Convert an oxygen concentrator machine to supply 20 litres per minute of nitrogen gas?

[G50]

For the exit bag nitrogen method, I was wondering if it might be possible to convert an oxygen concentrator machine to supply nitrogen instead of oxygen. High quality oxygen concentrator machines provide around 93% purity oxygen at around 5 litres per minute, and such machines are readily available to buy online without any restrictions.

An oxygen concentrator machine works by filtering out the nitrogen and argon gases from the air, to provide high purity oxygen. Oxygen concentrators are used by people with breathing difficulties and other medical conditions. These machines are typically used in the home, and provide an inexhaustible supply of oxygen, without needing any replacement oxygen cylinders.

By my calculations (see spoiler below), if they are correct, the exhaust waste gas output from an oxygen concentrator machine will be mostly nitrogen, containing only around 1.8% oxygen. Although this 1.8% figure is based on some assumptions I made (detailed in the spoiler), and if these assumptions are not correct, then the percentage oxygen figure in the exhaust gas will be much higher (high enough to invalidate this method). So this method will only work if my assumptions are correct, and that's something that needs further investigation.

That 1.8% oxygen level, if correct though, I think will be far too low to sustain life, so if the exhaust waste gas from an oxygen concentrator machine can be tapped, then it may be a good source of nearly pure nitrogen gas for use with the exit bag nitrogen method, as detailed in the Peaceful Pill Handbook.

The advantage of an oxygen concentrator machine over a cylinder of nitrogen gas is that these machines can be bought online by the general public with no restrictions, and without raising any suspicions. Also, there is no possibility of the gas running out, as it might with a cylinder of nitrogen or helium. You can sometimes buy these machines second hand, at around half the normal price.

However, it would be necessary to open up an oxygen concentrator machine and figure out if you can tap the exhaust waste gas output, which contains the nitrogen gas. I am not sure if this is possible, or how easy this would be to do.

So this is a possible advancement on the standard exit bag method, but it needs more research. to see if it is really viable or not.


Note that there are many cheaper oxygen concentrator machines on the market, but these do not have a high enough gas flow rate for our purposes. For example, you find lots of cheap machines costing around US$300-400 which output only 1 litre per minute of 90% oxygen (and on a lower setting, might output 5 litres of 30% oxygen), but this is not enough for what we want. More expensive oxygen concentrator machines output around 5 litres per minute of >90% oxygen, and we would need this sort of flow rate for our purposes.

Spoiler: My Calculation of Nitrogen Output

The Philips Everflo, a popular high quality oxygen concentrator machine, provides 5 litres per minute of 93% oxygen.

Air contains 21% oxygen, and the rest is nitrogen, plus a 1% argon. But for ease of calculation, let's assume air is 20% oxygen, and the remaining 80% is nitrogen.

So then in 5 litres of air, you will have roughly 1 litre of oxygen, and 4 litres of nitrogen.

Now, if we assume the oxygen concentrator machine requires 5L of air to make 1L of 93% oxygen (and this is the key assumption), then when the machine processes 5L of air, we get the air divided into the high purity oxygen output, and the waste gas output, and these will contain the following amounts of oxygen and nitrogen:

Machine high purity 93% oxygen output: 0.93L oxygen + 0.07L nitrogen

Machine waste gas output: . . . . . . . . . . . 0.07L oxygen + 3.93L nitrogen
————————————————————————————————
Total: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1L oxygen + 4L nitrogen
————————————————————————————————


So the oxygen percentage in the machine's waste output will be:

100 x 0.07 / 4 = 1.8%


Since this machine outputs 5 litres of high purity (93%) oxygen per minute, and we are assuming it requires 5 litres of air to produce each 1 litre of high purity oxygen, that means the machine will draw in 25 litres of air each minute, and 20 litres of of that 25L will end up as the waste gas output.

So if this machine could be adapted to tap the waste gas output and supply nitrogen, it would supply 20 litres of nitrogen per minute, with only 1.8% oxygen in it. This flow rate is more than enough for exit bag purposes (the recommended gas flow rate for the exit bag method is 12 to 15 litres per minute).

However, we have made an assumption that the machine draws in 5 litres of air to produce each 1 litre of high purity oxygen. But if this assumption is not correct, and if oxygen concentrator machines draw in much more air to make each litre of high purity oxygen, then this whole method fails, because it would mean that there will be much higher oxygen levels in the exhaust waste gas, and so it would not be pure enough nitrogen.

I have not been able to find out how much air these machines draw in to make each litre of high purity oxygen, and if the amount is higher than my assumption, then we can throw this method in the trash.


Note that there are many cheaper oxygen concentrator machines on the market, but these do not have a high enough flow rate for our purposes. For example, you find lots of cheap machines costing around US$400 which output only 1 litre per minute of 90% oxygen, but this is not enough. More expensive machines output around 5 litres per minute of >90% oxygen, and I believe only these more expensive machines will be able to provide a sufficiently high flow rate of nitrogen for exit bag use.

 

[ClownWorld2023]

Sounds like an interesting method.

I've also thought about a variation on it.

How about using the oxygen concentrator to remove oxygen from a room instead?
Would this work with a poorly-ventilated room?

 

[Worndown]

You would need a machine built to concentrate nitrogen. I am not aware any such item.

 

[ClownWorld2023]

You would need a machine built to concentrate nitrogen. I am not aware any such item.

They do exist, but seem quite pricey.
The purity is also a bit lower than what you can get with gascylinders.

 

[idonthaveanother]

For the exit bag nitrogen method, I was wondering if it might be possible to convert an oxygen concentrator machine to supply nitrogen instead of oxygen. High quality oxygen concentrator machines provide around 93% purity oxygen at around 5 litres per minute, and such machines are readily available to buy online without any restrictions.

An oxygen concentrator machine works by filtering out the nitrogen and argon gases from the air, to provide high purity oxygen. Oxygen concentrators are used by people with breathing difficulties and other medical conditions. These machines are typically used in the home, and provide an inexhaustible supply of oxygen, without needing any replacement oxygen cylinders.

By my calculations (see spoiler below), if they are correct, the exhaust waste gas output from an oxygen concentrator machine will be mostly nitrogen, containing only around 1.8% oxygen. Although this 1.8% figure is based on some assumptions I made (detailed in the spoiler), and if these assumptions are not correct, then the percentage oxygen figure in the exhaust gas will be much higher (high enough to invalidate this method). So this method will only work if my assumptions are correct, and that's something that needs further investigation.

That 1.8% oxygen level, if correct though, I think will be far too low to sustain life, so if the exhaust waste gas from an oxygen concentrator machine can be tapped, then it may be a good source of nearly pure nitrogen gas for use with the exit bag nitrogen method, as detailed in the Peaceful Pill Handbook.

The advantage of an oxygen concentrator machine over a cylinder of nitrogen gas is that these machines can be bought online by the general public with no restrictions, and without raising any suspicions. Also, there is no possibility of the gas running out, as it might with a cylinder of nitrogen or helium. You can sometimes buy these machines second hand, at around half the normal price.

However, it would be necessary to open up an oxygen concentrator machine and figure out if you can tap the exhaust waste gas output, which contains the nitrogen gas. I am not sure if this is possible, or how easy this would be to do.

So this is a possible advancement on the standard exit bag method, but it needs more research. to see if it is really viable or not.


Note that there are many cheaper oxygen concentrator machines on the market, but these do not have a high enough gas flow rate for our purposes. For example, you find lots of cheap machines costing around US$300-400 which output only 1 litre per minute of 90% oxygen (and on a lower setting, might output 5 litres of 30% oxygen), but this is not enough for what we want. More expensive oxygen concentrator machines output around 5 litres per minute of >90% oxygen, and we would need this sort of flow rate for our purposes.

Spoiler: My Calculation of Nitrogen Output

The Philips Everflo, a popular high quality oxygen concentrator machine, provides 5 litres per minute of 93% oxygen.

Air contains 21% oxygen, and the rest is nitrogen, plus a 1% argon. But for ease of calculation, let's assume air is 20% oxygen, and the remaining 80% is nitrogen.

So then in 5 litres of air, you will have roughly 1 litre of oxygen, and 4 litres of nitrogen.

Now, if we assume the oxygen concentrator machine requires 5L of air to make 1L of 93% oxygen (and this is the key assumption), then when the machine processes 5L of air, we get the air divided into the high purity oxygen output, and the waste gas output, and these will contain the following amounts of oxygen and nitrogen:

Machine high purity 93% oxygen output: 0.93L oxygen + 0.07L nitrogen

Machine waste gas output: . . . . . . . . . . . 0.07L oxygen + 3.93L nitrogen
————————————————————————————————
Total: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1L oxygen + 4L nitrogen
————————————————————————————————


So the oxygen percentage in the machine's waste output will be:

100 x 0.07 / 4 = 1.8%


Since this machine outputs 5 litres of high purity (93%) oxygen per minute, and we are assuming it requires 5 litres of air to produce each 1 litre of high purity oxygen, that means the machine will draw in 25 litres of air each minute, and 20 litres of of that 25L will end up as the waste gas output.

So if this machine could be adapted to tap the waste gas output and supply nitrogen, it would supply 20 litres of nitrogen per minute, with only 1.8% oxygen in it. This flow rate is more than enough for exit bag purposes (the recommended gas flow rate for the exit bag method is 12 to 15 litres per minute).

However, we have made an assumption that the machine draws in 5 litres of air to produce each 1 litre of high purity oxygen. But if this assumption is not correct, and if oxygen concentrator machines draw in much more air to make each litre of high purity oxygen, then this whole method fails, because it would mean that there will be much higher oxygen levels in the exhaust waste gas, and so it would not be pure enough nitrogen.

I have not been able to find out how much air these machines draw in to make each litre of high purity oxygen, and if the amount is higher than my assumption, then we can throw this method in the trash.


Note that there are many cheaper oxygen concentrator machines on the market, but these do not have a high enough flow rate for our purposes. For example, you find lots of cheap machines costing around US$400 which output only 1 litre per minute of 90% oxygen, but this is not enough. More expensive machines output around 5 litres per minute of >90% oxygen, and I believe only these more expensive machines will be able to provide a sufficiently high flow rate of nitrogen for exit bag use.

Are you telling me I could buy a nitrogen generator for 2k on Amazon right now and ctb?

 

[ClownWorld2023]

Are you telling me I could buy a nitrogen generator for 2k on Amazon right now and ctb?

I just looked around on Amazon, but couldn't find any.
Though I think they're more expensive than 2k.

 

[idonthaveanother]

I just looked around on Amazon, but couldn't find any.
Though I think they're more expensive than 2k.

Motool technology Ak-n80 is what I found. Says the purity can get 95-99%.

 

[ClownWorld2023]

Motool technology Ak-n80 is what I found. Says the purity can get 95-99%.

I found it.

I'm concerned about the quality though, because it's made in China.

 

[idonthaveanother]

I found it.

I'm concerned about the quality though, because it's made in China.

Surely there's a way to test the purity, if one were to buy it?

 

[ClownWorld2023]

Surely there's a way to test the purity, if one were to buy it?

I myself wouldn't risk it.

I bought two ozone generator units before that were made in China.
One of them was pretty much dead on arrival, and the other one broke down after a few months of use.

I contacted the seller and they said the display might be defective and I would need to buy a replacement.
After that I gave up on it and didn't buy anything from China again, except for the elastic toggles and cord for my exit bag.

 

[idonthaveanother]

I myself wouldn't risk it.

I bought two ozone generator units before that were made in China.
One of them was pretty much dead on arrival, and the other one broke down after a few months of use.

I contacted the seller and they said the display might be defective and I would need to buy a replacement.
After that I gave up on it and didn't buy anything from China again, except for the elastic toggles and cord for my exit bag.

I'm just suggesting testing the purity of the produced nitrogen, not actually trying to ctb with it right away.

 

[ClownWorld2023]

I'm just suggesting testing the purity of the produced nitrogen, not actually trying to ctb with it right away.

You'd have to buy it first. I don't know whether they accept returns.

For that price you could buy the must luxury nitrogen SCBA/EEBD/etc. setup possible.

 

[idonthaveanother]

You'd have to buy it first. I don't know whether they accept returns.

For that price you could buy the must luxury nitrogen SCBA/EEBD/etc. setup possible.

Yeah but this seems like more of a one and done. I like that simplicity. Those setups are intimidating to me, which is why I would never do one. It's not just the actual setting up that's intimidating to me. Give me the pieces and I can do it. It's all the sourcing of parts and time it would take. No chance I'd ever do that. But that's just me.

 

[ClownWorld2023]

Yeah but this seems like more of a one and done. I like that simplicity. Those setups are intimidating to me, which is why I would never do one. It's not just the actual setting up that's intimidating to me. Give me the pieces and I can do it. It's all the sourcing of parts and time it would take. No chance I'd ever do that. But that's just me.

You can try it. Just make sure you can return it in case it doesn't work out.

For the purity testing you'd need an oxygen gas-meter.

 

[idonthaveanother]

You can try it. Just make sure you can return it in case it doesn't work out.

For the purity testing you'd need an oxygen gas-meter.

I'm not gonna do it. My rope will hold…

 

[G50]

How about using the oxygen concentrator to remove oxygen from a room instead?
Would this work with a poorly-ventilated room?

I think a room would be too large as well as too leaky to remove the oxygen using an oxygen concentrator machine.

However, what you could do is place an oxygen concentrator machine inside a very large sealed plastic bag, say large enough to hold 500 litres of air (such a bag could be made from a cube shape of 80 x 80 x 80 cm). The oxygen concentrator machine would be placed inside this bag, but the flexible tube from the oxygen output of the machine would be routed outside of the bag. That way, the machine will slowly pump out all nearly all of the oxygen from the 500 litre bag, and you would be left with just nitrogen in the bag.

You could then attach a face mask to the 500 litre bag via a breathing tube, and breathe this nitrogen, which should then work similarly to the inert gas method. Face masks used for anaesthesia are good, as the form a very tight fit to the face, using an air cushioned surround which adapts to the face. And you can buy 22 mm anaesthesia tubing which fits to these masks.

Cheap Chinese oxygen concentrator machines (costing around $300) typically pump out 1 litre of 90% oxygen per minute. In 500 litres of air, there would be 105 litres of oxygen (since oxygen is found at 21% in air). So for an oxygen concentrator pumping out 1 litre of 90% oxygen per minute (ie, 0.9 litres of oxygen per min), it would take around 105 ÷ 0.9 = 117 minutes = about 2 hours for the machine to pump nearly all of the oxygen out of the 500 litre bag.

Once the oxygen is pumped out, then you would have about 400 litres of inert nitrogen gas left in your bag. When using the inert gas method (with a bag placed over the head), they usually reckon you will need around 250 litre of nitrogen or helium in your gas tank. So 400 litres in this bag should good.

Of course, the oxygen concentrator machine might not remove all the oxygen, so there would be a residual percentage of oxygen left. Whether this would affect the results, I am not sure. Also, if you have attached a breathing mask to the 500 litre bag, your expelled breath containing CO2 will go back into that bag, which might over time raise CO2 levels to a point where it causes an issue with breathing. But given the bag has 400 litres of nitrogen, that CO2 your breathe out will be dispersed in a large volume, so hopefully would not cause issues.

 

[notwavinbutdrowning]

Interesting idea.

Are you sure the machine exhausts nitrogen? From a brief read, it seems they have a chemical bead structure inside that the inlet air passes through which absorbs nitrogen. Apparently these are called 'molecular sieve beads'.

I suppose an email to one of the manufacturers would answer it for sure.

 

[G50]

Are you sure the machine exhausts nitrogen?

I believe so.

Air only contains nitrogen 78%, oxygen 21% and argon 1%, and tiny amount of carbon dioxide at 0.04%.

So since the oxygen concentrator extracts the oxygen from the air, and supplies that in concentrated form via the oxygen outlet on the machine, the exhaust gases from the machine will be mainly nitrogen, which is an inert gas.

Oxygen concentrator machines work using the natural mineral zeolite. When air is pressurised, zeolite absorbs (or more correctly "adsorbs") the nitrogen in the air, leaving the remaining air containing mostly oxygen. That's how the oxygen is separated from the air. Then when the pressure is released, the nitrogen will come back out of the zeolite, and this nitrogen is expelled as an exhaust gas. Then the cycle begins again, with more fresh air placed under pressure, so that the nitrogen is again taken up by the zeolite.

You can actually buy room oxygen monitors starting at around $100, which will tell you the percentage oxygen in the ambient air. Such monitors could be used to check the oxygen level in the 500 litre bag.

I have a cheap Chinese oxygen concentrator which outputs 1 litre of 90% oxygen per minute, and I am going to try to set up a 500 litre bag, and see if I can create nearly pure nitrogen. If it works, I guess one lungful of that nitrogen should begin to cause a loss of consciousness. So that would be one way to test it. I will hold a mask to my face and draw in a lungful. If loss of consciousness does occur, the mask will be dropped, and consciousness regained.

One issue is that these oxygen concentrators create quite a bit of heat (the exhaust gases are pretty warm), so the nitrogen you collect might get quite hot. Although I imagine much of the heat will disperse through the thin material of the large 500 litre bag.



In the case of high-quality high-output oxygen concentrators like the Philips Everflo, which outputs 5 litres of 93% oxygen per minute, if one could possibly open the machine and tap the exhaust gas output (which will output mostly nitrogen), assuming this exhaust gas output is easy to identify and tap (when I opened up my cheap Chinese machine, it looked complex, and I could not figure out where the exhaust output was).

With the Philips Everflo, it is possible one could breathe that nitrogen output directly, since I believe the machine will be pumping out about 25 litres of nitrogen per minute (more than enough for breathing, since humans breathe about 6 litres of air per minute).

The Philips Everflo costs about $700 new, but second hand models sell for around $300.

 

[ClownWorld2023]

It's an interesting method, but sounds expensive and time-consuming to do the research.

I personally think you should aim to make this method useful by providing one or more benefits over the existing exit bag/EEBD/SCBA method.

I thought of dissipating the oxygen in a well-insulated room without ventilation, and just breathing the air directly without any other materials (plastic bag, hoses or masks) involved.

When setup properly, it could even make this method undetectable, which would definitely be a benefit that some people would consider.

I think a room would be too large as well as too leaky to remove the oxygen using an oxygen concentrator machine.

My room is one that is well-insulated and does not really have much surface where leaks can occur.

I measured the oxygen in my room once after a night's sleep. It was 19%. So I definitely think it's possible to displace all the oxygen from my room.

There have been reports of nitrogen 'spills' in other spaces with people going unconscious. These spaces were most likely less insulated and better ventilated than my room.

 

[G50]

I personally think you should aim to make this method useful by providing one or more benefits over the existing exit bag/EEBD/SCBA method.

I think for people who are not able to purchase a nitrogen cylinder for the exit bag method, this method (if it works) would be more accessible, since oxygen concentrators can be bought freely and without any suspicion.

I thought of dissipating the oxygen in a well-insulated room without ventilation, and just breathing the air directly without any other materials (plastic bag, hoses or masks) involved.

If you take a room whose dimensions are say 4 x 4 metres in floor size, and 2.5 metres high, that will contain 40,000 litres of air volume. Using the same calculation as above, it would take 156 hours = over 6 days for an oxygen concentrator to try to remove all that oxygen. Or about 24 or so hours if you used a high output oxygen concentrator like the Philips Everflo.

Even if you could completely seal the room to stop fresh oxygen getting in (which I doubt), I don't think many people would want to be waiting that long. For one thing, you would start getting altitude sickness as oxygen levels slowly dropped (symptoms like feeling sick or being sick, headache, dizziness, exhaustion). So it would be a rather unpleasant experience.

 

[ClownWorld2023]

Even if you could completely seal the room to stop fresh oxygen getting in (which I doubt), I don't think many people would want to be waiting that long. For one thing, you would start getting altitude sickness as oxygen levels slowly dropped (symptoms like feeling sick or being sick, headache, dizziness, exhaustion). So it would be a rather unpleasant experience.

It should be doable.

You would need to have a oxygen gas meter in the room to check the oxygen level. Preferably two different gas meters for redundancy.
These would need to be recorded using a video camera and then transmitted to a computer/laptop/any suitable device in another room.
You should not be in the room yourself while the oxygen concentration is being brought down.


You wait until the oxygen meters hit 0%, and then enter the room when you're ready.
The above-mentioned equipment can be removed quickly to ensure it cannot be easily detected.

If you take a room whose dimensions are say 4 x 4 metres in floor size, and 2.5 metres high, that will contain 40,000 litres of air volume. Using the same calculation as above, it would take 156 hours = over 6 days for an oxygen concentrator to try to remove all that oxygen. Or about 24 or so hours if you used a high output oxygen concentrator like the Philips Everflo.

Would it not be enough to release roughly 8500 liters of nitrogen into the room to bring the oxygen levels down to 0%? Or is it really necessary to release atleast 40,000 liters of nitrogen? (assuming 100% purity for calculation simplicity reasons)

 

[ThisIsLife]

- The cost. You would have to spend a lot more money in the end.

- The technical details: even motivated SaSu members who chose the inert gas method wouldn't go as far as reverse-engeneering this kind of machine.

- The purity: it is very important and your method suggests that you most likely wouldn't score above 99% in the best case scenario. The inert gas method is a "mechanical" method, as it works thanks to the certainty of removing all the oxygen from your environment.

With every method, simplicity is a golden rule. The less you have to do the better, because the more it gets complicated, the more room for error.
The inert gas method already requires a little bit of work to make it happen, it's not rocket science but it's not for everyone and many choose SN over it because they fear they might do something wrong.

I don't think your idea is bad, i just think it would require more money, scientific background and motivation than the existing method; but CTB methods need R&D and i'm all for innovation.