Falling film evaporator is very fast at recovering ethanol after extractions, however, there are a lot of details I can’t seem to find an answer for.
DeltaSeparations claims to recover up to 90% solvent. What happens to the rest 10%? Does it evaporate through an outlet in the pump, or does it remain in the crude extract?
I know that for ethanol extractions we acquire water from cannabis, which is not desired. Can FFE evaporate only ethanol (at best 95% pure ethanol), or will all the collected water from cannabis result in recovered solvent?
And lastly, (assuming no solvent remains in crude after FFE) how do we remove the oil from FFE without breaking vacuum?
The last 10% stays in the crude, since that model (as are most others) is a single stage evaporator. If you take 100% out, moving the crude gets extremely difficult. Most guys finish in a roto or in their decarb reactor. Big boys finish in a second FFE or use a multi staged one.
Water forms an azsotrope with the ethanol, eventually watering down that ethanol so much it starts pulling excessive chlorophyll and need sto be reproofed or replaced
I wonder if that’s a factor of cannabinoid solubility or if it’s more of a solvent saturation issue (the chlorophyll is taking up space that otherwise would have been filled with cannabinoids)?
The membrane company im working with has figured out a way to improve RO filtration to efficiencies above 95% from 42% using membrane distillation
Pretty much you take the waste stream from RO and do something called membrane distillation which is where you distill the water through a special hydrophilic membrane that won’t let anything else through.
We use to just throw the waste stream of RO away because it’s so dirty, this allows us to save that precious water and utilize it while using solar energy to do it (yes, that’s right SOLAR)
If you’re freezing biomass before extraction and keeping ethanol sufficiently cold before & during extraction you’ll pull considerably less water than extraction at room temps. Over time doing room temp extraction with reused ethanol will result in lower proof as it continues to pull water from the biomass and ambient moisture in the air.
The amount of ethanol left over in the output crude after the FFE is dependent on a bunch of factors, not the least of which are design of the FFE, vac level, ethanol mix injection temperature & atomization, FFE hot side loop & process temp and cold side loop & process temp. Within reason we usually adjust the hot side loop temp and vac level to achieve a desired output viscosity, as Future said moving pure crude is a pain in the ass, as well there isn’t an FFE on the market I’m aware of that has sufficient residence time with heat to fully decarb your crude in a single pass, without the decarb step it makes distillation a real headache.