Hello, I am having trouble with my solvent recovery setup. I have attached some pictures and as you can see, the temp in the boiling flask is 78C. Prior to this, i had it set to 80C, where it was constantly hovering around 77C. Isn’t ethanol suppose to boil off at 154F/ ~67C? My temp gun showed that my heating mantle’s temp accuracy is about +6-7 degrees off the digital temp display, but that’s still about 159F/71C. Why is it only then do I see ethanol dripping into my boiling flask?
Just yesterday I had my setup running and was able to achieve some solvent recovery at 72C, which if my heating mantles display is truly inaccurate, would be ~66C, or 150F. That is 4 degrees under the boiling temp of ethanol right? What gives then…
My vacuum pump is one I made using Nalgene Water Vacuum Aspirator and a Superior Utility pump. It’s not great right now because it heats up fast but I’m going to alter its design to make up for that tomorrow. I have attached pictures of it as well.
As for my main issue, why isn’t my ethanol boiling off under vacuum until 70-72C? This seems a bit high, no?