When do you need a centrifuge?

I’m talking to a friend of mine who says that a hydraulic cylinder is going to be fine for our first few pounds of biomass to reclaim our ethanol after cold washing, and after reading that many of you are centrifuging at large scale, it got me wondering, at what point does it become worth it to bother centrifuging up to code?

On that note, would it be possible to just jam our biomass into a decent sized buchner funnel and just rip out the leftover ethanol into a vacuum flask? Is there a reason that people aren’t doing that aside from it not scaling well?


1 Like

Vacuuming ethanol will evaporate more than you’ll recover and would be hard on your pump because of this. You could try positive pressure, like nitrogen, but really that isn’t going to work as well either.

Are you talking about a centrifuge that you fill with solvent or a centrifuge meant purely to pull additional solvent from your material?


the buchner funnel idea is a good one and it is used in chem labs for other things

but you will not get 100% of the ethanol out of the biomass I would think.

it is a good start though.

if using a buchner funnel with low boiling solvents its best to use an aspirator as

your vacuum.

that way you will not hurt the oil in your vacuum pump.

1 Like

Primarily for pulling additional solvent, like a panda that I hear so much about.

@squig I’m okay with less than 100% recovery at this point, at least until I’m at higher scale. Rather than using an aspirator, can I just get away with using a cold trap?

it will help and worst comes to worst and you start to see loss in your vacuum just

change the oil.

Awesome, I’ll give it a shot and see how it turns out. Thanks for your help.

1 Like

I would check the seals and find out what material they are made from too.

just incase ethanol will effect them.

I am pretty ruff on vacuum pumps and they still seem to work.

you can buy seal kits for most good vacuum pumps too if you find that they

have reacted with the small amounts of ethanol your dry ice trap does not catch.

I doubt a H2O Ice trap would be cold enough best use dry ice.

also have a bleed valve just before the vacuum pump.

you will not need to pull full vacuum on the system to get the results your after

and this will decrease the likely hood of ethanol escaping your trap.


We have tried the whole press thang. IMO it’s not as good as centrifugal force. We were using a VERY over engendered “press” from TLS and the amount of solvent that was left in the biomass was atrocious. It was air assisted and some kinda 20 ton press or something still wasnt enough. Panda or screw press will do you a lot better


I think a hydraulic press can be a great first step, following it up with a screw press.


Anyone played with one of these?

Shockingly cheap, can serve as both a soak tank and also initial separation of solids from tincture with auto-dispensing mechanism. Dispense solids into screw press for further recovery. I think this would beat the pants off a centrifuge in cost-effectiveness if it was dialed in. 10000 lb capacity is considered medium-small by their standards.

1 Like

This thread might help with ideas: Bucket Tek (Cold Ethanol Extraction on a Budget)

The issue with pressing is the other junk you squish out. A homemade expeller press is actually pretty effective at removing your solvent, especially for the budget of $1-300 though

True. I think at a certain point though you just need to accept that. I think the whole cryo-centrifuge approach is limited to a very narrow range of production capacities. And people persevere in that approach and end up in a silly situation where their employees are running around filling up 10 centrifuges. Better to use dirty extraction if it’s scalable, as long as the needed post processing is also scalable.


I went through the bucket tek thread, great stuff, and I saw that a lot of people are using pandas and washing machines, and unfortunately the position I’m in is that I’m trying to get licensed so I don’t think they’ll be to code for processing solvents. I think eventually I’ll be in centrifuge territory but for now I could only process 600kg a year anyhow. Thank you for the link regardless.

1 Like

Absolutely agree. I think the cryo fuge method is only one of 100 good ways to skin the cat but is so popular because it’s now a well established method. The larger the scale, the more steps can be afforded to improve cost:output efficiency and like I’ve harped on enough here already, cooling process to -80 is very hard on variable cost

Yes, I have. Very good inline with screw presses in a large-scale etOH extraction system. You must replace the gaskets and seals with material designed for 190 proof etOH; the prefabbed seals of this unit are designed for 20% etOH concentrations and if you run regular extraction contents through… your seals will pop and the bladder of the pneumatic wine press will eventually fail.

@MagisterChemist has been to extractech (long before we were there)

You never saw the wine bladder press? It was he second big oval shapped press in the extraction line up (after the big screw press)

I did, but i never saw it working (it was down for repairs).

1 Like

Not too hard. I found a company that works with jaegermeister for their herb soaks and so it’s already made for high alcohol content.


You must remember, I was also at Extractech long before you were there. Magister had just left when I showed up.

1 Like