Author Topic: dcm distillation from paint stripper in the can  (Read 5215 times)

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carcrash

  • Guest
dcm distillation from paint stripper in the can
« on: December 10, 2002, 02:33:00 PM »
Distilling right out of the can rocks. Drill a 3/8 inch hole in a stopper that fits the can snuggly. Fit a 3 foot piece of high density 3/8 inch poly ethlene tubing into the stopper.  Stopper the can, place it into a warm water bath.  Do not boil the water. Run the tube down into the bottom of a 1 gallon jug of distilled water that is sitting in a cooler full of ice water. When the can has room add a pint  or 2 of water and slosh it around some. The water gets displaced from the jug into the cooler as it fills with distilate.  The jug in the ice bath and the 3 foot length of tubing act as the condensor.

This is not super fast but can run unattended, does not mess up your glassware and also does not tie up your glassware. Just make sure you have a decent amount of water in the water bath before you take off.

Afterwords shake up the gallon jug of water/methanol/dcm. With a seperatory funnel seperate off the bottom dcm layer.

1/4 inch tubing does not work.  Surgical tubing does not work well, the dcm attacks it. Use a store bought 1 gallon water jug, or some other hdpe plastic to distill into.

I know the idea of distilling out of the can has been mentioned before. Turning it into a fool proof write up any non chemist can follow was my main purpose.   

Yield is about 99 percent of the dcm content - anything you spill.

Dcm spills evaporate incredibly fast.

Not a chemist I just follow directions on the box mix

majic22

  • Guest
let me make sure i have this straight.
« Reply #1 on: December 11, 2002, 10:14:00 PM »
let me make sure i have this straight.  the 3 foot 3/8" tube runs out the top of the stripper can straight over into a gallon jug already containing distilled water sitting in an ice bath?  so the distillate comes over an mixes with the distilled water in the gallon jug and in the end you have distilled water and dcm/methanol mixture in the gallon jug??  then shake the gallon jug and pure dcm falls to the bottom?  is that correct?

Theres nothing to be afraid of, just concentrate, and trust the music.

carcrash

  • Guest
Exactly
« Reply #2 on: December 11, 2002, 11:42:00 PM »
The dcm fills up the jug forming the bottom layer. Having the jug full of distilled water when you start cools the distilled dcm, weighs down the jug in the ice bath and is used for washing the dcm afterwords. Also the water layer holds down the dcm so that it does not evaporate off. Water is added to the stripper can after some has been distilled off to keep things from getting too viscous though it may not be needed and also to weigh the can down so it does not float on top of the hot water bath.  Most of the methonal goes into the water layer which overflows out of the jug as dcm displaces the water. Shaking the jug well afterwords is to wash out any traces of methanol or other distilates that came across and are still in the dcm layer. The methanol goes into the water.

If using a stripper with acetone and toluene I am pretty sure they will float on top of the water layer, though I recommend a gel stripper with just dcm and methanol.

The 1/4 inch tubing does not run right because then you get drops of distillate that clog the tube and quadruple the distillation time. 3/8 inch tubing works much faster and does not get clogged by drops of distillate. Bigger tubing is not needed, too stiff and the stopper size limits using anything much bigger. Too stiff could cause a problem of the stopper being pulled out of the stripper can.

About 5 to 6 hours to distill a gallon of stripper. But if this runs for 24 hours nothing will be hurt as long as the hot water bath does not all evaporate and the icebath is still cool.

Not a chemist I just follow directions on the box mix

majic22

  • Guest
good......swim will try this tonight....thanks
« Reply #3 on: December 12, 2002, 03:29:00 PM »
good......swim will try this tonight....thanks

Theres nothing to be afraid of, just concentrate, and trust the music.

majic22

  • Guest
i think i successfully came up with dcm.....
« Reply #4 on: December 12, 2002, 09:46:00 PM »
i think i successfully came up with dcm.....heres how it went.

when i first set the gallon can of stripper into the warm water....the water was about 60 deg C.....after a few min it went down to 50 deg and i held it steady at about 45 deg for the duration of the distillation.   when it was all over i shook up the distillate and when it settled the bottom layer which should be my pure dcm was collected using a sep funnel.....the dcm has a slight yellowish tint to it and has a very strong odor....it smells like dcm.....is it supposed to be the slight yellowish color?  i think i was successful but just want to double check. 

Theres nothing to be afraid of, just concentrate, and trust the music.

carcrash

  • Guest
Mine was about the color of water
« Reply #5 on: December 12, 2002, 11:03:00 PM »
Though it is a bit less translucent than water.  Were you using a gel stripper made of dcm and methonal? Some of the other gels have more ingrediants. I am unsure of what would cause the yellowness. Stripper that came in a gold can worked great. Spotted at 2 different hardware store chains. If this is considered giving a source let me know so I can edit that out.

At this point if all else fails do a normal distillation or maybe try washing it again. Redistilling the purifried dcm should be very fast and not muck up your glassware. Suspecting the yellow may be maybe a hint of acetone or toluene that was in a stripper brand that was not just gel, methonal and dcm. Spill a little and see if it evaporates completely cleanly in no time flat.

Not a chemist I just follow directions on the box mix

majic22

  • Guest
the stripper is said to contain methylene ...
« Reply #6 on: December 13, 2002, 03:04:00 PM »
the stripper is said to contain methylene chloride, methanol, and toulene.  it is a popular brand super-st**. it was a semi gel type stuff.   is this an ok brand to use?  i will try washing again and post results...

Theres nothing to be afraid of, just concentrate, and trust the music.

carcrash

  • Guest
Find a stripper with just dcm and methonal
« Reply #7 on: December 13, 2002, 03:39:00 PM »
The yellow hint is obviosly toluene. However unless unless a trace of toluene is a problem you can use it as is.

Not a chemist I just follow directions on the box mix

majic22

  • Guest
toulene has a boiling point of 110.63 deg C.
« Reply #8 on: December 13, 2002, 03:49:00 PM »
toulene has a boiling point of 110.63 deg C.  are you sure thats what is producing the yellow?  because the temp never went over 60-65 deg C?????

Theres nothing to be afraid of, just concentrate, and trust the music.

hCiLdOdUeDn

  • Guest
If your using that blue colored stripper, which ...
« Reply #9 on: December 13, 2002, 04:01:00 PM »
If your using that blue colored stripper, which contains DCM, methanol, and toluene, Then you will only get back ~20% DCM. It sucks. This is because those three compounds forms an azeotrope with each other and the distillate contains DCM, methanol, and toluene. Once you wash it with water, then the DCM will have ~30-40% toluene in it. Once you wash the methanol out then its possible to distill to get DCM.

My advice...Find a better stripper. There are some gel type ones out there that is 85% DCM with NO methanol.

Sink or SWIM

carcrash

  • Guest
Aye
« Reply #10 on: December 13, 2002, 04:05:00 PM »
Using a stripper 83 percent dcm rest methonal and gel crapola.  Works perfectly.

Not a chemist I just follow directions on the box mix

wyndowlicker

  • Guest
Very Nice!
« Reply #11 on: December 15, 2002, 09:12:00 PM »
very nice,simple way to do this.Ive been using glass unecessarily.My original post on the subject was nice,but this is better.Im gonna get right on that as well. :P

Come to daddy on an inside string,and I guess theres no chance of loosing this time.-GD

majic22

  • Guest
ok
« Reply #12 on: December 27, 2002, 10:38:00 PM »
ok i finally got around to distilling the yellowish colored crap i got from the can distillation but something weird happened....  heres how my setup worked..

-simple distillation setup (no vacuum)  had ice water circulating through condensor
-heating mantle for heat and stir plate to stir.

-I wrapped the top half of my rxn flask with aluminum foil to insulate.  I had the thermometer in the still head in proper position, and then i had a second thermometer in between the mantle and bottom of rxn flask (so i could tell the temperature differences)  the weird part is this.....

I had the stirrer on slow stir and heated up the mantle and it took forever to heat up but it finally did, When the liquid started coming over, the temperature in the still head thermometer read 27 deg C....this made me wonder what was going on because the boiling point of methylene chloride is 39.8...WTF?  i turned the stir control up and the temperature went up....to about 35 deg C but it never seemed to go over that......can someone explain what happened.....i am almost positive that i now have fairly pure methylene chloride because there is no yellow color and i put a drop on the table and sure enough, it dried up right away just like dcm is supposed to.

raffike

  • Guest
DCM
« Reply #13 on: December 28, 2002, 03:04:00 AM »
We have DCM paint strippers in Europe too.Called Paint Stripper and label says contains methylene chloride and less than 10% methanol.

LaBTop

  • Guest
Possible answers:
« Reply #14 on: December 28, 2002, 05:00:00 PM »
1. You were distilling an azeotropic mix of DCM+Methanol(+ godknowswhat).
2. You were initially distilling at such a slow rate, that the small amount of DCM condensated on the bottom of your stillhead thermometer, and while evaporating back into the rest of the stillhead, took away so much energy from your mercury in the thermometer, that you got a wrong, lower reading of the DCM vapours, passing too slowly by the thermometer.
3. A combo of 1+2. LT/

PS: washing your raw DCM mix with clean water first, then separating (in a separator funnel) from the mix that water which will have taken up any possible amounts of methanol and other water soluble polutants, will spare you from nr 1. and 3.
DCM will not mix with water.