Help please? Volatiles in hemp extract compromising my vacuum :(

Yeah, folks around these parts generally won’t touch biomass below 10 or even 12%.

Are the terpenes worth the trouble from this strain?!?

Are those numbers based on input vs output? Or do you also have coas on the spent material?

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The steam distillation is not negotiable sadly.
The advantage is though that I don’t have to be concerned about terps in the rest of the process :wink:

I have hybridised this strain for several years with high terp strains to give me the cultivation benefits of the CBG monster while yielding yummy terps.

I am well aware that it is the iso extract process that brings the problem compound into it. But i am limited in what I can use as the primary extraction solvent. Heptane is not an option as the main solvent. However it could be used in smaller amounts in a clean up stage. Maybe that is something I need to pursue. It’s becoming obvious that my problem is unique so probably strain related as I’ve seen others use the same process without dramas on other strains. I am actually growing another strain this year to confirm this.

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There are some quite elaborate crude cleanup rituals posted here. None that I’ve performed on a regular basis.

Pretty sure the steam step first isn’t making the task easier

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The time depends on your crude. I would use your small vacuum and start at 80C and slowly ramp up to 130C. After that set up your cold trap (if not already) and use your strong vacuum pump to pull off the volitiles from 130-150C. If full vacuum is applied and your at 150C and no bubbles appear then you known your ready for distillation. Keep the vacuum applied and allow it to cool to 100C. Take apart your glassware and dry it. Then assemble for distillation.

Have you tried a LLE to get rid of residual water solubles?

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Cleaning ritual #23

Where's that degumming thread, Future?

I miss @circus_animal

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Those higher yield strains push over our legal THC limits due to our climate. They also tend to fail as a crop.

Yes, the terpenes are definitely worth the trouble. I have spent over 5 years improving them so they are a bit different than the original.

Yes, I always analyse all parts so I have a total and know where the goodies are.

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Even though I have pretty much done this many times before I decided to follow your instructions exactly. Sadly with the same result. When the flask reaches 180C a rapid evolution of gases compromises the vacuum. I held it at 180C for 4 hours until the evolution stopped and vacuum went below 100 mic again, but when I then edge it up to 190 the bubbles start again.
I know what you describe is how it is supposed to be as I have seen others work with different strains. It’s just not how it is happening for me.

I noticed my resin has a very low pH. Less than 4. Is that normal? This is before winterisation and decarb but seems to be a little lower after decarb. And by pH I mean if I wash the resin with an equal amount of distilled water, the water will have that pH.

I am wondering if the steam distillation process my material undergoes creates some carboxylic acids? eg via the hydrolysis of esters. I would have though these carboxylic acids would decarb at below 150C but maybe I am wrong.
My next attempt will be with material that has been washed to neutral. I’d prefer to avoid washing with alkaline because the emulsions take days to break, but a couple of water washes would be easy.

The other thing I noticed is that the burnt stink that evolves at 180-200C are phenols, probably cresol. I’ve produced enough of this to actually distill it off as a separate fraction :roll_eyes: That’s why everything smells and tastes of creosote. Any idea what generates cresol at those temps?

If your vacuum is low (below 300 micron) and all of your joints are sealed properly then the reason the gasses are increasing is you are hitting your main body fraction. Are you using your main roughing pump at 180C-190C? If so whats your pump model? It almost sounds like you dont have enough vacuum CFM and the CBD vapors are causing a spike in vacuum.

Whats the model of your pump?

Where are you taking temp and vacuum readings?

I’ll ask again how much water you have in your isopropanol…

this strikes me as bizarre and unlikely (not that it is happening necessarily but that it is more ‘volatiles’)

my thinking is in line with what @FranzVon has said.

the vapor pressure associated with the lites you would come to expect to be in there would not allow them to hang out indefinitely until you increase the temp by a few degrees and suddenly youre off gassing a ton of volatiles, which seems to be what you are suggesting.

water would make your system behave as such, quite awful to have in your system when youre trying to pull deep vacuum, except that i would expect youd be encountering problems at much lower temperatures.

take your crude up to 160c and pull vacuum. volatilize a few mL of your head fraction to be sure. once youre actively pulling over cannabinoids there should not be anything in there popping and killing your vacuum.

i realize my comment doesnt really offer much. you sound like you are equipped to figure this out though.

interesting

my IPA is 99.9%, so water content is less than 0.1%
I don’t reuse any until I have this problem solved.

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I don’t think it is the main body fraction causing this as the second distillation does not cause this issue. And distilling pure isolate does not cause it either. I mean, yes there is a slight drop in vacuum, but no more than 50 micron. No comparison to the 500 to 5000 micron I lose on first pass.

I have used both my large cheapo 11 cfm pump and my Edwards RV12 at this temp. The only difference is that the cheapo starts at >300 micron while the RV12 starts at <50 micron.

Probe in flask, mercury thermometer in head, vacuum at cold trap.

This is all well above the temps where water is present.

take your crude up to 160c and pull vacuum. volatilize a few mL of your head fraction to be sure. once youre actively pulling over cannabinoids there should not be anything in there popping and killing your vacuum

Yes, and that’s exactly how it behaves on second pass. As expected. But not on first.
Today I stopped heating 1/3rd of the way through the main fraction for a few minutes. The vacuum recovered very quickly. Then I started heating again and it rapidly started producing volatiles again. I stopped at 1/3rd because this is only faintly stinky and I swapped the receiving flask out. The rest then came over very stinky burnt with the vacuum quickly going up to 800 micron (from 70 at 100C).
From all my observations I can guarantee that a volatile is being produced continuously at >180C.

Today’s lot had been additionally winterized with dry ice and had water and alkaline washes. It seemed to improve things as the stink in the first 3rd was much less than usual and vacuum held for longer than usual, but the final 2/3rds were as bad as ever.

That’s what I initially thought, but I am quickly running out of ideas.

huh. definitely bizarre. ive not and dont know anyone who has dealt with a molecule with massive vapor pressure hiding out among the various cannabinoids (their volatile temp ranges i mean)

whats your vacuum protection like? are you rocking a sufficient cold trap?

sounds like its time to collect whatever this mystery compound is

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cold trap makes no difference to this problem other than keeping my pump oil clean. with trap (ice or dry ice) or without (remember I don’t have terpenes or anything else that’s steam volatile in my material). The volatiles produced come across alongside a deep red/brown condensable (likely cresol). The actual volatile is very likely CO2. I am thinking of sacrificing some material to run at 1atm and collecting the gas. But I am not sure that will really help me.

Your whole process is convoluted. It should be simplified. Also you need jump and assy pumps in arrays. The reason why you are having issues is prob hardware related.

Great the process like a remediation. You can’t get answers unless you physically eliminate the issue.

One good way is by doing a extraction, remove terps or bypass step. So directly to a water wash and use mixed phs and rid the fluids of everything. Begin your process. If that doesn’t solve it then you’ll need to do a coulm effort and start physically stripping. Then try to distill. If your probs are solved you prob has co extracts present.

what’s convoluted about it? It’s standard IPA extraction, double winterization, filtration, decarb (or decarb before winterization), devolatilisation, and SPD. Just like everyone else is doing.
Everything else I have mentioned is just additional processes to elucidate the problem.

The only thing i do different to others is that my biomass is already steam distilled. That’s just the biomass I have to work with. No choice.