Cake method Solvent recovery/handling

[Shattered_Symmetry]

Hi Everyone,

A friend of mine recently discovered the cake method and was wondering what would be appropriate apparatus for containing and recovering the solvent during extraction along with some other questions.

1. He wanted to know if denatured alcohol with the constituents listed below might be an appropriate solvent. His intention is to minimise the use of toxic substances such as Methanol and isopropyl, does anyone know anyone who has tried/can see any problems with using it?

Ethyl alcohol <92%
Methyl alcohol <4%
Ethyl Acetate <4%
Methyl isobutyl ketone <1%
Heptane <1

2. To minimise exposure to fumes and reduce the risk of fire he wanted to use the correct distillation apparatus to recover the solvent during evaporation. He was hoping to find an appropriate alternative to a round bottom boiling flask as removal of the cake from this vessel may be difficult. Could anyone suggest how this might be overcome?

3. He was also planning on the construction of a fume hood/cupboard to remove any harmful vapours during the process. Does anyone have any pointers on how he might do this? one concern he has is that the electric motors in typical desk/pc fans may ignite the fumes and was wondering if this is the case.

Great to be on the forum guys and thanks very much for reading!

 

[Dr_Sister]

FYI - methyl alcohol = methanol

If you are worried about your cake getting stuck in a rb flask, empty it out onto an evaporation tray when the distillation is almost finished and let the last of the solvent evaporate

 

[Garfield]

3. He was also planning on the construction of a fume hood/cupboard to remove any harmful vapours during the process. Does anyone have any pointers on how he might do this? one concern he has is that the electric motors in typical desk/pc fans may ignite the fumes and was wondering if this is the case.

No problem here if you use axial fans (pc fan), because they operate sparkfree, so you don´t have to worry about igniting fumes.