We keep the pump in really good repair, always checking and changing the oil, etc.
I’ll look into a bigger vac, thanks for the advice - i’d love to get below 100 microns during the run. EVERY run.
Distillation speeds are 2 to 3 hours on the body. I think I mentioned above now that the vacuum is lower we’re getting better temperature ranges too. Cannabinoids at 170 to 220 (never above 220).
It has just one thermoprobe for the mantle (chinese) that came with the setup. I have two kangaroos on the condenser heads for vapor temp.
Do you have you have a thermometer for measuring temperature in the still head and another thermometer inside the boiling flask?
Keeping your pump in good shape is a must for low vacuum depths but the fact that your ultimate vacuum depth is variable between runs suggests either something to do with the composition of the crude, a small leak in the system, or perhaps that due to the larger heating mantle and boiling flask vapors are being produced faster than your pump is able to pump them out of the flask.
Either way look into getting a big Edwards for your big boy spd. Also hit up @david and get a quote for a collection flask isolator so you can eliminate a potential leak point from the extra glass joint connection on the cow adapters.
CO2 crude can be acidic, I believe that it must be extracted sub-critically to make a great starting crude from CO2.
If you can, I think it might be a good idea to make some crude by soaking how you normally would, then only filter through T-5, then through a glass frit filter, but if you are sure that you are setting your T-5 filter correctly (making a slurry and pouring the ethanol through it over and over) you shouldnt have to. Then winterize, recover, decarb and distill. You will get some gunk in your boiling flask that will be a pain, but you can test the disty and see if you are still getting isomerization. Then you can scrub and degum your first pass distillate how you like, before your second pass. With so many variables, its hard to narrow it down.
Like @ScoobyDoobie said, you are going to want 40 or more CFM for your 10L setup.
Thanks for the advice and reading through. I am sure that we’re setting the bed correctly and the process that you described is essentially what we’ve been doing. Our degum process didn’t use the brine wash method, just the water/winterization method so there shouldn’t have been much pH issues to worry about. We were concerned it was the acidity of the CO2 crude especially since the results were so horrible but I did test the pH of everything and nothing showed as concerning.
Ya i’m looking at getting a larger pump now. Thanks!
Well that’s good, because I was going to suggest you run a few brine washes on a solution of heptane and your crude to bring the ph back to neutral before you put it in the boiling flask.
Also I missed the fact that your using co2 crude, so carbonic acid formation could be contributing to the problem. Co2 reacts with water to form carbonic acid, and could be a possible source of isomerization.
Right. I understand that as well and the same goes for the filter aides getting through the bed… I tested the pH multiple ways and it seemed right. Also, the amount of isomerization doesn’t add up from others that i’ve read that have dealt with carbonic acid from CO2 extraction processes. At least to me anyways.
