Sciencemadness Discussion Board - how to get make a nitrogen atmosphere?

how to get make a nitrogen atmosphere?

Db33 - 4-3-2017 at 10:40

There is a reaction i want to do, everything about the reaction seems doable and quite easy except it says the reaction was stirred under nitrogen for a few hours.

Now in a good lab i know they have tanks with nitrogen and they have very easy to use pieces that make it easy to take some of that and fill a balloon and then use that for the vessel.

But for someone without a sophisticated lab just using household items. How can this be done?

i know Amazon sells these
https://www.amazon.com/Disposable-Tank-of-Nitrogen-Filled/dp/B013KC9FUK/ref=sr_1_1?ie=UTF8&qid=1488652720&sr=8-1&keywords=nitrogen

but how do i get this into a flask to flush it and keep it under nitrogen?

AJKOER - 4-3-2017 at 13:03

One could try placing a dish of fine iron particles, sprayed with a fine mist of an acid (like lemon juice) with added NaCl, floating on water in a vessel half full of air. If you arrange it so that the dish is floating in an inverted jar of air/H2O, you can see if the O2 is being consumed.

An alternate related reaction would be an acid mist applied to Cu2O (in place of iron) and a touch of sea salt.

The idea stems from a report, I once read, of the deaths of sewer workers in a partially drained iron pipe from oxygen depredation. My possible take is that a rough iron surface freshly scrubbed by sewer generated acid and/or newly forming ferrous, developed a big appetite for the available oxygen. One possible reaction could be given by:

4 Fe(ll) (aq) + 4H+ + O2 → 4 Fe(lll) + 2 H2O (see http://corrosion-doctors.org/Experiments/rust-chemistry.htm )

And a similar reaction with Cu(l), acid and oxygen. The role of salt is to serve as a good electrolyte for the electrochemical reaction, which can be described by:

Cathode: O2 + 4 H+ + 4 e- ---> 2 H2O (see page 20-13 at http://www.public.asu.edu/~jpbirk/CHM-115_BLB/ClassNotes/chp... )

Anode: Fe (s) ---> Fe(ll) + 2 e-

Or, following the consumption of surface iron:

Anode: Fe(ll) ---> Fe(lll) + e-

[Edit] You may even get better results mixing Fe with Cu(ll), due to the expected formation of redox couples, in an equilibrium reaction:

Cu(ll) + Fe(ll) = Cu(l) + Fe(lll)

[Edited on 4-3-2017 by AJKOER]

Acuyo - 4-3-2017 at 15:38

FWIW I've heard of people who simply need an inert, and not necessarily nitrogen atm to use "canned air", apparently most brands are quite inert to much of anything, although I did hear about one brand to avoid -- sorry that I don't remember more, but it's an idea, just reads the msds before use..

yobbo II - 4-3-2017 at 17:36

An engine exhaust has been used as an oxygen free source in places.

Metacelsus - 4-3-2017 at 21:02

Depending on the particular reaction, you might be OK with just keeping it in a tightly sealed vessel with minimal headspace. You'd lose a few percent yield, but it wouldn't cause major problems.

However, some reactions are very air-sensitive (especially those employing oxygen-sensitive catalysts) and this wouldn't work for those ones.

unionised - 5-3-2017 at 02:08

Well, part of the answer to the OP is to buy something like this
https://www.amazon.com/Professional-Flushing-Nitrogen-cylind...

But even that's not the whole story since you need to be sure of regulating the rpessure down to a very low level (glassware will not take high pressures safely)

Canned air is OK for a lot of things as long as it isn't heated. It depends on what you are trying to do and the OP doesn't say a lot about that.

Helium- as balloon gas- is also an option.

Db33 - 5-3-2017 at 08:53

the reactions that would be done under the nitrogen atmosphere are reductive alkylation and amination followed by N-acylation. So would the yield loss be big if these were done under normal atmosphere?

Melgar - 8-3-2017 at 12:21

Quote: Originally posted by unionised

Well, part of the answer to the OP is to buy something like this
https://www.amazon.com/Professional-Flushing-Nitrogen-cylind...

But even that's not the whole story since you need to be sure of regulating the rpessure down to a very low level (glassware will not take high pressures safely)

Canned air is OK for a lot of things as long as it isn't heated. It depends on what you are trying to do and the OP doesn't say a lot about that.

Helium- as balloon gas- is also an option.

If you just want an oxygen scavenger, these are as cheap as you'll get, and actually work very well:

https://www.google.com/shopping/product/8809343064370531838

They're just filled with reduced iron particles, salt, and a bit of moisture to catalyze their oxidation fast enough to heat them. I don't think they'd scavenge CO2 though. For that, you'd probably need an alkali hydroxide or similar.

Keeping your solvent at reflux is one common way to keep air out, since the solvent vapors displace air.

Argon is probably cheaper than helium, since it's extracted as part of normal air processing. It certainly is cheaper per unit mass. It also wouldn't leave nearly as quickly as helium would through a small leak, since it's approximately the same density as air is. You can get larger amounts from welding supply places, and smaller amounts from neon sign stores.

unionised - 8-3-2017 at 14:10

The only advantage to helium is that you can buy it from the supermarket

PirateDocBrown - 8-3-2017 at 15:32

One inexpensive route could start using automotive refrigerant. It's cheap and readily available, even at Wal Mart. Simple regulators are also sold for it.

Zyklon-A - 8-3-2017 at 19:01

If you're not invested enough to consider a cylinder, there's lots of options to choose from. Running air through a reduction tube and is cheap and can be efficient. But it's not a quick build and tedious if you skimp on materials.

If you have ammonium chloride and sodium nitrite you can generate nitrogen with no special apparatus. You'll only have water vapor to deal with
There's lots of different reactions that work too, but this is the only one I've used.
I know many (maybe all) helium balloons have oxygen added, I would imagin balloon filling cylinders will be premixed so pay attention.

Lambda-Eyde - 9-3-2017 at 12:17

Buy a one liter disposable tank of nitrogen or argon for welding, they are cheap enough and readily available if you know where to look. Get a suitable regulator for it, a hose and a ground glass tubing adapter and you have everything you need for a basic inert atmosphere setup. As long as this can be had so cheap there are no good reasons to be dicking around with helium, carbon dioxide, refrigerants, makeshift oxygen scavengers or canned "air" (these are actually chlorofluorocarbons, very soluble in organic solvents but mostly inert, except for being flammable).

Db33 - 10-3-2017 at 12:48

its not a problem of getting the nitrogen which i should have said, my problem is how to get the nitrogen into a flask and keep it there. I saw in a video that they used a syringe with a balloon on the end of it and that was put in the top of the flask stopper and then another needle is used to create another hole so that the flask is flushed out an dthne i assume the syringe will slowly let more nitrogen in over time? im not sure but i need to know how to do it without a sophisticated lab like a university.

Tsjerk - 10-3-2017 at 14:34

That is about how you do it yes. You can first flush straight from the hose, after that do the balloon thing, if you take out the "exit" needle at some point you should be able to keep it pressurized over night. As long as your stopper or diafragma is closely fitting

What reductant do you use? If it is not LiAlH4 you should be fine without nitrogen. Often the guys and girls writing those articles use nitrogen for about everything just because they can, using a balloon for them is easier than using a drying tube to keep water out.

Do keep water out with a tube filled with CaCl2. Even that wouldn't ruin your reaction, but better save than sorry.

unionised - 11-3-2017 at 04:20

Quote: Originally posted by Zyklon-A

I know many (maybe all) helium balloons have oxygen added, ....

How do you know that?
my understanding is that it's a myth.

PirateDocBrown - 14-3-2017 at 11:18

I have used balloon needles like you have described. You simply take a balloon, and seriously, in grad school they were dollar-store kids' play balloons... and put it on a Luer-lock needle with a small rubber band. These are filled with N2 from a cylinder, similarly fitted with a hose, that has a septum or membrane at the end.

Flasks would have a septum on the neck, and the balloon would vent through it, with a non-ballooned needle venting, also punched through the septum. With a cannula, liquids could also be pushed by gas pressure from one flask to another.

ahill - 14-3-2017 at 18:55

I needed to exclude oxygen for some experiments I did with tannic acid - I used argon from a bottle shop (its used to keep opened wine). The gas can comes with a thin flexible tube. If you can use a stoppable flask - great - insert the tube, then just set the stopper in the neck so that there is a small gap for the tube - dont press it in - and squirt gas - after a few seconds, remove the tube and seat the stopper. A bit of vacuum grease might be a good idea.

If you cant use a stopperable flask (say something like a beaker), just put it in a plastic bag, and apply gentle vacuum, or just squeeze - then inflate it with the argon, then zip the zip or rubber band the neck, and put the whole lot on your stirrer.

Its all going to depend how sensitive your reaction is - sometimes a little O2 is fine - the reaction just cant take being constantly exposed over a period or hours - other times - any exposure is bad. If its very sensitive - you are going to need to construct a glove box or bag.

If I search for "glove bag" on the internet, I get a lot of hits - they all look pretty expensive tho. I'd be prepared to spend a lot of time messing with washing up gloves, plastic bags and duct tape for $1000 !

I seem to remember hearing about a procedure that would be performed in a bag to which a little dry ice had been added - the dry ice would sublime, the bag would inflate and O2 would be displaced.

macckone - 14-3-2017 at 19:56

Carbon dioxide is a great displacer but some reactions are
ruined by it. Balloon helium is often contaminated with
significant oxygen to prevent hypoxia from kids breathing it.
Even iron reduction can leave enough oxygen to seriously
ruin a reaction. A/C refrigerant r134a is mostly
tetrafluoroethane with some pentane and butane added.
It will be inert a significant portion of reactions.
Propane is also an option that is readily available but
contains a sulfur compound, usually ethanethiol.
If you need absolute inertness, invest in an argon tank.
Small ones (20 cu ft) are about $99 at harbor freight.

*edited for formatting

[Edited on 15-3-2017 by macckone]

Zyklon-A - 21-3-2017 at 10:19

Quote: Originally posted by unionised

Quote: Originally posted by Zyklon-A

I know many (maybe all) helium balloons have oxygen added, ....

How do you know that?
my understanding is that it's a myth.

Hmm I looked around and you seem to be right. Not only is there no regulation that requires it, I couldn't find a single supplier who's MSDS don't warn about asphyxiation.
Probably a case of unchecked wishful thinking going mainstream. Good to know.

XeonTheMGPony - 21-3-2017 at 10:52

Quote: Originally posted by unionised

The only advantage to helium is that you can buy it from the supermarket

Due to nanny statism not any more as the helium is mixed with air!

XeonTheMGPony - 21-3-2017 at 10:56

Quote: Originally posted by Lambda-Eyde

Buy a one liter disposable tank of nitrogen or argon for welding, they are cheap enough and readily available if you know where to look. Get a suitable regulator for it, a hose and a ground glass tubing adapter and you have everything you need for a basic inert atmosphere setup. As long as this can be had so cheap there are no good reasons to be dicking around with helium, carbon dioxide, refrigerants, makeshift oxygen scavengers or canned "air" (these are actually chlorofluorocarbons, very soluble in organic solvents but mostly inert, except for being flammable).

Most caned air now days is diflouroEthan or 1,1,2 tetraflouro ethane (152a, 134a)

Those automotive over the counter ones will be 134a or a hydrocarbon blend.

134a is actually used as a fire suppressant in conjunction with R123. DiflouroEthan (152a) is flammable int he liquid state only but fairly inert as a gas.

XeonTheMGPony - 21-3-2017 at 10:59

Quote: Originally posted by unionised

Quote: Originally posted by Zyklon-A

I know many (maybe all) helium balloons have oxygen added, ....

How do you know that?
my understanding is that it's a myth.

Read the lable on the tank! not all of it is don but for over the counter to joe public it is mixed with air.

HVAC nitrogen is O2 free and dried, so for purging nitrogen get it with ACR rating

Zyklon-A - 21-3-2017 at 11:29

Quote: Originally posted by XeonTheMGPony

Due to nanny statism the helium is mixed with air!

Can you provide a reference for a company that sells such a product?
I found two relevant patents,one calls for 15-30% oxygen from 2015, the other includes oxygen and carbon dioxide, ~10% and 3% respectively. Presumably the latter is added to induce exhalation, which alone could actually be more effective than oxygen. The last thing we need is kids who think all balloons are safe to breathe freely, since they would certainly pass out before realizing the balloon came from a different company.

XeonTheMGPony - 21-3-2017 at 11:48

http://www.balloontime.com/products/products-list/

http://www.conwinonline.com/shop/60-40-helium-air-inflator/

Quote:

contain a mixture of helium and air with not less than 80 percent helium

Even using Argon and even with the OFN (Oxygen free nitrogen) I'd still use an iron O2 scavenger, or a tube coated in Cesium will effectively (Well very effectively) scavenge O2 it is used in vacuum tubes and halide lights as an O2 scavenger

[Edited on 21-3-2017 by XeonTheMGPony]

Db33 - 21-3-2017 at 12:06

its not a question of what gas to use, im just wondering how to get it from the tank into the flask and keep it there.

XeonTheMGPony - 21-3-2017 at 12:15

Well what do you have?

There are hundreds of ways to do it but depends what you got on hand and your jerry rigging skills.

I've made gas tight seals with toilet paper, Teflon tape and some capillary tube or needles.

So what do ya got.

[Edited on 21-3-2017 by XeonTheMGPony]

Db33 - 23-3-2017 at 07:50

i have a lot of flasks, 3 neck and 1 neck and some 2 neck. Round bottom and flat bottom. I plan on getting a nitrogen tank from Amazon. I also have access to various size syringes and needles if that would help, also balloons, etc...

Xeon if you can give me an example of some ways to jerry rig it id appreciate it

XeonTheMGPony - 23-3-2017 at 15:55

Ok get a nice medium bore needle, now tightly roll up some toilet paper around the needle till it is a tight fit into the flask neck, now take some Teflon tape and care fully expand it and wrap it care fully around the tissue paper till it is an even thick coat.

this will hold up plenty well for 1 to 2 runs, I used this to seal a nitric acid distillations! You can make it more permanent by soaking superglue into the tissue paper.

Opt 2 is coating a marshmallow care fully in Teflon tape as well works then driving the needle through, use some copper wire to hold it in tight for both options.

[Edited on 23-3-2017 by XeonTheMGPony]

Booze - 23-3-2017 at 18:55

Quote: Originally posted by Db33

its not a question of what gas to use, im just wondering how to get it from the tank into the flask and keep it there.

All you need to do is get the gas in and stopper it off. The rubber stopper should keep gasses from getting in pretty good.

Also, this may be a dumb question, but why do you need a nitrogen atmosphere when our atmosphere is already 70% nitrogen? Is the reaction oxygen sensitive?

clearly_not_atara - 23-3-2017 at 23:15

I think maybe a solution of copper and ascorbic acid can be used as an oxygen scrubber. Subject to degradation of ascorbate of course. Ascorbate is cheap enough that you could deoxygenate a few dozen liters of air by this method -- you just need some means to use it.

Melgar - 24-3-2017 at 01:32

My idea for a cheap and easy inert atmosphere: Get two five-gallon (20-liter) buckets, with at least one airtight lid. Fill one with water, then put your favorite oxygen/CO2 scavengers in the other. I recommend Ca(OH)2 in water for CO2, and those Hot Hands reduced-iron hand warmers, torn open, for oxygen. Now rig the lid of the bucket up so that you can have a tube coming in, that goes nearly to the bottom, and a tube going out of the top, that doesn't dangle inside the bucket at all. Check to make sure that the volume of the water plus your scavengers won't reach the outlet of the bucket. After leaving it overnight with the lid on, you can then just put the bucket of water above the bucket with the scavengers in it, and siphon water to it as you need inert gas. Use a drying tube, since there will obviously be moisture in the air, and an on/off valve to turn the inert gas on and off. The siphon will stop moving water when the pressure inside the second bucket builds up enough to counter it. Seems an easy enough to get a decent amount of inert gas.

As a bonus, you have a bucket of water in the end that you can throw a vessel into if it's releasing cyanide gas or acidic vapors unexpectedly, and have those vapors be readily neutralized.

Db33 - 25-3-2017 at 17:24

So if i was doing a 24 hour reflux... lets say in a 3 neck round bottom flask. If i stoppered 1 neck, then using a hose just flushed the entire flask with nitrogen for like 60 seconds and then stoppered the 2 side necks and had a reflux condenser on the top with some a drying tube on top of that. would that be able to keep most of the nitrogen in and the air out?

JJay - 25-3-2017 at 17:28

I think usually they would use a bubbler instead of a drying tube. It would be filled with mineral oil, sulfuric acid, or some other oil that has desirable properties and preferably won't react violently if it somehow mixes with your reaction mixture.

XeonTheMGPony - 25-3-2017 at 19:06

you need a balloon to act as a pressure buffer int hat instance, another method I fancy is to make a saturated solvent atmosphere, so what ever the most volatile part of the reaction is add a bit more Ml then pull a deep vacuum while warming and no cooling, once it starts to off gas at the top of the reflux condenser put a stopper in and turn on cooling.

This causes a deep vacuum and the only thing in it is your solvent, Naturally this depends on good sealing! and it significantly reduces the boiling temp, so if that is integral to the reaction that method won't work.

JJay - 25-3-2017 at 19:49

One of these could serve as a bubbler. You'd put just enough oil in it to prevent air from getting into the apparatus while still allowing gases from the reaction to escape. If you have a nitrogen tank, you could let gas slowly diffuse through the apparatus and exit by bubbling through the oil (I think this is called running a reaction in a "stream of nitrogen").

I don't know what your reaction is, but the balloon idea might be a good one. A little positive pressure in the apparatus would help to keep out unwanted gases and vapors. Of course, you want to make sure that your balloon doesn't get eaten up by corrosive vapors or solvents, and if the reaction produces large amounts of gases, a balloon might not be able to contain them.

XeonTheMGPony - 26-3-2017 at 04:36

JJay has an excellent point! exactly what IS the reaction, we're trying to hit the toilet in the dark here and that tends to make a mess of it!

More details the more accurate the solution can be offered.

Db33 - 26-3-2017 at 07:34

the reason the nitrogen atmosphere is needed is because the reducing agent is sodium triacetoxyborohydride, which is sensitive to water and air.

Chemetix - 27-3-2017 at 01:38

There is the Schlenk manifold option, a flask with a tap on it to evacuate and fill with N2 is the standard accessory. Jerry rigging the concept is doable for a back yarder I'd guess.

That's what they look like when set up.

[Edited on 27-3-2017 by Chemetix]

NEMO-Chemistry - 30-3-2017 at 18:01

I looked into getting Nitrogen, although in the end for me Hydrogen turned out to better.

Where I live Nitrogen didnt seem that easy or particularly cheap to get hold of, also I didnt need much. But I did find a source in the end that is probally availiable in more places than you think.

I noticed a tyre and MOT place had a sign saying, "Nitrogen tyre filling service". Now I have NO IDEA why Nitrogen is sometimes used in car tyres, but apparently it is.

So in my case I used a old small tractor, front wheel inner tube, I took it along to the tyre place and they filled up the inner tube with nitrogen for me.

Actually the guy was really cool and didnt charge me for it. Anyway in a push it might be a solution for you, I am told tyre specialist often have nitrogen to fill car tyres with.

XeonTheMGPony - 30-3-2017 at 18:28

Lol it is essentially a scam unless you're a formula 1 racer, Nitrogen expands less under the influence of temperature so the tires remain at a more constant pressure.

But it sounds exotic to your average sheeple consumer so an easy extra buck for the companies pimping it out. But good score on a way to make some real use out of that scam.

NEMO-Chemistry - 30-3-2017 at 18:34

Quote: Originally posted by XeonTheMGPony

Lol it is essentially a scam unless you're a formula 1 racer, Nitrogen expands less under the influence of temperature so the tires remain at a more constant pressure.

But it sounds exotic to your average sheeple consumer so an easy extra buck for the companies pimping it out. But good score on a way to make some real use out of that scam.

Thanks for that! I was going to get my mum to fill her tyres with it! All the guy told me was "its used for low profile, high performance tyres". Sounded kind of neat......

But yes I still have most of my nitrogen in the inner tube

. Although now I use hydrogen for my methane stuff.

XeonTheMGPony - 30-3-2017 at 20:38

Air is predominately Nitrogen! even low profile tires there is zero need for it as airs expansion is not that drastic with tires.

It is just a hilarious cash grab! Just make sure the tires have good tread and are at proper pressure and you'll be fine! and all ways fill when cold!

NEMO-Chemistry - 31-3-2017 at 02:45

Quote: Originally posted by XeonTheMGPony

Air is predominately Nitrogen! even low profile tires there is zero need for it as airs expansion is not that drastic with tires.

It is just a hilarious cash grab! Just make sure the tires have good tread and are at proper pressure and you'll be fine! and all ways fill when cold!

Funny how with most things, the more you take out, the more it costs

. I am on alot of Gluten free stuff, it costs a fortune! Same with Nitrogen, take a few other gases out of air and charge a fortune for it

.

I must go back and take a picture of the sign, it will make you laugh! The claims are many, everything from more MPG, to shorter braking distance

.

Then again the charge £2 for normal air to inflate your tyres in the garage from a machine!! If nothing else, it might help someone out with a source for small amounts and a way to transport it.

XeonTheMGPony - 31-3-2017 at 04:44

Oh we have the same garbage here, I nearly soiled my self laughing when the guy said I "should" use nitrogen for my electric car, I said ya but then I'll have to charge with lighter electricity to see any real change!

Melgar - 31-3-2017 at 04:47

Quote: Originally posted by NEMO-Chemistry

Funny how with most things, the more you take out, the more it costs

. I am on alot of Gluten free stuff, it costs a fortune! Same with Nitrogen, take a few other gases out of air and charge a fortune for it

.

I must go back and take a picture of the sign, it will make you laugh! The claims are many, everything from more MPG, to shorter braking distance

.

Then again the charge £2 for normal air to inflate your tyres in the garage from a machine!! If nothing else, it might help someone out with a source for small amounts and a way to transport it.

Technically, what they're saying is accurate. Nitrogen is slightly polar, and won't diffuse through a tire as much as oxygen does. Also, a car tire that got hot enough could theoretically pyrolyze more readily if there was oxygen diffusing through it. I mean, filling your tires with nitrogen WILL lead to an increase in all the things they mentioned; what they don't tell you is that increases will likely be on the order of 0.01%, which is hardly something that most people would notice.

The cost of stuff is usually based on how much processing has to go into it, as well as how much they can sell. Putting stuff into something is easy; taking stuff out is much harder. Any chemist who as accidentally used the wrong stir rod when doing multiple reactions at once has probably learned that the hard way.

[Edited on 3/31/17 by Melgar]

NEMO-Chemistry - 1-4-2017 at 02:59

Quote: Originally posted by XeonTheMGPony

Oh we have the same garbage here, I nearly soiled my self laughing when the guy said I "should" use nitrogen for my electric car, I said ya but then I'll have to charge with lighter electricity to see any real change!

Where do you buy your lighter electric from? I have a heavy battery for the boat, lighter electric would make moving it easier

.

Is it expensive? Couldnt find any on ebay, so I guess its banned in the UK. Maybe its some kind of precursor?

XeonTheMGPony - 1-4-2017 at 05:04

I lived off grid so I know all about heavy awkward So lets start selling helium refills for batteries! lol batteries, I just kept telling the supplier they needed to hurry up and make lead lighter too!

unionised - 1-4-2017 at 05:42

Quote: Originally posted by XeonTheMGPony

Nitrogen expands less under the influence of temperature so the tires remain at a more constant pressure.

Barely, if at all
https://en.wikipedia.org/wiki/Charles%27s_law
(and changes in the elasticity of the rubber would make a lot more difference.)

unionised - 1-4-2017 at 05:47

Quote: Originally posted by Melgar

Technically, what they're saying is accurate. Nitrogen is slightly polar,

[Edited on 3/31/17 by Melgar]

That's a clever trick for a diatomic molecule.

Hypothetically, the fact that nitrogen has more "minor" isotopes may make it true, but I'd not want to have to measure the dipole moment of the ¹⁵N¹⁴N molecule

XeonTheMGPony - 1-4-2017 at 06:10

Quote: Originally posted by unionised

Quote: Originally posted by XeonTheMGPony

Nitrogen expands less under the influence of temperature so the tires remain at a more constant pressure.

Barely, if at all
https://en.wikipedia.org/wiki/Charles%27s_law
(and changes in the elasticity of the rubber would make a lot more difference.)

Hence why it is a SCAM or did you miss that part? but people who buy into it think that's the reason to use Nitrogen, it is magical after all.

In refrigeration testing it has less pressure drift as it is OFN dry, so the pressure swing Vs temp is easily accounted for, but for a tire it is meaningless.