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