497 - 12-1-2008 at 20:57
Today i attempted to make some sulfurous acid. The setup was: cut off aluminum pop can to contain the sulfur, the pop can inside a mason, pure O2
piped in through a small steel tube supplied from and oxy-acetylene torch, SO2 piped out with rubber vacuum tube and bubbled through water.
The sulfur was low grade garden sulfur, full of clay and other crap. I added maybe 50 grams of this to the pop can, set it in the jar, turned on the
O2 flow, lit the sulfur and quickly screwed the lid on.
It started out fine, bubbled away happily into about 800 ml cold water, but soon it started getting hot, hot enough to vaporise the sulfur which lead
to sulfur condensing in the hose plugging it. Also a pretty red film of sulfur on the glass. Fortunately the rubber seal on the mason jar lid had been
burned off when we soldered the tubes on, so it just spewed SO2 and sulfur gas out of the seal.
Not too long after that the glass broke as you can see in the picture. The can had slid against the side of the jar heating it a little too much... I
turned off the O2 and it went out. After it had cooled i found that there was very little sulfur left in the can, it would have gone out soon on its
own.
Next time i have a go at this i'll definitely use an all metal setup. Still not sure about how i'll keep the sulfur vapor at bay..
I'm planning on trying the freeze/thaw treatment on the H2SO3 to see if i get any H2SO4. I think there's a possible yield of 285 g/L, not bad.
Fun little experiment anyhow, even if it was -20F outside.
Thoughts on improvement? Comments?
YT2095 - 13-1-2008 at 02:42
Why did you use pure O2?
I use a simple fish tank air pump for mine and I`ve Never had that problem.
vulture - 13-1-2008 at 05:30
You're not gonna have any H2SO4 as you miss the catalyst for producing SO3. Furthermore, standard glass isn't up to those temperatures and will crack.
12AX7 - 13-1-2008 at 05:32
Ummmm go slower? 
YT2095 - 13-1-2008 at 06:03
if the "freeze Thaw" process doesn`t work try putting some H2O2 in the water you collect the SO2 in.
497 - 13-1-2008 at 13:19
yeah, i'm going to try air next time i think. and yes i know the glass wasn't a good idea, but i wanted too be able to see what was was going on
inside. Prototype #2 will be out of 4 or 5 inch pipe. I want one with maybe a kilogram capacity, bubbling it into a 5 gallon bucket. Thanks for the
H2O2 idea, i'll have to try that (i'm lucky enough to have 5 gallons of 50% H2O2.) And as far as running less O2 goes, I couldn't really have turned
it down much, the valve on the torch is not meant to be set so low. Thanks for the input, i hope i'll have to for the next try soon.
[Edited on 13-1-2008 by 497]