Anyone using a Solvent Recycler to recycle dirty IPA for reuse?


#1

A buddy of mine sent me this link: https://solvent-recycler.com/ for a solvent recycling machine. Basically it’s a still with a refrigerator unit to cool the vapor and collect clean IPA. Single-button operation. Just dump in the dirty solvent, seal the lid, hit a button and come back later to retrieve the fresh IPA and remove the plastic bag full of resin (which could be put in the sun to cure and then dispose).

This manufacturer quoted me around $3800 for the unit. There are other manufacturers of such machines but I have not found a better price for the capacity. It’s a mature technology that has found application in various industries that use solvents such as automotive painting.

Thinking about recycling the IPA, instead of using and disposing of it, which is a pain. For the amount of IPA we use I am thinking the machine would pay for itself fairly quickly.

A bonus could be having fresh IPA for each form-wash load instead of running it until it gets dirty enough to change out.

Would such a machine work for recycling TPM or DPM, I wonder. Darnit Jim I’m an engineer not a chemist. Any chemists feel free to chime in.


#2

I believe that there are solvent degreasing or cleaning machines that have a heated sump to hold the solvent. The evaporated solvent rises into the upper section, condenses, and then drips over the item to be cleaned and drains back into the sump. That might be an interesting approach to cleaned resin parts so long as the solvent gets into all the nooks and crannies.

So far as TPM and DPM go, a search for their vapor pressures and boiling points and comparing that data to IPA might be instructive. Probably best to just call the solvent recycling machine maker and ask them.


#3

I have 2 home stills that I use to recycle IPA. I just run one at a time. Only cost $100 on eBay and work great. I do have a large barrel type container for water that is recirculated to cool the IPA. I can do about a gallon and a half an hour.

Never have had the plastic bags work in the still. As they get burnt to the bottom and break of course. I used the baking bags that are supposed to take 400+ degrees. So, I have to do a bit of scraping but it’s cheaper than disposal through a service.


#4

I have one of those stills from Amazon. Have been reluctant to try it with IPA, concerned about explosion. Will probably set it up outside far from anything valuable and give it a shot.


#5

I use fire to recycle my IPA in our driveway. That way I get some entertainment value out of it.


#6

There’s little to no explosion threat. Keep the temperature to just the level that it produces output. I use a digital electric heater that I set the wattage on and that does it. I’ve been doing this for over 3 years with no issues.
I run it on a screen porch at the back of the house or sometimes in the garage. Keeping the water tank cool is the biggest issue but so far that hasn’t cause any problems. I’ve distilled maybe 200 gallons of IPA this way.


#7

Ran a batch through the still this afternoon. Distilled out a gallon. Did not explode. Started with dirty 91% IPA. Wondering if distillation makes it 99% now?


#8

Look up azeotrope and isoproyl alcohol - you should 91% IPA in your distillate assuming that it was saturated with moisture to begin with. You can get a drier IPA if you run your distillate through a molecular sieve. The mol sieve will need to be regenerated periodically to remove the moisture that has been absorbed.


#9

#10

I found this one, which seems to also come in an approximately Form Wash sized model (12 litres). Appears to be the same sort of appliance, using a disposable bag for the residue.

https://abe.co.nz/product/solvent-recycler-15l/

Didn’t get a chance to call them today for a price, will report back.