Sciencemadness Discussion Board

Ethylene Glycol from Antifreeze

digga - 21-1-2021 at 14:51

For short money I got a gallon of no-name undiluted antifreeze from Wal-Mart. Set up a multi-neck 500 ml flask and Liebig condenser. Used a pottery shard as a boiling stone. Ran the heating mantle full bore and insulated the works with folded aluminum foil strips. All the EG comes of first. The adulterants all boil higher. So far I have distilled off a couple of liters. Rather than boiling near to dryness I added 200 ml periodically through an available neck using a powder funnel. When I added each aliquot, the distillation would cease and I could change the receiving flask before the product came over once again.

After having processed 2 liters or so, the contaminants had built up to the point where there was a lot of foaming, which spoiled one lot. What remained in the flask was goopy and clearly polymerized. I discarded it in the organic waste jar, gave the flask a rough and ready cleaning and put it back in play with the spoiled lot being reprocessed.

It is my intention to process the entire gallon, and take a goodly part of it and produce several hundred milliliters of 1,4 dioxane. The product is clear and somewhat viscous. It is miscible with water.

Incidentally, I had tried to set up a steady state process with a pressure equalizing addition funnel and found that the extra volume made distillation more difficult. Had I a short path apparatus, I would have used it.

[Edited on 21-1-2021 by digga]

monolithic - 21-1-2021 at 16:13

I made some 1,4-dioxane from Walmart antifreeze not too long ago. Here's a short writeup: https://www.sciencemadness.org/whisper/viewthread.php?tid=84... I recommend storage over BHT to prevent peroxide formation. You can buy it for cheap on eBay or Amazon.

digga - 21-1-2021 at 17:03

That takes all the fun out of ether prep. You never know if some peroxide has sublimed its way into the cap's screw threads. A trope in many chem departments is finding old student prep ether while changing buildings. Hello bomb squad my old friend...

rockyit98 - 21-1-2021 at 22:41

what is the concentration of diluted and direct to tank Antifreeze? at least density? i asked around and one pound of pure Ethylene Glycol is the same price as gallon of diluted and direct to tank Antifreeze.

UC235 - 22-1-2021 at 18:06

Even the "concentrate" antifreeze contains some water. Be sure to discard the forerun. There's also usually some diethylene glycol (no problem if you're making dioxane), dye, and fatty acid salt sodium 2-ethyl hexanoate seems common and is the reason for foam.