Sciencemadness Discussion Board

Help improving the process

sodium_stearate - 20-4-2014 at 14:29

Hello,

Please forgive this double posting. I can't figure out any
other way to get my request for possible suggestions
or help up on top so people can see it.

This is in reference to my other topic about
"Making Edison Cylinder Records".

In short, it involves saponifying stearic acid with NaOH.
I am looking for ways to make a condensor/separator
to recover the stearic which normally boils away.

Please see my other post, scroll to the bottom.
I have a link to a video that shows how I'm doing it
now.

Thanks!!

thesmug - 20-4-2014 at 14:40

Feed it through a tube into a flask in a cold or ice water bath.

HgDinis25 - 20-4-2014 at 14:55

You coud lead it through a tube directly into could water. Stearic Acid has a very low solubility in water (3 mg/L (20 °C)).
And where's your other post? There's no link...

sodium_stearate - 20-4-2014 at 14:55

Thanks for that suggestion. One consideration there would
be to manage the temperature in the tube somehow
so that the stearic would stay liquid, thus somehow then
being returned to the main vessel, maybe dripping back
down in there.

Meanwhile the water vapor condenses and drains away.
I've given this considerable thought, and it's not a real
simple thing.

Ideally, the entire process could be sealed. But then it
starts getting complicated because it needs to be looked
at, stirred, and caustic solution added slowly, portionwise.

thesmug - 20-4-2014 at 15:02

You've just described a reflux! Search "Reflux" on Wikipedia for more help! It also cannot be sealed, the pressure will make it explode.

sodium_stearate - 20-4-2014 at 15:06

Here's the link:

http://youtu.be/LrR9h9fu324

and thanks again smug!:cool:

Yes, I know the steam pressure would build up if
it were sealed, and that's been a part of my thinking about this
for a long while now. Some pressure would probably
benefit the process, but it would need to be controlled
to a set pressure by some sort of a relief or safety valve.

thesmug - 20-4-2014 at 15:44

You're welcome!