Has anyone here ever tried tangential flow filtration (TFF) on cannabis extracts? I used it for concentration and/or buffer exchanging of DNA/virus previously. It’s simple enough and since you’re using cannabinoids (i.e. not one time use for sterile operations) you’d likely be able to regenerate the membrane. I have a picture of the largest TFF I’ve ever used for reference. Problem is cannabinoids are tiny. They would likely fall through even the smallest membrane. The membranes are alcohol, detergent, water, and salt stable. I know we used mild organics on them but never in high concentrations.
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Hello NewLevelProcess, YES! we do, the device your showing here is typically used, as you point out, in the Pharma industry (which we are also involved with). For this industry there is a membrane (that we are building into a system) that has been designed for this purpose and is compatible with the solvents and temperatures. It has two membranes on board and together they act to reduce process steps in an automated process way. Would love to work with you! Thanks, Greg, gregh@heyesfilters.com
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I’ve talked with them extensively and it doesn’t seem like they have a good enough handle on cannabis chemistry. Plus their membranes have to be backwashed after every few runs costing you a ton of time. They’re also prohibitively expensive. We are working with Heyes filters to develop a cost-effective disposable filter cartridge that doesn’t take time to backwash.
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Well, in terms of washing that hasn’t really been my experience with them. I’ve also met their engineers in person and while i think you used to be right about experience they have been working overtime to familiarize themselves and are flying all over to do r&d with people in the last year.
One thing you’re right about though is they are very pricy membranes! If you can find other ones that hit those tight sizes then by all means I’ll buy them.
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yup, and we should start to see the true lifetime of these membranes since some have been in operation for about a yr by now. We need to be able to identify and be testing for any product contamination originating from a degrading membrane as well.
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Hello, we have a nano filtration unit with 500da and 900da evonik DURANEM membrane. From the first tests we see that a lot of CBDa is excluded even though the molecular weight is smaller than the membrane itself. I have tried multiple tests with pressure/temperature/flow…with no success. Do you think that decarboxylation would help ? any other inputs would be more than welcome ! MAny thanks, T
Thomas - That is pretty typical actually… Understand that membranes usually work on charge repulsion. In a non-aqueous solution, with neutral molecules, they work only on size exclusion. In an ethanol solution, particularly ethanol with water, the charge repulsion will result in higher rejection of ions. With nanofiltration membranes, the charge and strength of charge is also pH dependent AND functional groups and charges can result in some changes in performance as steric hindrances develop… I really need to finish that primer some time soon… Decarbing will address the charge repulsion issues to a great degree… but do you really WANT to decarb. The cut-off listed is also not absolute, but rather representative of a size distribution. Trial and error of lots of membranes is often the best approach.
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The cutoff sizes are also not only dependent on the solute but also the solvent and the pressure. The duramem cutoff sizes are sized according to their performance in acetone, and in alcohols actually are somewhat reduced. Their current dewaxing suggestion is puramem s600, and i can verify it works pretty well
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Thank you @ProcessMan ! Today I had “better” results with a de-gummed extract., d0n’t know if gums may interfere ? I have also find out that a higher temperature (40°C) make a better permeate flow than lower temps . I am going step by step. I will try to find more information on the tracks you gave me in your message. I have another question though. Do you think that a new membrane needs a bit of time before giving the best results ? again thank you, T
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Interesting. Evonik told me PURANEM was better with non polar solvent and they pushed me to buy the 500 and 900 dalton What pressure & temperature are you applying to make it work “pretty well” if I may ask?
When was it that they told you that? I used 20C, 800 psi
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I will call them tomorrow and check the S600 for availability. Thanks a million for the tip. T
Another question if you don’t mind. What is the dilution of your ethanol/extract mix? We use 1:10 (like winterization)…I am pretty sure I should concentrate a bit more ?! 800 psi is some serious pressure ! We cannot exceed 290psi with the DURANEM.
You know that’s probably one reason they recommended s600 to me. The pressure rating on it is 3x higher.
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Great feedback @MagisterChemist… I will finally get around to sending out that primer I promised. If the cross-flow is too low, or there is too little solvent, one will see increased passage across the membrane. Let me put together a couple pages on mass transport to help explain why. There is a practical limit when you switch from the membrane to a thermal process… usually once the cannabinoid gets so concentrated that it starts concentrating at the membrane surface. This is undesirable.
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Can anyone post a pic of the filter skid/filter set up?
Lol
It’s a cross flow filtration system.
If you cant even figure out what it is please dont blow yourself up attempting to build one.
These skids generally operate at above 600 psi, with solvent in there that can create a bomb
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No need to be tough. I have spoken with sterlitech about the puramem skid systems. I’m aware of how the nano filtration works. Here is the diagram for the 1812. I was just asking to see if anyone had a pic of a working system. I’m curious as well as others I’m sure
1812_Manual_Interactive.pdf (506.4 KB)
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You can find pics on their website if you try…
I have and they are fine. I was just hoping to see a community members set up.