Winterisation/Freeze-precipitation conundrum

Dear all,

I would like to ask you guys some technical questions on winterizations as I feel I am not finding the appropriate information in the scientific literature or on the internet in general… in particular the limit of /maximum lipid/wax content inside of the crude oil that will not affect the distillation.

I am in the process of setting up a cannabis processing facility to perform cold-ethanol extractions to produce full-spectrum extracts and distillates. I have experience with a smaller scale operation using “bucket teks”, rotovaps, manual winterisation, buchner funnel and SPD, but now I am planning an to operate a larger setup with a less “hands-on” method, which is why I need clarity on how to design the setup/workflow.

The gist of the process is:

Extraction:

  • 100L EtOH storage tank with chiller
  • cold ethanol extraction inside a centrifuge unit (7.5 kg biomass capacity)
  • 100L buffer tank
  • two-stage tubular membrane filtration unit
  • 100L holding tank
  • Falling Film Evaporator

Devolatilisation/Decarboxylation:

  • Reactor vessel (Devolatilisation & Decarb)
  • Rotovap (Concentration)
  • Vacuum Oven (Purging for Full-spectrum Extract)

Distillation:

  • Wiped Film Molecular distillation

I have been wondering about the specifics regarding the freeze-precipitation/winterization.
I understand that the particle size of the biomass, the EtOH ratio (to biomass), the contact time (EtOH between biomass) and the temperature of the EtOH are factors that influence the amounts of wax/lipids that are extracted from the plant material.

I am planning to extract the biomass using EtOH at -40C in a 1:5 ratio (biomass:EtOH) (what would be an appropriate time per extraction run and how many times is it advisable to repeat this step to maximise the extraction efficiency?).
Will these parameters require me to perform an additional winterisation step as part of the downstream processing prior to distillation? I have come across information that if the EtOH is cold enough during extraction, one will not need to perform an additional winterisation step. Is it crucial to perform a winterisation step regardless? Would one perform the winterisation prior or after decarboxylation?

Sorry for the long message, I hope this serves as a sufficient starting point for a discussion on this topic.

Kind regards,

DHAN

Search bar is your friend.

If you have the capacity to retain your solution at -40C even with losses to the environment, 20-30 minutes is usually enough with fresh solvent.

In terms of winterization—if you’re using -40C ethanol the amount of lipids extracted are negligible. You won’t need a winterization step, more than likely.

The standard solvent biomass ratio is 1gallon per lb, convert units as needed. 5:1 might be right when representing kg:kg ratio…I’m not sure I’d have to do the math.

Peer reviewed info from edible oil industries will only get you so far. You need to spend a lot of time searching to find some answers. That search bar is the ebscohost of cannabis extraction

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A -40 extraction shouldn’t pick up enough wax to bother winterizing in my experience. An extraction run shouldn’t take more than 20 minutes conventionally, and in actual fact there are techniques for getting it done in 10 minutes.

Is this all equipment you’ve bought so far, or just equipment you’re planning to buy?

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Thank you for your insight.

this is the equipment that I’m planning to buy. I’m currently busy with the workflow diagram/process flowchart and populating it with the technical details of the equipment. The need for a step winterization has a big question mark attached to it (and where to add it if required).

Thank you for your insight.

this is the equipment that I’m planning to buy. I’m currently busy with the workflow diagram/process flowchart and populating it with the technical details of the equipment. The need for a step winterization has a big question mark attached to it (and where to add it if required).

Thank you, yes I’ve found the info that I have been looking for. This forum is a treasure trove.

I couldn’t find numbers on the actual concentrations of wax, but I suppose that is going overboard.

https://lipidlibrary.aocs.org/

https://lipidlibrary.aocs.org/edible-oil-processing

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Thank you, this looks very comprehensive. I suppose one can work backwards, i.e. “instead of how do i remove lipids?” to “how do i isolate them?”

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