Sciencemadness Discussion Board

H2SO4 distilation wont condense

Sandman3232 - 27-11-2017 at 09:26

So today i wanted to distill some sulfuric acid from draincleaner. I started it in a sand bath with about 2cm of sand between the bottom of the heat source and the RBF. When the sulfuric acid started to boil white smoke came over in the condenser but it wouldn't condense and only ran straight trough the condenser and out the other side. It worked the previous time with the same drain cleaner from the same exact bottle? Any ideas?


[Edited on 27-11-2017 by Sandman3232]

Vosoryx - 27-11-2017 at 09:33

Was the apparatus under vacuum?

JJay - 27-11-2017 at 09:45

I've seen that before... I'm pretty sure it is water vapor and/or decomposition products from the inhibitor. It's nothing you want to breath, but I wouldn't worry too much about it. If you keep going, the sulfuric acid will start to condense.

I personally have had too many accidents with sand baths to use them for that purpose, and it may be hard to get enough heat through the sand bath to distill at a decent rate. I would recommend a heating mantle.

Sandman3232 - 27-11-2017 at 09:47

No it was at atmospheric pressure. Both times. Although the previous time it was in the RB Flask on a heating mantle that couldnt quite reach boiling temp and the next day i took it and distilled it on something that could get to the temp

Sandman3232 - 27-11-2017 at 09:51

Jjay that might be it. The previous time i noticed the blackish inhibitors burnt to the side of the flask but this time it is just gone. I turned it off and the completely black liquid has now turned to a water clear substance

Vosoryx - 27-11-2017 at 09:55

I haven't experienced that, but i dont have a ton of practice on distillation of sulphuric.
I use a heating mantle. I found sandbath's to be too unreliable a long time ago.

JJay - 27-11-2017 at 10:03

Some people have used heating tapes and home-built furnaces. This video shows sulfuric acid distilled in borosilicate using a 380 watt heating mantle: https://www.youtube.com/watch?v=4DUGRWjdNLI


This is a flask that I designed for distilling sulfuric acid: https://www.ebay.com/itm/500ml-Customized-Quartz-Distilling-... It's quartz, so it can be heated with a direct flame. I usually use it with a 3000 watt propane burner. That would be very dangerous with a borosilicate flask, but quartz can easily handle temperatures and temperature changes that would liquify or shatter borosilicate. The seller is Donghai Yukang Quartz Material direct.



[Edited on 27-11-2017 by JJay]

hissingnoise - 28-11-2017 at 03:43

Quote: Originally posted by Sandman3232  
Jjay that might be it. The previous time i noticed the blackish inhibitors burnt to the side of the flask but this time it is just gone. I turned it off and the completely black liquid has now turned to a water clear substance.

Hot, concentrated H2SO4 is a potent oxidiser and will easily remove most organic contaminents, but "completely black" is exaggeration, surely?

JJay - 28-11-2017 at 04:32

I doubt it... I've seen light yellow drain cleaner turn black when heated... further heating causes it to clear up....

Some brands are black before they are even heated: https://www.youtube.com/watch?v=8mSH-yFofA8

elementcollector1 - 28-11-2017 at 05:03

I have one of those 'completely black' brands. If you want to get technical, dilution reveals it to in fact be a very, very dark brown in coloration. Still, it's for all intents and purposes a pure black liquid. I've been meaning to purify it, but school's been whacking me with a sledgehammer lately...

JJay - 28-11-2017 at 05:16

The blackest substance known... but even it only absorbs 99.965% of visible radiation....

https://en.wikipedia.org/wiki/Vantablack

Bert - 28-11-2017 at 05:45

I have used the "black acid" before, actually used it to open drains.

Supplier said it was leftover materials from an electroplating factory. And it sometimes ate holes in old Iron waste pipes anyhow.
Quote: Originally posted by JJay  
The blackest substance known... but even it only absorbs 99.965% of visible radiation....

https://en.wikipedia.org/wiki/Vantablack


Apparently, a substance which causes black humor?
Quote:

During a talk at the Denver Art Museum, Semple casually responded that his release of an ultra-fluorescent pink he had developed would not be allowed to be purchased by Kapoor. He later released a strong shade of pink with a non-binding disclaimer that Anish Kapoor was not allowed to purchase.[18][19] He later stated that the move was itself like performance art and that he did not anticipate the amount of attention it received.[20] In December 2016, Kapoor posted an Instagram post of his middle finger dipped in Semple's pink.[21] Semple has also produced a colour-changing paint and cherry-scented deep black coloured paint that Kapoor is barred from purchasing in a similar fashion.[22][23] The company Nanolab partnered with Boston artist Jason Chase and released a colour called Singularity Black, with ongoing research and development efforts directed towards the arts community.


Yep, a singular showing, the gallery turned into a black hole.

golon - 28-11-2017 at 16:29

Might have something to do with the inhibitors they add to protect the plumbing. You could try adding some H2O2 very slowly. This creates a dilute solution of peroxymonosulfuric acid which destroys the inhibitors. The drain cleaner I buy comes with pink inhibitors in solution, and when I add the peroxide is slowly becomes colorless.

Sandman3232 - 29-11-2017 at 00:44

I was thinking of ading H2O2 and then distill afterwards too. Or might just burn the shit out of those inhibitors. I think buying h2so4 is what im going to in the future though because this distillation is becomming an irritation.

ave369 - 3-12-2017 at 13:13

How long was your condenser? My 30 cm Liebig combined with the nose of the distillation retort proved quite adequate for H2SO4 distilling. All of the "white genie" was safely condensed.

[Edited on 3-12-2017 by ave369]

aga - 3-12-2017 at 13:43

A sand bath has only ever been annoying in my experience.

A direct flame always worked better.

Now i have some decent sulphuric acid, no longer do i have to boil brown stuff like crazy.

When i did, i added 3% H2O2 when the acid was very hot, with stirring, an the brown disappeared immediately.

Acid-to-water-just-like-you-oughta is basically a lie.