| Pages:
1
2 |
peach
Bon Vivant
Posts: 1428
Registered: 14-11-2008
Member Is Offline
Mood: No Mood
|
|
H2 is a gas you can easily buy in cylinders, why would you try to generate and compress it yourself? The cylinder companies will be able to do it far
more cost effectively. Hydrogen is used for glass blowing and welding, which are some of the main outputs for the cylinder gas manufacturers.
I would be willing to bet you could pressurize CO using a diving cylinder compressor. Provided it doesn't react with the greases or O-rings in the
compressors. Those are hundreds each, and often thousands.
You only need to generate gas when it's things like HCl, ammonia based products or SO2, which are dangerous and odd to be renting cylinders of.
Trying to generate and compress N2 or other such everyday gases is ridiculous, they're consumed everyday in vast quantities by industry, are in no way
harmful and they're cheap and dry from the cylinder companies.
[Edited on 7-7-2010 by peach]
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
i used the hcl(aqueous)/cl2 method for generating some dry HCL yesterday for the first time after reading about it here, i used a further CaCl2 bottle
as a dry tubing. Controlling was problematic until i setup up a loop whereby when not in use it was flushing down the drain, when in use it was forced
into the system via a small(~3inch) vacuum running from an aspirator with the tap water supply barely running,
i can highy recommend this method as cheap, very controllable and far better than h2so5/hcl methods for making HCL solutions for titrations etc
whereby every thing is running at a slight overpressure.
Contrary to that method in this system it doesn't matter if you get small leaks as they leak into rather than out of your system
|
|
|
peach
Bon Vivant
Posts: 1428
Registered: 14-11-2008
Member Is Offline
Mood: No Mood
|
|
Did you rent a cylinder of Cl2? If not, you were probably using a manganese dioxide Cl2 generator right? Why not just drip straight onto salt?
If I wanted to generate a large amount of hydrochloric acid, I'd use plastic containers for the HCl(g) generator; the 5l HDPE kind. I'd fill an empty
one with salt and put 'jerry can' nozzles on the outlets to connect them. Then have one full of acid above and use a tube clip between the two to
control the flow of acid onto the salt. I'd have another hole from the top of the bottom one to the top of the acid container to equalize the pressure
between the two, which could feature a Y branch to take the HCl(g) out to the water where the acid will form.
I'd do it that way because the largest flask I have is 1l, and I've had the resulting salt cake 'pop' a glass flask when I went to rinse it out.
I'm still kind of interested in the idea of condensing the HCl(g) and running it off into a 316 stainless pressure vessel. I can buy 316 nipples that
are inches long and wide and rated to 4500 psi, as well as caps and fittings of a similar kind. And I can easily line the pipe with a continuous PTFE
liner, which should make corrosion next to impossible.
The steel is well resistant alone and rated to an order of magnitude more pressure than the HCl(g) can generate.
Using the longest 316 nipple I can find with a quick google, that'd store around 2.7 moles of HCl(g).
The bastardized balance;
2.7NaCl + 1.35H2SO4 → 1.35Na2SO4 + 2.7HCl
158g NaCl, 67ml H2SO4
5p salt + 51p acid
A bigger nipple would be nice, but only if it's not on a girl.  I think my
budget can stretch a little further than that. To a long length of taper threaded 316 seamless tube perhaps.
The most difficult, or expensive, part would be controlling the flow of gas out of the vessel.
Store it in a long and thin piece of plastic (like a gutter pipe) and port that through some saturated KOH. You could stick that guttering inside
110mm drain pipe and fill the surrounding space with cement. You now have a 4500 psi, 316 pressure vessel charged to 400 psi inside a venting pipe
attached to a scrubber and that's inside a cement lined outer pipe. All cheap and easy to put together from DIY store parts and I've never seen
anyone, cylinder companies or authorities, going to that much effort.
If you filled the cement layer with cheap wire wool before pouring the cement, that'd make it even stronger (it's essentially micro-rebar and is used
in reinforced cement). There no way the pressure vessel will blow it's way through all of that at 400 psi; I've seen tanks catastrophically empty at
2300psi and only go through breeze block. The worst thing that could happen is the pressure vessel entirely fell apart and dumped all of the HCl(g)
instantly. The scrubber would be the first thing to be overloaded, not the walls.
The 316 alone would be enough, I'm just thinking of easy ways to make it even safer. I literally just threw out some of the fittings I'm talking about
and left them sitting beside a skip at the tip; 110mm fittings.
[Edited on 20-7-2010 by peach]
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
Peach, your enthusiasm and creativity are great, keep at it, this comment is not to try to stop you from thinking about things but from someone who
has tried many many things and learned over time about what potential problems will arise, without doing there is no knowing though and i'm, pretty
good these days and getting my ideas to work.
There's my justification first, now your idea has a couple of potential problems, firstly, most polymers exhibit accelerated aging under the influence
of gaseous HCL, they become brittle and fail many many times faster than attributable to normal oxidative processes. So your cylinder liner is going
to fail fairly quickly, in the order of months, however you will not notice it until the HCl has dissolved your concrete and started leaking out, then
you have a big fuck-off heavy unliftable piece of plastic and cement that one wants to go near without full respiratory and body protection.
I've posted a method for producing condensing and cylinderising Cl2, you'll find if you look, that way you can stop makign assumptions about how if
done things.
Fuck i've gotta do some work, i'll finishh my critique later.
But i just may also add that using KOH to dry HCL gas seems like a novel idea!!
edit-my mistake you're not advocating dry with KOH rather just as a safety, why not use bicarb, at least it won't chew a hole in your arm if it
sloshes around.
[Edited on 20-7-2010 by Panache]
|
|
|
| Pages:
1
2 |
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
