Sciencemadness Discussion Board - Idea for bottling chlorine...

Idea for bottling chlorine...

evil_lurker - 24-7-2006 at 14:16

Lately I have been wanting to bottle some chlorine, but was having a bunch of trouble coming up with suitable containers to use as cylinders. I believe I may have found a working solution, or at least somthing that will hold a chlorine gas safely for at least a day or two.

The paintball hobby has brought with it many diffrent options for storing various gasses such as CO2, N2, and compressed air. Due to the need for plentiful gas storage tanks, it is now possible to purchase a cheap 12oz steel CO2 tank off the net for around $20 including shipping. These tanks are supplied with a brass pin valve which is designed to be somewhat easily removed from the tank in case of malfunction or damage to the threads. Initial testing in a soak of standard 10 molar HCl seems to have little effect on them (no visible fizzing). Replacement valves can be had for $5-7 or less, depending on where you find them.

For dispensing the gas, they make what is called a "bottom fill adapter" which screws onto the pin valve. These come in anodized aluminum flavors (not good, but would probably work at least for several hours as long as the chlorine is cool and very dry) and have a 1/8" NPT port for attaching a hose from which a needle valve and/or hose barb may be attached. These are cheap too, running around $10 each, with a whole fill assembly running around $35-40 after shipping.

As a safety device, they make anodized aluminum caps for the pin valvs, which a think layer of rubber between it and the cap would hold the chlorine in case of valve failure, again temporarily.

Think these tanks would work as a short term solution for storage up to 48 hours?

hodges - 24-7-2006 at 14:44

One interesting way to store chlorine is as the hydrate. I once made some chlorine in a 1 liter plastic pop bottle using Ca(OCl)2 and HCl. I calculated the amounts I would need to get 1 liter of gas and added this much of the chemicals to the bottle. I put the top on the bottle loosly and let it fill up with chlorine (do this outside!). When the reaction was over I screwed the top on all the way. I then inverted the bottle under water and squeezed out the reactants. I sucked in a small amount of water, shook, and then also squeezed this out under water. I let in some pure water from another container.

I then chilled the bottle in the refrigerator, with occasional shaking. The bottle collapsed, and yellow slushy crystals of chlorine hydrate formed in the water. I was able to take the bottle out of the refrigerator and watch as the solution slowly "boiled" and the bottle inflated again. I repeated several times.

Chlorine did not appear to attack the plastic bottle at all (unlike when I tried making bromine and it ate through the plastic).

Here is a picture:

Hodges

not_important - 24-7-2006 at 14:50

The chlorine is going to need to be real dry, like 100 ppm or less of water.

Chlorine will directly react with metals below hydrogen in the electromotive series, ie metals that don't 'fizz' with aqueous non-oxidizing acids will still get chewed up by elemental chlorine.

I think you'd do better with a Dewar of dry ice + ethanol, just keep the chlorine below -34C or so. Should be able to keep that for a couple of days.

You need to hold roughly 7 to 10 bar, you might be able to use glass bottles that held 'sparkling drinks'. Take a wooden box some cm taller than the bottle, pour 10 cm of sand in the bottom, set a pliece of PVC drain pipe upright, pour sand around the pipe until the box is full. Keep the bottled chlorine inside the pipe, in a cool but well ventilated area.

not_important - 24-7-2006 at 14:55

Hydrate works, especially if wet Cl2 will be OK. When you're taking the Cl2 out, add salt to reduce the solubility of the chlorine in the water; or (quickly) transfer the hydrate to a flask that you can warm to drive off the dissolved chlorine.

Note that the chlorine will slowly be attacking the water, it's still a short term storage.

Mr. Wizard - 24-7-2006 at 15:10

Storing Chlorine made at home in steel tanks is a bad idea unless you can get ALL the water out of the Chlorine. Any water will form a corrosive that will quickly eat through steel. We are talking minutes not hours.

Even dry Chlorine will attack steel at over 80*C and actually burn producing brown smoke. I wasn't able to find a reference to this on the net, but I remember seeing a video about chlorine safety and thinking it was even below the boiling point of water. Has anyone else got the number. I know it was very low, and a burning steel pipe produced clouds of brown smoke.

Nick F - 24-7-2006 at 15:23

Has anyone ever made any liquid chlorine? I was thinking about making some and ampouling it next time I get some dry ice, it'd be pretty neat, and I reckon if the ampoule was small and thick-walled it'd easily be up to the job. And if the ampoule had a long neck it'd be easy to melt it closed while still keeping the bulb cold.

It'd certainly be cooler than gaseous chlorine as a sample in my element collection.

So, anyone tried it? Any pictures?

The_Davster - 24-7-2006 at 15:33

No pictures, I collected about half a ml by leading dry chlorine into a testtube in dryice/acetone bath. Had to stop as I was doing this in my basement, and all the chlorine was not condensing.

evil_lurker - 24-7-2006 at 15:46

The idea was to use HCl + KMn04 followed by running it thru a drierite drying column followed by two concentrated sulfuric acid wash bottles and into the bottle sitting in a acetone/dry ice bath. The drierite alone should be able to get it down to a -70C dewpoint and the sulfuric acid should hopefully be able to take care of the rest.

The only catch is the bottle would have to be open to the atmosphere though to allow for any HCl and O2 to escape.

When the bottle is filled to about halfway or so the valve would be reinstalled and stored in the deep freezer at -10C until ready for use, and then kept in an ice bath during use.

Rosco Bodine - 24-7-2006 at 16:14

A lecture bottle , or other small commercial bottle
would probably be the best way to go . Chlorine
is a dangerous material to be handling with any
uncertainties , unless you have no other option .

Fleaker - 24-7-2006 at 17:05

I'd look around for a stainless steel bottle if possible, or as Rosco mentioned, and old lecture bottle. Evil lurker--you will definitely have it dry enough if you follow that drying procedure

I should perhaps try and liquify chlorine as a sample since I have a teflon-clad pump capable of pressurizing to 135 psig and ready access to dry ice and LN2. I could probably use a bottle from my hydrogenator, they are good to 120 psig. Well, add this to my list of useless but dangerous things I need to get around to doing :\

For clarity, I should mention that those hydrogenator bottles are themselves clear.

[Edited on 26-7-2006 by Fleaker]

ethan_c - 25-7-2006 at 00:42

Quote:

Originally posted by Fleaker
I should perhaps try and liquify chlorine as a sample since I have a teflon-clad pump capable of pressurizing to 135 psig and ready access to dry ice and LN2. I could probably use a bottle from my hydrogenator, they are goot to 120 psig. Well, add this to my list of useless but dangerous things I need to get around to doing :\

Chlorine liquefies at room temperature around 110 psi I think, I saw a sample in a thick quartz vial somewhere. Make sure ees very, very dry…

I don't see why anyone with an element collection would want to keep Cl, liquid or gas, in a steel or otherwise metal container. Don't you want to SEE the bloody stuff?

neutrino - 25-7-2006 at 06:58

Is there any reason it would have to be super-dry if stored in a glass ampoule? HCl generally doesn't corrode glass all that well. Maybe the following reaction would occur and raise the pressure inside the vial:

Cl2 + H2O --> HCl + ½ O2

ethan_c - 25-7-2006 at 12:16

Quote:

Originally posted by neutrino
Is there any reason it would have to be super-dry if stored in a glass ampoule? HCl generally doesn't corrode glass all that well. Maybe the following reaction would occur and raise the pressure inside the vial:

Cl2 + H2O --> HCl + ½ O2

If you remember that the vial is under 7.6whatever atmospheres of pressure, the reaction equilibrium will very much favor the right side. Pressure wouldn't be raised, but the more trace water in the vial, the more Cl you would lose to colorless impurities, diluting your overall sample.
It's not really a safety issue in the vial, but its something one would want to consider if one wants a fairly pure sample.

Also, I would be more worried about the pressurized HCl munching away at the valve or any metal tube/regulator being used to pressurize the gas to put in the sample, assuming it's not coming straight out of a tank.

tumadre - 2-9-2006 at 21:28

Quote:

Originally posted by ethan_c
Chlorine liquefies at room temperature around 110 psi I think, I saw a sample in a thick quartz vial somewhere. Make sure ees very, very dry…

are you for certain, I have been holding off on producing sodium, calcium, and manganese from the chlorides,

In the amounts I am interested in producing the chlorine gas would be produced in the hundreds of liters.

The CL2 would have O2 and N2 mixed in with it, so would using a 300psi pump and a chilled tank work by stopping the pump at 300psi, and letting off the O2 and N2 until say 130 psi?

running the excess O2/N2 through a CL2 absorption system after,

and conc. SA before the pressurization to remove water

also, a vacuum pump configured backwards.... would the seals hold?

or should I use a fridge compressor

not_important - 2-9-2006 at 23:26

Hundreds of liters? And what safety precautions are you taking?

Any ordinary pump is likely to be trashed by pumping chlorine, especially if it is not absolutely dry.

If you can get liquid nitrogen, use it to freeze out the chlorine, then pull a vacuum on the frozen Cl2 for a brief time to remove other gases. Then let it warm up to dry ice temperature, while closed off under vacuum.

If you can't get LN2, then use dry ice, and pump off for a rather short time.

In either case, if using a mechanical pump you will want some traps to keep Cl2 and HCl out of the pump.

Dewars are your friend for this sort of thing, as are Dewar condensers. Good ventilation is useful.

You can the pour the liquid chlorine into the pre-cooled (dry ice temperatures) storage vessels, leaving behind moisture as ice. Seal it up, pressure will be generated as it warms up. If the container fails under pressure, not only will you have the bomb-effect with flying bits of container, but the added fun of a cloud of chlorine gas. Be sure to invite your friends in advance.

[Edited on 3-9-2006 by not_important]

evil_lurker - 3-9-2006 at 08:18

I went to Airgas the other day and inquired on the purchase of a cylinder of chlorine.

Best I can recall an 8X32" size 80 cylinder would run like $148 for the contents, and around $200-300 for the cylinder, or it could be rented for a monthly fee.

Don't know exactly how much is in it, but I can guarantee its waaaay more than I would need.

tumadre - 3-9-2006 at 21:03

the problem is... what to do with the chlorine gas.

what if I were to use a tank with a diafram in it, like the water-air tank in your well, fill the rubber with CL2 until full, and pressurize the air side until the CL2 condenses into a tank at near 0 C

this CL2 would be from a castner cell, so I can't make it all at once and bottle at -100 C

the process needs to be smooth and continous

I am sure I can get all the water, HCL out, but not the O2 and N2
there is not much O2 and N2, like 1% or less

safety? includes storing the bottles in the ground and in a second sealed container,
later the CL2 can be transfered to a cheaper glass container and disposed of in the bay

not_important - 4-9-2006 at 09:12

Chlorine attacks many unsaturated organics such as rubber, you'll need to pick a material that isn't bothered by the chlorine.

You could try reading up on liquid chlorine handling, then prowl the surplus and second hand market to pick up the needed equipment.

Condensation is continuous, you just need a goodly supply of dry ice or LN2.

You could try the chlorine hydrate route for temporary capture and concentration, then in batch mode clean up the Cl2 and store it.

Eclectic - 4-9-2006 at 12:22

Surely USING the chlorine as it is produced to make something would be a safer option? Hypochlorates, chlorates? Aluminum chloride? If all you care about is disposal, a tower packed with wet iron turnings ought to make a good scrubber, as it seems to work to capture and concentrate bromine from the electrolysis of sea water.

tumadre - 4-9-2006 at 21:07

to clear things up,

I am interested in disposing of a large amount of gas in a cheap way

producing CCL4 or Chlorafoam is cost effective from say propane

all this is if my castner cell gets off the ground, and at 150 amps, a large amount of cl2 requires a large amount of iron, aluminum, Naoh, Caoh etc.

150 amps = about 5.6 moles/hour= 198 grams CL2 /hour

to be cost effective I would run the cell for like 24 hours at a run, (I'm not working at this time)

realized later that 5 moles per hour is about 70 liters of gas/hour.
don't take these numbers too seriously, if I doubled the current it would not make a difference as to the amount of work it would be to set all this up

[Edited on 5-9-2006 by tumadre]

Eclectic - 5-9-2006 at 06:30

Brake drum and rotor turnings from an auto shop are free...
Hydrated Lime is cheap in 50lb bags from a farm supply.

not_important - 6-9-2006 at 05:48

For a run of only a day, and if you want to save the chlorine, then condensing it to later be transfered to storage vessels, is practical. As the chlorine from the cell is going to be fairly dry, you should be able to give it a polishing dry with silica gel and feed that into the condenser; the low temperature from the LN2 or dry ice will finish the drying. Precool the gas with a tube cooled by ice-water, to take a liitle load off the final cooling.

If you just want to trap the Cl2 in a less toxic form for later disposal, the the wet scrap iron way would work fairly well. A couple of 'towers' made from plasic drain pipe, hooked in series, with a trickle of water feed in the top of each.