I use hardwood activated carbon from Carbon Chemistry. @Shadownaught can hook you up with both adsorbants. I use a coffee filter cut to lay flat on the Buchner to hold up the bentonite. The key is to make a cake that is thick enough in the center that it reaches and comes up the sides but not so thick that your filter speed drops completely off a cliff. After you get the cake made (which will take several passes of the solvent through the Buchner as you will have a lot of bipass in the initial pour) you can add the carbon on top, again in a slurry. I add enough AC to form an even 1/8 to 1/4 inch layer. I then typically pull the cake dry on vacuum suction for an hour or so so that it really firms up. Prior to putting in your extract you should drop a good amount of ethanol through the cake to hydrate it. You should also flush the cake with about a liter of ethanol after completing filtration.
We do the cake filtration during extraction while the solution is still very cold. It immediately follows our coarse filtration of a Watman paper filter to get out the bulk of the remaining plant matter. There will be a small amount of plant matter left in the solution that will form a layer on top of the AC. You’ll want to occasionally scrape off the very top of the AC to remove the debris and increase filtration speed.
I’ve found I can get 5 or 6 filtrations out of a cake before the color starts to darken as the AC saturates. If you need to do more you can scrape off some spent AC and add fresh AC on top.
Also, your first pour through the carbon will be the clearest. So clear that you might think you just lost all your cannabinoids. Don’t freak out, this is normal. I’ve never seen a significant drop in yield from using AC.
Yeah, I hear ya! Being a production facility my goal was to get rid of the water solubles not fully discover what they are, unfortunately. I often wish I had more room for explorative science in my work. But, the job is to make fine oils so fine oils I will make!
My working hypothesis (best guess) is that my water solubles are predominantly sugars.
At least the ones that drop out once I add MCT.
I have found them to be somewhat sweet to the taste, and “carmellization” seems a very apt discription of what happens to them upon heating.
I’ve posted here somewhere about getting soft caramel through hard candy consistencies in the bottom of a rice cooker (after adding MCT, so I could raise the temp & get rid of the last of my solvent) .
Also got charcoal a couple of times when I got distracted a the wrong time.
We’ve also seen sugars though, again, not since the SOP and filtration improvements. 99% of what we were seeing was something else. They certainly didn’t taste sweet! There were two basic kinds that we observed. Some would cling as an irregular white film on a flask in the rotary evaporator. That was what I assumed was the DNA if only for the fact that it looked similar to dried DNA I extracted in undergrad. In decarb they would coagulate into chunks and gobs or just plaster themselves in a layer of charred sludge on the breaker and thermocouple. I assumed those were the proteins denaturing under heat and precipitating out. At times when I pulled the thermocouple out of the oil it would have a ribbon of black sludge dragging behind it like some kind of terrible cannabis pirate flag. It was all very wrong and often ruined the taste and smell of the oil. We are all very glad to have conquered that particular beast.
It is actually @Akoyeh who is currently battling ppt upon dilution in MCT, and part of the problem is almost certainly that the -80 freezer I was using to extract in died of abuse (unreasonable ambient temps in the lab). So he’s extracting at -35ish
Confiming that his water solubles are sugars seems prudent, but I agree that solving a production problem is way more important when trying to stay afloat in this biz. Yeah, figuring out why it works can be useful later, but if the spice doesn’t flow, then why becomes irrelevant Really quickly.
@Akoyeh Why not use dry ice and a party cooler? Our blast freezer doesn’t arrive for another month. Everything we’ve done so far has been with dry ice and buckets. Tried and true!
@TheLostBiologist we are big fans of bucket Tek! We use it regularly. Dry ice and an oversized styrofoam cooler are part of our current SOP. Doesn’t seem to stop us from extracting some unwanted stuff.
I personally dont like the idea of putting dry ice in direct contact with my product, even if i am doing post processing afterwards. I get my dry ice from praxair, maybe you have a cleaner source for lab use.
The only time the dry ice makes contact with the product is in the bucket. We get our dry ice from a local dry ice supplier. It’s not lab grade, if there even is such a thing.
I think the ethanol reacts with styrofoam? I’d be cautious as to making sure everything in your system is ethanol compatible! Any gaskets, seals, rubbers, etc. along the way needs to not dissolve!
First and foremost, I appreciate the concern. It needs stating repeatedly that
having equipment that is appropriate for the task, and safe for the operator and end user is absolutely mission critical.
As stated, the cooler in question doesn’t hold water.
So no fear of filling it with solvent.
Pretty sure acetone will get you styrene (or at least liquid cooler)
Also pretty sure Everclear in a styrofoam coffee cup won’t do you any more harm than from a mason jar…but I wouldn’t take my word on that.
Both solvent & biomass are stored in nice shiny beer kegs. I’ve described the mods to those kegs around here somewhere. Including the recommendation that you don’t try fitting a 10" tri-clamp ferrule on there.
…because you have to cut the rolled edge of the keg to allow access to the bolts. That compromises the keg, and the ferrule ends up bending over time. making those ethanol resistant PTFE gaskets way harder to get a seal on.
…so I substituted the slightly less impervious viton.
Rather than the ethanol & hydrocarbon susceptible silicone.
transfer hoses are PTFE with stainless overbraid, or whatever elastomer Delta ships with their CUP. (I think I posted my best guess on that too).
@tweedledew I think @Akoyeh is probably using the cooler to chill the biomass not run the extraction. Beyond whether it will survive the ethanol it definitely won’t survive whatever is used for aggitation.
Ethanol has a low (but not negligible) solvency with polystyrene. You will have some chemical reactivity and likely pick that up in traces in your extracts if you have the alcohol in styrofoam at any point. At the low temperatures it’s likely even more benign, but there’s still some reactivity.
