BHO Cryo System?

I'm considering making a BHO system. To recycle the butane normally a coolant recovery pump is used. It's quite expensive and not actually designed for the job. I don't want to spend the money on something that can contaminate my product, and I'm not needing to make an obscene amount, so max speed isn't required._

After looking at BHO and supercritical CO2 I think I have a pretty good idea for a simple extraction system.

Parts:
2x New Propane Tank (stainless would be really nice, but can't find)
1x Dryer Canister
1x Material Canister
Hoses
Dry Ice
Insulated box/cooler made to fit 1 propane tank with room for dry ice.


Full tank (room temp) -> hose -> Material Canister -> hose -> Empty tank in cooler with dry ice

Effectively this is a cryo-pump based system. The -109F temps in the cooler will cause the butane to condense back into liquid, almost all of the butane will be in the cooler tank within a few hours.

Any reason this won't work? What do you think? I'm curious how you would remove the extract and if a 3rd tank/chamber would be required.

It's liquid at -1 C right? That's just below freezing. If you're in the northern hemisphere you might be able to just go outdoors on a cold day or in an unheated garage to do it.

Depends on what exactly is in it.
n-butane is -1c/30f
isobutane is -12c/11f
Propane is -42c/-44f

All three of these are commonly in "butane" used for extraction.

You also need to both condense and evaporate at the same time for this to work. So unless you want to run a hose from indoors to outdoors and use the heat of inside vs the cold of outside, I would prefer to go buy $5 in dry ice.