Co2 extraction

sasquatch19

Well-Known Member
What's up everyone? It's been a while, but I'm back here looking for some answers.

I work at a cultivation center in Illinois and we are required to meet or exceed fairly strict standards for our product to make it to the end consumer. Lately, our CO2 extracted oil has been having an issue with meeting those standards.

These are the steps taken to process said oil:

1. Extraction
2. Soak in 99% Lab grade ethyl
3. Filter
4. Winterize
5. Fliter
6. Winterize
7. Filter
8. Rotovap to recover the majority of ethyl
9. Decarb on a hot plate to remove remaining ethyl and decarb material

In process 9, the oil is heated to 116*C which is well about the 78-80*C it takes to boil off the remaining ethyl.

So, first question, How is this possible? If I recall my time in chemistry class, we were taught that your mixture should reach a boiling point of a particular molecule in the mix, and should remain there until all of that compound is boiled away, then the heat should climb until it reaches the boiling point of the next compound in the mixture. If we are heating to 116* there should be NO ethyl left in the mix.

Second question, What can we do to remedy this issue? This has become quite problematic because of the testing rules here in Illinois.
 

jonnynobody

Well-Known Member
What's up everyone? It's been a while, but I'm back here looking for some answers.

I work at a cultivation center in Illinois and we are required to meet or exceed fairly strict standards for our product to make it to the end consumer. Lately, our CO2 extracted oil has been having an issue with meeting those standards.

These are the steps taken to process said oil:

1. Extraction
2. Soak in 99% Lab grade ethyl
3. Filter
4. Winterize
5. Fliter
6. Winterize
7. Filter
8. Rotovap to recover the majority of ethyl
9. Decarb on a hot plate to remove remaining ethyl and decarb material

In process 9, the oil is heated to 116*C which is well about the 78-80*C it takes to boil off the remaining ethyl.

So, first question, How is this possible? If I recall my time in chemistry class, we were taught that your mixture should reach a boiling point of a particular molecule in the mix, and should remain there until all of that compound is boiled away, then the heat should climb until it reaches the boiling point of the next compound in the mixture. If we are heating to 116* there should be NO ethyl left in the mix.

Second question, What can we do to remedy this issue? This has become quite problematic because of the testing rules here in Illinois.
Are you applying heat for the proper duration? I know some BHO producers apply heat under vacuum pressure for 48 hours to remove all of the residual butane. It sounds like you're not applying heat for long enough duration leaving residual ethyl in your product.
 

sasquatch19

Well-Known Member
Are you applying heat for the proper duration? I know some BHO producers apply heat under vacuum pressure for 48 hours to remove all of the residual butane. It sounds like you're not applying heat for long enough duration leaving residual ethyl in your product.

The oil remains on the hotplate at temperature for roughly 8 hours. While on the plate, it is not under vacuum.
 

jonnynobody

Well-Known Member
The oil remains on the hotplate at temperature for roughly 8 hours. While on the plate, it is not under vacuum.
Pull a vacuum on it while heating and double the duration. Should solve your problem. Look up how BHO manufacturer's purge their product under vacuum with heat applied.

I'd vape off most of the ethyl on your hot plate and then toss your final product in one of these for 48 hours. You should have a beautifully pure product.
https://www.toolots.com/vacuum-chamber-stainless-steel-inner-hot-air-circulating-drying-machin.html?cid=1469602950&gclid=Cj0KCQiAjKqABhDLARIsABbJrGmsriBhp_0Qlo5soZdvksr8vRlOtFdHl_zENQejb3Rv0hpUKtv7y2YaAhDzEALw_wcB
 

sasquatch19

Well-Known Member
Update:
We are still having the issue of failing testing for ethyl. As suggested we increased duration on the hotplate to 12 hours and then moved to a vac oven under full vac at 160*F for sometimes up to 10 days. Test results are still coming back with 2000-5000 ppm of ethyl in the mixture.

Any chem majors want to chime in and give me an idea as to why this could be happening? I have readjusted the rotovap and now running the hot water bath at 50*C, the chiller at 0*C, and pulls vac to 93 torrs (123 mbar.)

I'm wondering if maybe the way we add the oil to the ethyl was an issue. Our oil comes out of the extractor at 45*C while our ethyl is about 20-22*C. So I've instructed my peers to not combine them until both are at room temp. Didn't know if it was causing some kind of thermal shock that binds the ethyl to the oil on a molecular level. Our first test with this new method should come back tomorrow (11-5)
 
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