that you never got
to go inside
the same is also applicable for ceramic
membranes
the more space there is for oxygen
inside the material the more can pass
through
at the same time and the faster it goes
through the more efficient
it becomes one way to determine how much
oxygen can be inside the material at the
same time
is thermogravimetric analysis and this
sounds more complicated than it is
thermo means heat and gravimetry means
measuring weight so what you do is heat
up the material
and see how the weight changes when
oxygen enters the material it becomes
heavier
and when oxygen leaves the material it
becomes lighter
this way we can figure out how much
oxygen is inside the material at the
same time
at different temperatures and this this
is
key temperature is very closely related
to energy and the harder it is
the more energy oxygen has and the
faster it can move
having a membrane that is efficient at
letting oxygen through
is a necessity to be able to compete
with the traditional oxygen
process but having a security guard
who’s really quick
at checking people off the guest list
doesn’t really help if all the guests
are slow as snails
these three cylinders represent the
amount of oxygen inside the material at
room temperature
medium temperature and higher
temperatures
we can see that there is definitely the
most space for oxygen at room
temperature
but at that temperature oxygen has zero
energy
oh it really doesn’t want to move and
the thought of going through the
membrane is
out of the option but as the temperature
rises so does its energy
and at higher temperatures oxygen is
practically sprinting through the
material
it’s these high-energy oxygen atoms that
we would most like
to use as a faster transport of oxygen
means a more efficient membrane but if
my membrane only works at higher
temperatures then we’re back at square
one when it comes to saving energy
we need to compromise and rather use the
fairly active oxygen at medium
temperature
that way it’s still efficient enough to
use and we’re saving a lot of energy
but according to the results we don’t
have that much oxygen to use at that
temperature
and that’s a problem or a challenge
and luckily there is a solution we
material scientists are in fact allowed
to do something that no one else
should do doping
legal doping and we find our steroids
in the periodic table by adding a small
amount of an element that is not present
in the material to begin with
we can enhance wanted properties and
produce
unwanted ones doping is one of material
science biggest tricks
and is being used everywhere so let’s
put my security guard on steroids
after doping the material we test it
again
and we see that we increase the amount
of oxygen that can be inside it at both
room temperature medium temperatures
and higher temperatures these oxygen
here are the key to making these
membranes a reality
and now we have enough of them to make
the membrane be at its
best performance but making a membrane
out of this material
is not very straightforward for oxygen
to be able to pass through the material
it has to push itself forward
in between the other atoms and to make
it worse oxygen is
pretty lazy if the membrane is too thick
then it can’t be bothered to go through
therefore
these membranes need to be thinner than
a human hair
but having such a thin sheet of material
wouldn’t be very durable in itself and
would probably just break when you try
to touch it
this whole thing here is actually not
the membrane
only the top layer of it yes
if we look at it using an electron
microscope it looks
like this kind of looks like the
frosting on top of a very dry and hard
cake
this recipe for this frosting is still a
secret
so far this project is at the stage
where we’re trying to make a functioning
prototype
out of this membrane and if it works
then it can both
be used for large scale oxygen
production and
for vital oxygen concentrators in
hospitals
science is about making the world a
better place
for all of us sometimes that means
improving what we do
one small step at the time other times
we need to think outside the box and
start over
and the oxygen industry needs a fresh
start
we will need more and more oxygen in the
years to come
and this is not a resource that can be
exchanged
for something else by using these new
membranes
we are not just thinking outside the box
we are recreating
the box using a completely new
material thank you