Natures Natrium
Hazard to Others
Posts: 163
Registered: 22-12-2004
Member Is Offline
Mood: No Mood
|
|
SO2 tank
I have some ideas for this and data to back it up, as well as some questions I could use answered. First, however, a bit of musing. 
I'm sure many here have noticed the trend for what is unusual and novel at one point in time to become expected and uninteresting in the future.
I could cite many examples, some of the most prominent and oft used ones being aluminums value and availability between 1850 and today. Anyways I was
still suprised to find that even in Vogel's 3rd, the entry for sulfur dioxide was this:
10. Sulphur dioxide. Sulphur dioxide is available in the liquid form in heavy glass cylinders ; the gas is obtained by simply turning the metal valve.
Gee thanks Mr. Vogel, do you think you could give me the latin name of the tree these glass cylinders grow on? 
Of course, on thinking about the situation, it makes sense that in Vogels, Manns, and many other even older references the availability of SO2 is
taken for granted. Chemistry, even in it's most primitive forms, has known about sulfur for a looong time. (And, in all fairness, Vogels and
Manns are not really old...only 50 years or so.) It's availability back then also makes it useful now, as many interesting reactions were
performed and detailed with the aid of SO2.
Anyways, the point is if they can do it, I can at least try and hopefully not kill myself or large tracts of vegetation in the process. 
Alright, sulfur dioxide has two physical properties of interest for my little project.
1. bp -10C
2. vapor pressure at 21.1C = 49.1 PSI (or ~2540 torr)
Ok, so I guess I should explain my plan. The idea is to generate SO2 gas and condense it at atmospheric pressure and <-10C to a liquid. The
liquid SO2 would then be poured directly into the dispensing bottle, the bottle sealed, and finally allowed to come to room temp. Given the
particular properties and uses of this chem, this does not seem unreasonable to me.
So first, I needed to find a suitable container. I'm guessing that SO2 is corrosive to metals, hence it being supplied in heavy glass cylinders.
Therfor, I came up with two viable options.
1. 2L PET pop bottle
PRO: pressures up to 100PSI ok
CON: chemical resistivity in question and
will cold (~-10C) make it brittle?
2. 750mL Champagne bottle
PRO: pressures up to 75 PSI ok
good chem resistivity
wont get brittle at -10C
CON: affixing a semi permanent valve
would be a pain in the ass
For the pop bottle, the cap could be easily modified with epoxy to have a regulator valve with a hose barb hook up. The champagne bottle would need
some sort of physical wire harness to hold it on, and the valve itself would probably need to be stuck through cork or similiar to hold it on until
epoxy could be applied to reinforce it. Really, I just like the idea of a screw on cap a LOT better than an accidental face full of SO2.  So, barring any replies with opinions to the contrary, I think the pop bottle
would be the way to go.
(ref. http://www.yobrew.co.uk/beer.htm )
So, there are two factors yet to decide upon, that of SO2 production and method of cooling said SO2.
For SO2 production, I have the following options:
1. HCl + NaHSO3 -> NaCl + H2O + SO2
2. S + O2 -> SO2
3. 4 FeS2 + 11 O2 -> 2 Fe2O3 + 8 SO2
4. 4 CuS + 6 O2 -> 4 CuO + 4 SO2
5. Cu + H2SO4 -> ??? (Ive seen this mentioned but never referenced.)
The bisulfite method is ideal in practice, except that I dont have access to large quantities of bisulfite. (I suppose I should mention I am thinking
of 4-5 mol of SO2 minimum.) I do have sulfur, but the feasability of a device to burn and capture SO2 is something I have only rudimentary ideas on.
Similiar problems abound with roasting the sulfide ores, and it should also be noted that this is an industrial process fit for arc furnaces and what
not. The sulfuric acid + copper is interesting if true, although I have my doubts. It really seems to me that this would be a good way to make
hydrogen gas. This is one part of the project that is giving me trouble, and I would really appreciate input on any aspect of it. (Ugh, damn, forgot
to jot down refs for the above reactions.  )
For cooling, I am thinking of using the ol' fallback of freezing salt mixtures. If I use NaCl (-20C) I have a graham condenser that can be used
to maximize effeciency. The downside to this is the condenser doesnt have ground glass joints, and the travel path through it is extraordinarily
narrow. Otherwise, it is my intention to use CaCl2 (-40C) and an ordinary west condenser (wrapped in insulation). The deciding factor here is
whether or not my little aquarium pump can handle these super cold water mixtures, or if it will just 'freeze up'. Also of some concern to me is whether the calcium chloride will end up clogging the
pump, although with thorough dissolution that hopefully wont be a problem. (ref http://www.sciencemadness.org/talk/viewthread.php?tid=897 and links contained therein.)
Anyways I just wanted to lay all this out here and see what sort of comments, ideas, and opinions I could garner.
Thanks,
Nature's Natrium
\"The man who does not read good books has no advantage over the man who cannot read them.\" - Mark Twain (1835-1910)
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
If you're going to condense it out, it doesn't much matter if it's mixed with a lot of air. Powdered sulfides could be roasted in a
test tube with a small tube to the bottom to blow air in (think fluidized bed). A reducing agent afterwards (powdered FeSO4?) should be provided in
case of any extra-corrosive SO3, plus some CaCl2 to dry it (unless that reacts, hmm calcium sulfite ought to be insoluble, maybe bubble it though
H2SO4 instead).
H2SO4 doesn't react with copper to my knowledge, it's too stable. HNO3 decomposes to NO2 in the process, however.
Other possibilities. Pyrotechnical sulfur or sulfide charge.
SO2 (and NH3) are useful for refrigeration and have been used as such in the past. NH3 has good reason to be unavailable in small quantities but SO2
might be around. Idunno, it seems to me even less useful than NH3 these days.
Any metals suitable for SO2? Would aluminum and iron passivate? Can iron undergo direct synthesis and make what, FeSO2?
Tim
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
There are some metals that are suitable for SO<sub>2</sub> storage, I know this because [I've said this so many times it's
rediculus ] I have some sulfur dioxide-lithium batteries that are filled with
liquid sulfur dioxide and lithium and they are made of some very shiny metal, I guess it should be easy for me to ascertain its identity. Anyway,
when you puncture them SO<sub>2</sub> sprays out and when you cut them open you can see the canister is metal all the way, no glass.
Don't know what they are made of though, probably just stainless, actually I don't see SO<sub>2</sub> being very destructive
towards many metals without water being around.
The method of reacting copper metal with sulfuric acid is the most time tested labratory method of preparation of sulfur dioxide, sulfuric acid acting
as an oxidizing agent but high temperatures must be employed:
Cu + 2H<sub>2</sub>SO<sub>4</sub> ---> CuSO<sub>4</sub> + SO<sub>2</sub> +
2H<sub>2</sub>O
Just like a normal redox reaction the sulfuric acid is reduced and the copper oxidized. It's just that high temperatures must be employed. I
remember seeing a detailed picture of the apparatus used somewhere but I cannot remember where, it's just difficult because the
SO<sub>2</sub> is generated with water so it has to be dried by running through sulfuric acid, other dessicants normally react with the
sulfur dioxide our are too weak to destroy the sulfurous acid formed.
The eucetic salt mixtures are always fun but sometimes they can be less then reliable, dry ice/acetone slurry would be best but dry ice is of course
difficult to aquire for most of the people here.
|
|
|
Marvin
National Hazard
Posts: 995
Registered: 13-10-2002
Member Is Offline
Mood: No Mood
|
|
The pop bottle is not a good choice. The champagne bottle can withstand much higher pressures but you'd have to find a chemically resistant
artificial cork. It also has the problem that its basically a poison gas grenade.
For my money pick something highly chemical resistant and low pressure but still sealed and keep the thing stored in the coldest part of a freezer
somewhere small leaks wont matter much, say in the garage. Keep the SO2 only as long as you need for the next step in whatever experiment. If you
can get dry ice, say from people that deal in ice cream supplies then storing overnight becomes fairly trivial. Do not use any sort of pump to try
pressurising the SO2 being condensed. You must have an outlet to stop fixed gasses building up. Keeping toxic high pressure gas just for the hell of
it is a mugs game, have a use planned for the following day and make it only if you need it. Run any waste gasses through concentrated sodium
hydroxide to trap SO2 with the advantage that it can be recovered at a later date.
|
|
|
IrC
International Hazard
Posts: 2710
Registered: 7-3-2005
Location: Eureka
Member Is Offline
Mood: Discovering
|
|
In the 60's I had a steel cylinder much like an acetylene tank full of sulphur dioxide. Obviously they made tanks with some kind of internal
construction which allowed the use of steel tanks. It was used to remove moisture in refrigeration systems. I know this as my family owned the largest
refrigeration business in the city I grew up in, and used the tank often. So it seems to me that these tanks should still exist somewhere, if they
could be located. Or at least the possibility exists that somwhere the information exists as to the construction of the tank itself. The one I had sat
in the shop, and then later in the garage in the hot summer as I stole it from my dad for mad science experiments. The heat of the summer never seemed
to bother it so the tank was capable of pressure. In fact it was not large, but looked and felt like it was of very strong construction. After a while
my dad realized it was missing and found me using it trying to make acid, and as I was around 10 or 11 I guess he thought I was not smart enough to
stay safe as he stole it back. Now you make me wish I had kept track of the tank over the years. In short, they did exist, so they do exist, or at
least the knowledge of how to make them is out there somewhere. I'll search around and post links here if I find anything on the subject. Since
the tank was only about 18 inches tall and 6 inches in diameter, it must have been a liquid inside as it never seemed to run dry in my experiments,
did not have a regulator yet did not seem to have a dangerously high pressure when the valve was opened. Looking at the first link I quote from below,
clearly the tank was only a steel bottle, and the SO2 was very dry.
From a company in Arizona that provides the gas: Tramfloc, Inc.
"At atmospheric temperatures and pressure, sulfur dioxide is a colorless vapor with a characteristic, pungent odor. When compressed and cooled,
sulfur dioxide forms a colorless liquid, which at atmospheric pressure boils at 14°F (-10°C) and freezes at –103.9°F (-75.5°C). Liquid sulfur
dioxide is heavier than water, having a specific gravity of 1.436 at 32°F (0°C). As a vapor, sulfur dioxide is
heavier than air, with a relative density of 2.2636 when compared to air at atmospheric pressure and a temperature of 32°F. When heated about its
critical temperature, 314.82°F (157.12°C), sulfur dioxide can only exist as a vapor regardless of pressure. Liquid sulfur dioxide exists in
equilibrium with its vapor when stored in a closed container. The vapor pressure within the container is directly proportional to the temperature,
which, when plotted, yields a smooth curve as shown in Figure 1 (I looked, could not find fig.1, obviously the page was not written by a rocket
scientist). Sulfur dioxide is somewhat soluble in water (18.59% by weight at 32°F/0°C) and forms a weak solution of sulfurous acid (H2SO3). The
degree of solubility is directly dependent on temperature (see Figure 2) (never found this one either). Generally, undiluted (dry) sulfur dioxide is
not corrosive to ordinary metals; however, when small amounts of moisture are present, sulfur dioxide will attack most metals.
Although sulfur dioxide is normally shipped and stored in liquid form, many applications require sulfur dioxide to be supplied as a vapor. Due to the
inherently low vapor pressure of sulfur dioxide, vaporization of the liquid requires heat, which must be supplied to the cylinders from an external
source. Electric strip heaters or steam coils equipped with thermostatic control are generally used for this purpose. Because fusible safety devices
in the cylinders melt at 165°F (74°C), great care must be taken not to allow cylinders to exceed (125°F (51.7°C).
PS: I remember my dad telling me the way it worked was after pumping down the system, some SO2 gas was run through, and any moisture present turned
into acid which attacked the condensing tube walls, thereby taking itself out of the system, but not enough etching to harm the tubing. After this the
system was pumped down again, and was quite dry internally. I mention this as it seems that if your steel cylinder was of strong construction and your
So2 did not contain much moisture, it would solve its own problems without harming the strength of the tank walls. If it was very moist this could
become a problem though. So in short dry the SO2 before you liquify it and a steel tank should be good enough. As to using a propane tank I am not
sure if the walls are thick enough, and do not know how the pressure safety would act with SO2. The walls were very thick in the tank I had so this
could be important.
[Edited on 22-6-2005 by IrC]
|
|
|
Mr. Wizard
International Hazard
Posts: 1042
Registered: 30-3-2003
Member Is Offline
Mood: No Mood
|
|
I have an old 'lecture bottle' of SO2 that has had liquid in it for over 40 years. It is about the size of a wine bottle, but not as wide, 5
or 6 cm. It is steel with a brass valve. SO2 was used a long time ago as a refrigerant. If steel and brass don't corrode under dry SO2, why not
use an old Propane tank? It will certainly stand the pressure. The only question is to the dryness of the gas, and to make sure the safety blow off
valve in the tank isn't some fusible alloy that can be eaten away by the SO2.
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Alrighty 
So who wants to donate their air compressor to the cause? It would be easiest to either fill a tank with 80PSI of sulfurous gas, cool and pour off
the liquid to another container and let it warm up (and develop its room temperature pressure), or condense it with the dry ice stuff and drip that
directly into the (also cold) tank.
Both involve a lot of cooling, but you don't need as much with compression.
Besides dehydrators, think you could throw some silica gel in the tank? Or maybe a sacrificial ball of steel wool whose large surface area gets
attacked preferentially to the tank?
Tim
|
|
|
Natures Natrium
Hazard to Others
Posts: 163
Registered: 22-12-2004
Member Is Offline
Mood: No Mood
|
|
Good info
Ok, I think things are coming together. On further contemplation both the ideas of pop bottles and champagne bottles filled with pressurized
poisonous gas raised the hair on tha back of my neck. Finding out that absolutely dry SO2 is safe to store in stainless steel cylinders is great news
and definetly helps a lot. Now I can procure a container designed to store and despense pressurized gas in the first place. 
As for method of creating SO2, I have found an OTC product that contains 20-60% metabisulfite. The problem is the remainder of the product is sodium
hydrosulfite (dithionite).
Na2S2O4 + 2HCl -> H2S2O4 + 2NaCl ???
I dont know, I havent been able to come up with a reaction scheme that makes sense both logically and intuitively. It is stated in the Merck that
hydrosulfite undergoes oxidation when wet or solvated in water to a mixture of bisulfite and bisulfate, but it doesnt really state reaction rate or
which way the equilibrium leans. Mainly I want to go with the acid/bisulfite method of production because its a very easy set up and endothermic to
boot. If it becomes necessary I think heating sulfur in a current of oxygen is doable, as long as the reaction speed can be controlled by limiting
the amount of O2 available. I still like the Cu + H2SO4 method, but without details such as reaction conditions it cannot be considered a viable
alternative.
Ive got a saturated solution of CaCl2 cooling in the freezer as I type, to check if my pump can handle the cold temps.
If someone could help me with the dithionite reaction scheme it would be most appreciated. (As is all the replies I have recieved so far regarding
this endeavor.)
Oh, and not to single you out Marvin, but know that your cautionary warning I do take serious and I appreciate your concern. However, if I only made
it when I needed it, why bother to go through the trouble of condensing it and storing it in the first place? The idea is in fact to have a bottle of
pressurized poison gas sitting around for use should I need it at any given point. I hope you can see where I am coming from on this, and I just
wanted you to know that I wasn't blatently ignoring your statements. Of course, I do have multiple expieriments planned which require the
introduction and use of SO2, thus my interest.
UPDATE: By some good fortune, I stumbled upon a perfect vessel. It is one of those old oxygen tanks for industrial use (think oxy-acetylene), and it
measures 33cm from top of neck to bottom and is roughly 8cm in diameter. It is made of some extremely thick metal (looks to be 1/4" thick walls
of stainless steel), as it was designed to hold up to ~2000 PSI. It came with a simple twist valve that I have yet to inspect for use, although I may
replace it with a standard brass regulator anyway so that I can monitor the pressure inside the bottle at all times. (Haven't seen the inside of
the bottle either.) Super sweet.
[Edited on 22-6-2005 by Natures Natrium]
\"The man who does not read good books has no advantage over the man who cannot read them.\" - Mark Twain (1835-1910)
|
|
|
Lambda
National Hazard
Posts: 566
Registered: 15-4-2005
Location: Netherlands
Member Is Offline
Mood: Euforic Online
|
|
CO2 gas-cylinder as SO2 container
Allthough not made up of 316 stainless steel or Alloy 20, it may be a suitible container for SO2. In hobby-stores, they sell disposible CO2 cylinders
made up of, I assume a low grade carbon- steel for MIG-welding. In MIG-welding, CO2 is used as a protective blanket when welding steel. These
cylinders, have a hight of 30 cm and are 7 cm wide. The pressure rating on this cylinder is 190 bar. The empty weight being 1080 grams, and having a
volume of 950 ml. My cylinder code is: EUROTRE A19-B17-50/99-02-1-120 and contains 390 grams of liquid CO2.
Apparently, if dry, SO2 should not be problematic in respect to reactivity with steel.
| Quote: | | Please, do not fill these cylinders with gunpowder, somebody may get hurt !
|
|
|
|
BromicAcid
International Hazard
Posts: 3227
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
When I wrote my post to this thread I had some site in mind where they discussed the preparation of SO<sub>2</sub> but I couldn't for
the life of me remember the address, but I just did, enjoy, also has some interesting information on hyposulfurous acid.
Hyposulfurous Acid
And be sure to check out their archives as there seems to be at least one chemistry experiment per issue or some interesting lab technique.
[Edited on 6/25/2005 by BromicAcid]
|
|
|
Natures Natrium
Hazard to Others
Posts: 163
Registered: 22-12-2004
Member Is Offline
Mood: No Mood
|
|
Well, I did it.
For better or worse, and hopefully death won't make me part, I did it.
I attempted to condense the gas as I stated above, with a CaCl2 salt bath, but I could not get the temperature below -18C. Decided that wasn't
going to be nearly good enough, so I went ahead and bought a block of dry ice and threw it in the cooler where I had my set up arranged. Of course,
the ineveitable happened, and the mix froze up enough (at a little below -20C) to stop my little aquarium pump. ( I did manage to collect a few mL of
SO2 before the pump froze.)
So, after doing some quick thinking and rearranging of my setup, I ended up directing the gaseous SO2 directly into a 500mL RBF submerged to the neck
in an acetone/dry ice bath. This proved to be suprisingly effecient, to the point that the bubbler on the end of the apparatus rarely was disturbed.
Ok, to recap I dropped HCl(aq) on a mixture of sodium dithionite and sodium bisulfite (an unknown porportion of the two) to generate SO2 gas which was
led through a claisen adapter and then a rubber hose to a glass tube leading down to the bottom of a 500mL RBF submerged in an acetone/dry ice bath.
I managed to acquire >250mL of SO2 liquid, which equates to roughly 5.86mol. Not nearly as much as I was hoping for (I was looking for 400mL or
9.38mol), but still not too bad. The entire thing, start to finish (after initial set up) took about eight hours. The cylinder is currently being
stored in the freezer ( I dont have the time yet to let it come to room temp and see if it holds properly).
One odd note is that a by product of this method of SO2 production is a lrage quantity of what appears to be elemental sulfur. I am saving it, and
will attempt to recrystalize it from hot toluene. If it is indeed raw sulfur, I think I just got an extra 300-500g of S. My only guess is that perhaps H2S was being formed from the dithionite and was immeadiatly reacting with the large amount of SO2 present to form water
and S.
Some time soon I will do the cuprous chloride formation test to verify that I do indeed have SO2, although I have to admit I am pretty sure of myself.
EDIT: PostScript
I forgot to say thanks to everyone who helped out! Thank you!
Also, I want to say I am damn glad I didnt try to bootleg a 2L pop bottle or champagne bottle, I have this stuff behind 1/4" thick stainless
steel and I'm still nervous about it. (5.86mol = 131 cubic Liters @ 1 ATM
= horrible mess and/or painful death. )
[Edited on 27-6-2005 by Natures Natrium]
[Edited on 27-6-2005 by Natures Natrium]
\"The man who does not read good books has no advantage over the man who cannot read them.\" - Mark Twain (1835-1910)
|
|
|
jimwig
Hazard to Others
Posts: 215
Registered: 17-5-2003
Location: the sunny south
Member Is Offline
Mood: No Mood
|
|
17 different lab generated gases here including SO2.
http://mattson.creighton.edu/SO2/index.h
tml
|
|
|
neutrino
International Hazard
Posts: 1583
Registered: 20-8-2004
Location: USA
Member Is Offline
Mood: oscillating
|
|
That link is broken. It should be .html.
|
|
|
Natures Natrium
Hazard to Others
Posts: 163
Registered: 22-12-2004
Member Is Offline
Mood: No Mood
|
|
Oh yea.
Well, the SO2 tank is holding up nicely. I was able to reduce a solution of cupric chloride to cuprous chloride using SO2, although I accidently left
the rinsed salt out and exposed to atmosphere where it appeared to dissociate into a mixture of CuCl2 and Cu powder. The tank itself works like a
charm, I feel so professional having a "lecture bottle" at my disposal.
Btw, I forgot to mention that the SO2 collected was a clear, fuming liquid.
Also, the yellow crystalline powder is not elemental sulfur. I tried heating some in an 80mL beaker, and at 150C it still would not melt. It did
however appear to oxidize and go from sulfur yellow to a brownish color. Im not sure if I am going to try and ID it or just toss it. I would hazard
a guess that it is sodium sulfide from the Mercks description of the compound, except that it is not reactive towards a strong mineral acid like HCl.
It is also fairly insoluble in water and acetone. Hmm, I just don't know.
\"The man who does not read good books has no advantage over the man who cannot read them.\" - Mark Twain (1835-1910)
|
|
|
chloric1
International Hazard
Posts: 1070
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
Bisulfites
Today while I am waiting for my tricalcium phosphate to dry, I decided to try a novel approach to obtaining SO2. I tried heating sodium metabisulfite
in a test tube with a propane torch. Everything at first seemd to go as planned but in a matter of seconds the salt darkened and a rotten egg odor
followed the SO2 smell and sulfur is sublimed on the walls of the test tube
Apparantly I heated too hot and the bisulfite was reduced in a SO2 atmosphere to polysulfudes and sulfur. Next time I will add some water to moderate
heating or sodium sulfate to keep down reduction. I got the idea from the book "Synthetic Inorganic Chemistry" | Quote: | Originally posted by Natures Natrium
I have some ideas for this and data to back it up, as well as some questions I could use answered. First, however, a bit of musing.
I'm sure many here have noticed the trend for what is unusual and novel at one point in time to become expected and uninteresting in the future.
I could cite many examples, some of the most prominent and oft used ones being aluminums value and availability between 1850 and today. Anyways I was
still suprised to find that even in Vogel's 3rd, the entry for sulfur dioxide was this:
10. Sulphur dioxide. Sulphur dioxide is available in the liquid form in heavy glass cylinders ; the gas is obtained by simply turning the metal valve.
Gee thanks Mr. Vogel, do you think you could give me the latin name of the tree these glass cylinders grow on?
Of course, on thinking about the situation, it makes sense that in Vogels, Manns, and many other even older references the availability of SO2 is
taken for granted. Chemistry, even in it's most primitive forms, has known about sulfur for a looong time. (And, in all fairness, Vogels and
Manns are not really old...only 50 years or so.) It's availability back then also makes it useful now, as many interesting reactions were
performed and detailed with the aid of SO2.
Anyways, the point is if they can do it, I can at least try and hopefully not kill myself or large tracts of vegetation in the process.
Alright, sulfur dioxide has two physical properties of interest for my little project.
1. bp -10C
2. vapor pressure at 21.1C = 49.1 PSI (or ~2540 torr)
Ok, so I guess I should explain my plan. The idea is to generate SO2 gas and condense it at atmospheric pressure and <-10C to a liquid. The
liquid SO2 would then be poured directly into the dispensing bottle, the bottle sealed, and finally allowed to come to room temp. Given the
particular properties and uses of this chem, this does not seem unreasonable to me.
So first, I needed to find a suitable container. I'm guessing that SO2 is corrosive to metals, hence it being supplied in heavy glass cylinders.
Therfor, I came up with two viable options.
1. 2L PET pop bottle
PRO: pressures up to 100PSI ok
CON: chemical resistivity in question and
will cold (~-10C) make it brittle?
2. 750mL Champagne bottle
PRO: pressures up to 75 PSI ok
good chem resistivity
wont get brittle at -10C
CON: affixing a semi permanent valve
would be a pain in the ass
For the pop bottle, the cap could be easily modified with epoxy to have a regulator valve with a hose barb hook up. The champagne bottle would need
some sort of physical wire harness to hold it on, and the valve itself would probably need to be stuck through cork or similiar to hold it on until
epoxy could be applied to reinforce it. Really, I just like the idea of a screw on cap a LOT better than an accidental face full of SO2. So, barring any replies with opinions to the contrary, I think the pop bottle
would be the way to go.
(ref. http://www.yobrew.co.uk/beer.htm )
So, there are two factors yet to decide upon, that of SO2 production and method of cooling said SO2.
For SO2 production, I have the following options:
1. HCl + NaHSO3 -> NaCl + H2O + SO2
2. S + O2 -> SO2
3. 4 FeS2 + 11 O2 -> 2 Fe2O3 + 8 SO2
4. 4 CuS + 6 O2 -> 4 CuO + 4 SO2
5. Cu + H2SO4 -> ??? (Ive seen this mentioned but never referenced.)
The bisulfite method is ideal in practice, except that I dont have access to large quantities of bisulfite. (I suppose I should mention I am thinking
of 4-5 mol of SO2 minimum.) I do have sulfur, but the feasability of a device to burn and capture SO2 is something I have only rudimentary ideas on.
Similiar problems abound with roasting the sulfide ores, and it should also be noted that this is an industrial process fit for arc furnaces and what
not. The sulfuric acid + copper is interesting if true, although I have my doubts. It really seems to me that this would be a good way to make
hydrogen gas. This is one part of the project that is giving me trouble, and I would really appreciate input on any aspect of it. (Ugh, damn, forgot
to jot down refs for the above reactions. )
For cooling, I am thinking of using the ol' fallback of freezing salt mixtures. If I use NaCl (-20C) I have a graham condenser that can be used
to maximize effeciency. The downside to this is the condenser doesnt have ground glass joints, and the travel path through it is extraordinarily
narrow. Otherwise, it is my intention to use CaCl2 (-40C) and an ordinary west condenser (wrapped in insulation). The deciding factor here is
whether or not my little aquarium pump can handle these super cold water mixtures, or if it will just 'freeze up'. Also of some concern to me is whether the calcium chloride will end up clogging the
pump, although with thorough dissolution that hopefully wont be a problem. (ref http://www.sciencemadness.org/talk/viewthread.php?tid=897 and links contained therein.)
Anyways I just wanted to lay all this out here and see what sort of comments, ideas, and opinions I could garner.
Thanks,
Nature's Natrium |
[Edited on 7/5/2005 by chloric1]
Fellow molecular manipulator
|
|
|
unionised
International Hazard
Posts: 5102
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
Did that very long quote serve a purpose?
|
|
|
chloric1
International Hazard
Posts: 1070
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
No not really except to demonstrate that I was on the bisulfite topic. I did not realize it was that long. I was distracted at this time.
Fellow molecular manipulator
|
|
|
AndrewShirley
Harmless
Posts: 1
Registered: 6-9-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Lambda
Allthough not made up of 316 stainless steel or Alloy 20, it may be a suitible container for SO2. In hobby-stores, they sell disposible CO2 cylinders
made up of, I assume a low grade carbon- steel for MIG-welding. In MIG-welding, CO2 is used as a protective blanket when welding steel. These
cylinders, have a hight of 30 cm and are 7 cm wide. The pressure rating on this cylinder is 190 bar. The empty weight being 1080 grams, and having a
volume of 950 ml. My cylinder code is: EUROTRE A19-B17-50/99-02-1-120 and contains 390 grams of liquid CO2.
Apparently, if dry, SO2 should not be problematic in respect to reactivity with steel.
| Quote: | | Please, do not fill these cylinders with gunpowder, somebody may get hurt !
|
|
Hi There,
Please can you let me know where i will be able to purchase EUROTRE A19-B17-50/99-02-1-120 as described above. i would be looking to buy approximately
a few hundred.
If you know can you please e-mail me at andrewshirley@abbeychart.co.uk
I look forward to your help
Andrew
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
