We recently added a chiller to our bho extraction setup. For the first few runs at -80 and we realized our yields had dropped, but figured it was because of no more fats and lipids in the yields. But the run last night really threw us off, we practically got no yield, say less than 1%, there was heavy green color extracted in the butane but no trace of oil. We tried different solvent to trim ratios 5:1 to 9:1(we normally run 4:1- 6:1 ratio), still nothing. We turned the chiller down to -20 and ran the socks and we got close to10% yield again. Why did it not yield anything at -80? Has anyone ever encountered this issue before?
We are using 70/30 butane/propane mix. I can give more details if required to help with this issue. It’ll be interesting to see what the issue turns out to be. Also, we bypassed the crc to rule it out and still no yield.
I think the quick answer would be that as the temperature goes down so does the solubility. -80°C is definitely too cold for extractions.
did someone sell you material that was already extracted?
Do you have any analytics, if not on the latest run, from your previous methods? Is the trim fresh or dry?
I turned down the chiller to -20 and ran the same marerial abd it yielded fine.
Dry trim, fairly fresh indoor material, i got around 10% yield when i turned the chiller down to -20 so its not the trim.
We fill 10 lb socks, soak for 10 mins with 25 lbs, then run 25 lbs through the column, so 5:1 ratio.
Inknow plenty guys running at -60 to -80 and they dont seem to have this issue. Also, we used to run co2 through a system few years ago, the temp stayed well between -50 to -80, never had an issue.
It’ll be interesting to see what the issye turns out to bo
A note - just because the chiller reads -60, doesn’t mean the solvent is -60.
Consider a precision x10 - tiny lil solvent tank, at best running around 3-4:1 if running both columns simultaneously at 2kgish per column. Solvent tank is hooked to a unistat 815 set to -60, primary condenser runs off a -20 huber. That solvent that’s being recovered back into the solvent tank isn’t -60, nor is it -20 though it’s likely not far off by that point, and since its a precision x10, you used the whole solvent tank for both columns. How long do you think it’s going to take a non-agitated solvent tank (because who does that) from -20 to -60? Probably longer than your tech is giving it before the next run is started, right? Unistats are exceptionally precise chillers, but really struggle with large temp deltas due to, in part, their small reservoirs.
There’s a lot of very strong opinions about temps for hydrocarbon extraction, but as long as you provide yourself with process data necessary to make an informed opinion (temp probes in contact with liquid solvent), you should be able to figure most problems out with just a pinch of critical thinking.
Running your BHO extraction at -80°C likely caused drastically reduced yields because hydrocarbon solvents like your 70/30 butane/propane mix have significantly reduced solubility for cannabinoids at ultra-low temperatures. At this temp, the solvent may pull unwanted compounds like chlorophyll (explaining the green tint) but fail to extract oils, leading to yields under 1%. When you raised the temp to -20°C, yields returned to normal (~10%), confirming solubility was the issue. Ideal extraction temps are typically around -40°C to -50°C, or just cold enough to avoid fats and waxes but still effective at dissolving cannabinoids. If you know plenty of guys running at -60 to -80, maybe reaching out to them might be a good idea?
Best of luck!
What you are saying makes sense, its definately something to do with the temp i was boasting that i jnow plenty of guys doing -60 or more(and plenty of guys probably a exaggeration, i know a few). I was saying that in a way that I wonder how they’re doing it. But then i thought about it theyvrun FF 90% of the time
I dont have a unistat, the reservoir is big enough on the chiller(specs say -80 at 14kw, and i get that could be off and i will be getting a manual reading on the solvent roday) but i get what you are saying. I do have a -20 chiller on the heat exchanger and then -80 chiller on the solvent tanks and material columns, and if then chiller is not running at -80, possibly at lower temps, what are you suggesting what the issue might be? Right now the data and suggestions so far are saying the solvents might not be soluble at that temp.
We will be trying some different runs with the chiller set between -30 to -50
What’s the pressure in your material column when soaking and then when pushing into recovery tank?
That must be a big chiller, dont know what system you are running, but sounds like a lot of load for one chiller on solvent tank and material columns. Cool thing about chillers is we can easily change the temp(unlike dry ice) just drop it to -60(thats my sweet spot). Sometimes colder isnt better, requires longer soak times and longer soak times tend to attract undesirables(chlorophyll) and yes, running warmer may seem to increase your yields, but like you said “fats and lipids” that may require some extra post processing (unless ofcourse you are making shatter or crumbles). Just run your system keeping in mind whats most important to you, time or yields. Would ve good to know what type of media you are using fir the crc column. I recommend zeo clear y. Good luck man!
Im running 6 - 6x48" columns(jacketed and chilled to -80) 2 surge tanks(300 lbs each jacketed and vac’d, not chilled) 10x24" crc, typically use W3, silica and alumina with beads on top) 2 - 50 lb recovery vessels , 1 - 6×48" heat exchanger double jacketed, chilled to -20 and vac’d) and 2 - 400 lbs solvent tanks(chilled to -80)
Temps at chiller outlet(into the injection columns show at -80(actual could be different, i need to install a temp sensor on the actual columns) and the temp at inlet chiller fluctuates between -50 to -70(again, the actual could be different) coming out from the solvent tank, into the chiller.
And yes, we are planning on doing some test runs at -30, -40, -50 and -60. So far it seems like the solvents are getting too cold and that should solve the issue. Thank you
We push it between 40-60 psi and burp them between 80-100psi
-80c is to low for 70/30 solvent and jacketed material columns. Try -40c and go from there, or valve off the cooling fluid to the mat column jackets and let the -80c solvent warm up some during pressurized soak.
When at -60c to -80c I’ve had to soak the material 20-40 minutes minimum, running 99.9 butane. Never had any issue pulling chlorophyll at those temps unless you’re dealing with material that was machine wet trimmed or fresh frozen that has previously thawed and was then refrozen.
kick the propane use only n tane. Propane looses solubility as it gets colder run pure n tane yields will grow
-20 to -40
And diminish again when you go lower than -60c. Even -60c is pushing it if you’re trying to minimize loss of yield. 