What's new
  • Please note members who been with us for more than 10 years have been upgraded to "Veteran" status and will receive exclusive benefits. If you wish to find out more about this or support IcMag and get same benefits, check this thread here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

ethanol extraction and stability

WaterFarmFan

Active member
Veteran
Here is our procedure:

PROCEDURE

In this experiment, the rotary evaporator is being used to distill ethanol out of winterized, filtered butane hash oil (BHO).

1. Add 500 ml of BHO/ethanol mixture to the evaporating flask. Note that greater volumes may be appropriate in situations where a larger flask is used but care should be taken as to avoid filling the flask over half full.

2. Lock the flask into place on the rotary valve and lower the unit into the warming bath.

3. Set the temperature of the bath to 25ºC.

4. Set the rotation of the flask at 160 rpm. Note that faster speeds may be achievable in a larger flask but operators noticed that higher rotational speeds in the 1 L flask resulted in excessive bumping.

5. Set the initial vacuum level to 80 mbar to begin the process. Increase the vacuum over the course of the distillation as follows.

a. 0-1 min: Pull down for atmospheric pressure to 80 mbar.

b. 1-5 min: Hold at 80 mbar.

c. 5-10 min: Reduce pressure to 60 mbar, hold. At 10 min, about 50 ml of ethanol should have been reclaimed.

d. 10-15 min: Reduce pressure 40 mbar, hold. At 15 min, about 100 ml of ethanol should have been reclaimed.

e. 15-45 min. Reduce pressure to 20 mbar, hold. Vacuum does not exceed 20 mbar but will remain on constantly at this point. At 45 min, about 450 ml of ethanol should have been reclaimed. Note that it is important to leave some ethanol behind so as to be able to easily remove the remaining material from the evaporation flask.

f. The material is collected, spread on PTFE sheets, and placed in the vacuum oven to complete final purge.

RESULTS

Once a pressure of 20 mbar has been achieved, ethanol is recovered at a rate of 11.6 ml/min. This can vary slightly due to the density of the product ie. Ratio of BHO to ethanol. Faster distillation rates are achievable at higher temperatures but more supervision is required to minimize bumping. Furthermore, qualitative evaluations suggest that higher operational temperatures resulted in a somewhat degraded final product. Cold temperature distillations are possible as well but result in increased distillation time and no noticeable improvement in final product.

The unit is easy to clean and dismantle but it can be difficult to remove all of the material once distillation is complete. This is an issue that all rotary evaporators have however and it should not be held against this piece of equipment in particular. As a result, it is up to the operator to make sure that the consistency of the final product is appropriate for their final purpose.

Manually refilling the collection task is easy but somewhat time consuming as the operator has to take care to bring the vacuum down slowly when starting a new batch. Continuous operation is possible with additional equipment and is most likely the missing piece in terms of integrating this equipment into a production setting.

What are your thoughts on lower vacuum levels as it pertains to the bulk removal of ethanol? Does it provide more stability (equilibrium?) within the apparatus or just lower the boiling point even further? I ask because I typically use a cheap HVAC vacuum pump instead of my Varian with the following setup:

2L heating/stirring mantle -> 2L 24/40 2-neck boiling flask (-> all glass thermowell) -> 200mm vigreux column -> 3-way 75 degree head (-> glass stopper) -> 200mm Dimroth condenser -> Friedrichs condenser -> Straight vacuum take-off adapter (-> cold trap -> vacuum pump) -> 2L boiling flask (in insulated sleeve with dry ice)

When I keep the boiling flask filled between 50-25% (and monitor heat and stir settings), I am able to achieve .8L-1L per hour removal with thermocouple readings in the 50F-60F range.
 

Gray Wolf

A Posse ad Esse. From Possibility to realization.
Mentor
ICMag Donor
Veteran
What are your thoughts on lower vacuum levels as it pertains to the bulk removal of ethanol? Does it provide more stability (equilibrium?) within the apparatus or just lower the boiling point even further? I ask because I typically use a cheap HVAC vacuum pump instead of my Varian with the following setup:

2L heating/stirring mantle -> 2L 24/40 2-neck boiling flask (-> all glass thermowell) -> 200mm vigreux column -> 3-way 75 degree head (-> glass stopper) -> 200mm Dimroth condenser -> Friedrichs condenser -> Straight vacuum take-off adapter (-> cold trap -> vacuum pump) -> 2L boiling flask (in insulated sleeve with dry ice)

When I keep the boiling flask filled between 50-25% (and monitor heat and stir settings), I am able to achieve .8L-1L per hour removal with thermocouple readings in the 50F-60F range.


Lower vacuum and less heat decarboxylates less. Too low a vacuum and you get "bumping".
 

WaterFarmFan

Active member
Veteran
Lower vacuum and less heat decarboxylates less. Too low a vacuum and you get "bumping".

Makes sense. I assume bumping in rotovap parlance means solution getting past trap and into condensers? I use the vigreux column in my setup to act as the buffer in this regard.
 

Gray Wolf

A Posse ad Esse. From Possibility to realization.
Mentor
ICMag Donor
Veteran
Makes sense. I assume bumping in rotovap parlance means solution getting past trap and into condensers? I use the vigreux column in my setup to act as the buffer in this regard.
Bumping is a sudden explosive release of bubbles.
 

AK Extracts

New member
How are you doing this, with molecular sieve? Does it removes terpenes and other organics as well as the water? Would love some more details. Thanks.

Exactly, we use molecular sieves (basically reusable pellets available on the internet. We use a hydrometer to check and make sure that 200 proof ethanol is obtained.

I don't believe that the molecular sieve would remove terpenes, but given their high boiling point and the relatively low temps that you'd use, there shouldn't be any making it into the alcohol collection vessel anyway. As far as other organics, I don't believe we are extracting very many (cold ethanol extraction) and what we do extract would be left behind in the oil and not volatize and recover to the collection vessel. We haven't had any issues getting 200 proof, I would recommend not leaving the ethanol on the sieve too long (i.e. check it everyday).
 

AK Extracts

New member
Bumping is a sudden explosive release of bubbles.

Interesting. We often run the vacuum right on the edge of that, meaning that we lower the vacuum until we get a low boil. Sometimes, because that line is pretty fine, we'll get a brief but vigorous release of bubbles.

What I'm hearing is that debarbing the oil, even a little bit prevents stable shatter. In general our oil tests around 1-2% THC and 70-80% THCA, meaning very little decarbing is happening. Still, it sounds like our ethanol recovery parameters of -750mb and 38C, especially the 38C, might be the source of our sappy crystallized honey texture.
Thanks
 

WaterFarmFan

Active member
Veteran
Exactly, we use molecular sieves (basically reusable pellets available on the internet. We use a hydrometer to check and make sure that 200 proof ethanol is obtained.

I don't believe that the molecular sieve would remove terpenes, but given their high boiling point and the relatively low temps that you'd use, there shouldn't be any making it into the alcohol collection vessel anyway. As far as other organics, I don't believe we are extracting very many (cold ethanol extraction) and what we do extract would be left behind in the oil and not volatize and recover to the collection vessel. We haven't had any issues getting 200 proof, I would recommend not leaving the ethanol on the sieve too long (i.e. check it everyday).

Great stuff! Which brand of pellets are you using? Terpenes fascinate me... They are so volatile, that I don't think (some) play by the simple boiling point rules. Many will evaporate rather quickly at room temperature if left out. My observations of smelling my vacuum distilled ethanol is that it definitely retains some of essence if you use high quality material to extract with. I love to make extract with flowers that I know well, as it lets me compare the efficacy in different states.

Back to your process. Have you tested the end product with your reclaimed and sieved 200 ethanol versus stock 190 (Everclear)? This might provide a baseline. Again, I don't have a rotovap, but use an efficient vacuum reclaim solution. Thanks!

WFF
 

AK Extracts

New member
Great stuff! Which brand of pellets are you using? Terpenes fascinate me... They are so volatile, that I don't think (some) play by the simple boiling point rules. Many will evaporate rather quickly at room temperature if left out. My observations of smelling my vacuum distilled ethanol is that it definitely retains some of essence if you use high quality material to extract with. I love to make extract with flowers that I know well, as it lets me compare the efficacy in different states.

Back to your process. Have you tested the end product with your reclaimed and sieved 200 ethanol versus stock 190 (Everclear)? This might provide a baseline. Again, I don't have a rotovap, but use an efficient vacuum reclaim solution. Thanks!

WFF

I agree, you're absolutely right that some (all?) terpenes don't play by the BP rules, otherwise you wouldn't be able to smell marijuana unless it was heated, right? I definitely think you lose terpenes anytime you expose marijuana to heat or even time. That said, as long as the input material is aromatic and flavorful we've never had an issue with "bland" oil. I sometimes feel that people will do anything and everything to retain terps that were never there in the first place and there are diminishing returns on effort.
We test our ethanol with a hydrometer to make sure it's 200 proof. We start with 200 proof ethanol as opposed to Everclear to begin with, so that helps. Water is the enemy obviously so the less you start with and the more you can render immobile (cold, limited contact time, etc.) the better.
I don't think the molecular sieve brand matters a whole lot as long as it's lab grade. We bought ours on Amazon and it's about $20/lb. The thing to watch for is coloring, which you don't want. Our first batch was reddish and colored the ethanol red if left too long. You want grey or white.
 

WaterFarmFan

Active member
Veteran
I agree, you're absolutely right that some (all?) terpenes don't play by the BP rules, otherwise you wouldn't be able to smell marijuana unless it was heated, right? I definitely think you lose terpenes anytime you expose marijuana to heat or even time. That said, as long as the input material is aromatic and flavorful we've never had an issue with "bland" oil. I sometimes feel that people will do anything and everything to retain terps that were never there in the first place and there are diminishing returns on effort.
We test our ethanol with a hydrometer to make sure it's 200 proof. We start with 200 proof ethanol as opposed to Everclear to begin with, so that helps. Water is the enemy obviously so the less you start with and the more you can render immobile (cold, limited contact time, etc.) the better.
I don't think the molecular sieve brand matters a whole lot as long as it's lab grade. We bought ours on Amazon and it's about $20/lb. The thing to watch for is coloring, which you don't want. Our first batch was reddish and colored the ethanol red if left too long. You want grey or white.

Nice info. I am mixed on using 200 vs 190 proof. I went through 5 gallons of Extractahol 200 proof, and honestly I could not tell a difference between that, fresh 190 or re-using my vacuum reclaimed etoh in the quality of the extract, as long as keep my temps very cold. If I never let the soaked or filtering material get above -30C at anytime, it is aces all around. If I can keep the material colder than -40C throughout, I get even better (less) color from same material, but never a single hint of green below -30C.
 

Cannabologist

Active member
Veteran
The colder the ethanol the more shattery.

Warmer ethanol will make it more tacky and like super glue if it is room temp.

Costs and benefits........



Warmer ethanol picks up more terps and is a much tastier product, but can bring more chlorophyll and so you would want to do a quicker wash.


Colder/cold is again more shattery to shatter but doesn't pick up as much flavor as warm, and will pick up less chlorophyll but still some if you go to long. Its more of that hash taste. Its still there but less.

I like the tacky shit of course cause I want to taste my girls but mm that sticky...





I use room temp material I don't bother to freeze it.
 

WaterFarmFan

Active member
Veteran
The colder the ethanol the more shattery.

Warmer ethanol will make it more tacky and like super glue if it is room temp.

Costs and benefits........

Warmer ethanol picks up more terps and is a much tastier product, but can bring more chlorophyll and so you would want to do a quicker wash.

Colder/cold is again more shattery to shatter but doesn't pick up as much flavor as warm, and will pick up less chlorophyll but still some if you go to long. Its more of that hash taste. Its still there but less.

I like the tacky shit of course cause I want to taste my girls but mm that sticky...

I use room temp material I don't bother to freeze it.

Great to hear how others are doing ethanol extraction. Do you dab most of your finished product? Also, how dry is your material before doing room temp extract?
 

Cannabologist

Active member
Veteran
^ Dab it, roll it, put it right on weed in a bowl mostly though cause I smoke bowls.


Its dry normal herb, ie. flower or shake. Obv shake needs a quicker wash but I like a quick wash anyway its always cleaner and then you can rewash the material or hit it with hot water and evap that and use all the residual oils and stuff for edibles. Its a simple quick wash ethanol double (triple?) coffee filtered pretty ghetto style modified from techniques on here and heard elsewhere...


.. Like a method where they take a whole fresh chopped live plants and dunk it in a 5 gal bucket of ethanol ie. everclear and then evap that.

My evap is ghetto also but I get all that shit out its pretty easy on a hotplate and ethanol evaps easy and clean and residual would burn off anyway. I have also taken the 1st wash rechill for 12-48+hrs and filter again from the freezer.


I've done a bunch of ghetto chemistry like this> what temps, what times, what results.. I didn't like freezing material I know Ive tried it, the material is all, idk it causes too much chlorophyll pickup also the material picks up water in the freezer and it makes the extract fucky I wouldn't recommend it you want regular material not over dry or frozen... You Can use fresh though hell yeah........ BUT its the same in my opinion as regular dried material there is no better benefit to doing it from a living plant thus "live resin" PPFT lol k.. K boys k.. More marketing for the saturated market to make another class beyond top shelf and super call and super duper call and super duper duper call and super top shell and super duper duper uper like wtf how far can this go? Now they call some bs DIAMONDS.... Have you heard this???

Its fucking weed kids. Back in the days they called it dope. Now dope is heroin. I guess they were always both. lol.


You can whip it, you can bake it, you can shake it, you can candlestick make it. But its still fuckin pot!
 

hash head

Member
Now they call some bs DIAMONDS.... Have you heard this???

Its fucking weed kids. Back in the days they called it dope. Now dope is heroin. I guess they were always both. lol.


You can whip it, you can bake it, you can shake it, you can candlestick make it. But its still fuckin pot!

says the guy making qwet... have you ever had good sauce or diamonds?? why the hate.. you just sound like an angry fuck.. dope is short for dopamine.. which technically cocaine interacts with the most.. who cares what they called it back in the day? Hash keeps evolving and people who spew this "back in the day" bullshit aren't enjoying the evolution how they could and should.
 
Top