Kind: captions
Language: en
nitrogen is everywhere it's a
fundamental building block of life
it makes up 78 of the atmosphere and
it's in these
tiny micro bubbles in my starbucks nitro
cold brew
and yes this episode is sponsored by
starbucks
they challenged me to liquify nitrogen
out of the air
and that's what i'm going to be doing in
this video but first i'm going to try
nitro cold brew for the first time
it's subtly sweet without having to add
sugar
and obviously it's cold and frothy and
i'm gonna explain why nitrogen makes
this possible but first i'm gonna try to
liquefy some nitrogen for myself out of
this atmosphere
come on let's go okay in order to make
liquid nitrogen we need a way to make
the air
really cold and to do that i'm going to
use this
cryo cooler so essentially what's inside
here is a
cylinder of helium and a couple pistons
so there's a piston that compresses the
helium down into this section
and when it does that it makes that gas
really hot
and so that heat gets ejected to the
surroundings
through this heat sink then the helium
is expanded
down in here and as that happens it gets
really cold so it absorbs the heat
from the surroundings so this is the
part of the cryo cooler that is going to
get down to
less than minus 200 degrees celsius so
cryogenic temperatures this is the place
where we can really liquefy some gas
so i want to put this to the test and
first do a sort of
simple proof of concept and make sure
that this is working and just try to
liquefy
air liquefy the air in this room
this is alan pan allen is handier with
tools than i am so
uh brought him in to help me make this
happen how should people know you alan
like
what do you get into what's your thing
uh i'm a failed mythbuster and also i
have a youtube channel called
sufficiently advanced
you may know alan from his creations and
relevant to this project
shooting liquid nitrogen from his hands
i'm definitely breaking your drill by
the way that plastic is coming right i
see that did i measure this correctly
let's see does it go in and stop right
there oh my god look at that
perfect so now let's turn it on and you
can listen you can hear it turn on
oh the pump is starting it's purring
this is the moment of truth been running
the crowd cooler for about four hours
hopefully getting some liquid air in
there i bet you 50 bucks there's at
least 50 milliliters of liquid air in
there 50 milliliters
sir that's not even that much it isn't
even that much
i'll be amazed i'll be amazed if it
happens oh that that's 50 milliliters
right there i bring you
a 50 milliliter
do beaker feel any sloshing
i hear something i hear something i hear
something in your liquid
we have made liquid air that's how much
have we made
50 milliliters is that how much we make
of liquid air
oh dude that's 50 milliliters of liquid
air
i know it doesn't look like much but to
make 50 milliliters of liquid air
we needed to condense around 35 liters
of air from the room
what's funny to me is i've done a lot of
experiments with liquid nitrogen
but this feels like the most precious
liquefied gas that i've ever had because
we made it ourselves there was
more than 50 ml i know we didn't shake
on it but you definitely owe me 50
i definitely do
because that's impressive from just a
few hours you know
running it for the first time liquid
oxygen is paramagnetic
which means it's attracted to permanent
magnets i'm going to use this effect to
try to extract some liquid oxygen
something oh dude you got it you got
some
see that droplet at the end of the
magnets to make sure it really was
liquid oxygen we tested how it affected
a flame
so that's for sure oxygen that is liquid
oxygen
you can see how the matchstick reignites
with the liquid oxygen
and the flame spreads towards the higher
concentration
of oxygen
[Applause]
oh
[Applause]
there you go we have made liquid air
next step
remove the oxygen and just make liquid
nitrogen
okay it is day two and time to scale up
we
are moving the crowd cooler to a bigger
stand should i just go yeah go for it
i'm putting a lot of sawdust into your
into your carpet i'm sorry
it's okay
to make pure nitrogen we need
pressurized air
so i've got an air compressor here in
the garage the pressure of this
compressor is about 10 atmospheres
so i'm going to pressurize this line
here
now the first thing we got in the line
is a filter to remove
water vapor now to get pure nitrogen
this is the key component it is a
nitrogen membrane
and what it actually contains is a bunch
of hollow
polymer fibers and so we supply
compressed air in this
end and all of the gas molecules try to
diffuse
out of those fibers because of that high
pressure but
these polymer fibers are made out of a
material that is selectively permeable
it allows
oxygen and carbon dioxide and water
vapor to diffuse out
much faster than nitrogen and so those
gases actually come out preferentially
through these holes so what you're left
with at the end
is a high concentration of nitrogen and
to get the highest purity what you need
to do is have a very high pressure
and a slow flow rate because that gives
a lot of time for those other gases to
escape whoa
i don't know about this gauge so what i
want to call and watch is how long it
takes to
increase the pressure in the tank well
we worked it out yesterday and we
figured out if it takes six minutes to
fill the tank
at 100 psi then we've got 98 pure
nitrogen
cool perfect right but we just have to
be very slow with this tank filling and
i don't know if we are that slow
we're going to try to check the oxygen
levels
that have come through this membrane
let's put some money on it
how about 50 bucks as the oxygen is less
than 5
yeah are you gonna bet that because i
will easily take that back yeah
all right i don't think this went very
well because that was the first filling
of the tank so we weren't high pressure
going through the membrane
so i don't think it's gonna be i think
we're good 95 percent nitrogen 95
nitrogen so this meter measures oxygen
so we're looking for a number less than
five percent which i suspect we will not
see
oh can he oh it's it's
going away come on five percent for oh
there it is whoa here we go 99 99
not over 99 percent 99.2 99.3
i am shocked there's no oxygen in this
air baby it's all nitrogen
99.5 i am so shocked right now
so we're at 50 bucks for the liquid air
bet
we're at 50 bucks yeah you just found
yourself 100 bucks
look at that 99.7 percent nitrogen
this is insane and you can understand
why there would be an alarm
if you were in a room with
1.3 oxygen yeah i knew it
i told you you knew this would hurt you
yes
okay so we've achieved i guess the
second part of this
which is isolating nitrogen from the
atmosphere and now we just have to get
it super cold
what we gotta do is we gotta put this
thing
here for better insulation we scaled up
to a doer
that's impressive kind of sci-fi janky
garage sci-fi kind of a look
go ahead and lower that it'll just
squish right on
i hope i mean that's that's sealed you
know
i think uh honestly we could just turn
it on and
see if it works at this point start
bleeding some nitrogen in there
so that when the nitrogen goes in there
it'll push out
any remaining air that's still in the
tank
i'm going to switch on the variac which
powers up
the crow cooler the other thing i need
is the
fan yes this is the fan i'm gonna plug
that in
that's a cooling fan of the grout cooler
we're up to
eight watts
okay i have been running the nitrogen
setup for about
three hours and my concern because the
temperature on the thermocouple never
got very
low was that i wasn't actually making
any liquid nitrogen so
i've stopped the test and i just want to
see
whether or not there is anything in here
it doesn't sound like it
nothing huh what i think could be part
of the problem
i was putting nitrogen possibly at a
rate that's too high
so this is effectively nitrogen coming
in at
room temperature and i wonder if it was
just
too warm for it to ever reach the
liquefying temperature right here at the
end of the uh
the cold finger of the crowd cooler so i
feel like i need a slower flow rate
maybe a better way to introduce the
nitrogen into the dewar
not as easy as i'd hoped okay my plan is
to go with a
smaller flask something like this
and we're gonna use its lid to make a
nice tight seal
except we're gonna cut a hole through
the top i think it's good enough for
this cold finger
all right then we're gonna try to drill
a hole in the side
uh for the supply of nitrogen we need to
make nice
tight seals around both of those things
so that is gonna be the challenge
this is the uh kind of the new design
here that we've got
i feel like it's pretty good i think
it's gonna work i think you're gonna
wake up
and there's gonna be like a nitrogen in
there
i bet you a hundred and
sixty dollars that there is liquid
nitrogen in there
i don't know if i'll take that out
i'm going to turn down the cryo cooler
and let's see what we got
it looks cold yeah there's definitely
some condensation
so there's something cold in there
what do you see oh there's luminite
there's like this much that's liquid
nitrogen
we have some liquid nitrogen out of the
air
that was so much effort
so what do you do with homemade liquid
nitrogen well
make homemade ice cream just a bit of
cream and sugar
and then the liquid nitrogen
the most precious liquid nitrogen i've
ever had
is it enough to make ice cream come have
a look have a look
that is delicious by freezing everything
so fast because it is
minus 196 celsius you get really small
ice crystals and so that gives the ice
cream a really smooth
flavor smooth texture in a lot of stores
starbucks ii generates nitrogen just out
of the air because
why not it's an available resource they
purify it and then
infuse it in line into the drink
creating millions of those tiny bubbles
that gives it its unique texture so
nitrogen bubbles are much smaller than
the bubbles you're normally used to the
carbon dioxide bubbles that you'd find
in soda and that gives this a sort of
creamier
texture the other nice thing about
nitrogen is that it's totally inert so
it doesn't react with the drink
co2 reacts with water creating some acid
which you might like in soda you might
want a little bit of a sour tangy flavor
but you don't want that in coffee hence
the nitrogen
one thing i found really interesting
when they were pouring this nitrocol
brew
is that you can actually see bubbles
coming down on the sides of the glass
and that's strange because these bubbles
are obviously
less dense than the coffee they should
be
rising up to the surface so why are they
doing that well the answer is
the nitrogen bubbles are rising up to
the surface a lot in the center
of the drink and so that actually
creates a current that pushes
them down around the outside and so
that's why you see those bubbles
cascading down
at the beginning when you're pouring the
nitro cold brew so there you have it
nitrogen is everywhere and useful for
lots of things if you want to try out a
nitro cold brew i'll put a link to order
it down in the description
and thanks for watching
you