I’ve been thinking about a cheap and quick way to pre chill a packed material column before extracting with hydrocarbons. I have been cooling the solvent to the desired temperature, but the temperature of the steel column and plant material inside seem to be stealing a lot of the heat energy as the thermocouple on the bottom of the material column never gets to the temperature of the solvent when injected.
Freezers are nice but take a long time to get the column fully frozen and can be expensive up front (with power costs). LCO2 and dry ice are good but still take time and are pretty wasteful. I am considering injecting LN2 thru a packed material column just before starting a run. Basically get everything set up and vacuumed down, then inject LN2 thru the top of material column and simultaneously vent out the bottom before vacuuming down again and starting the run.
Has anyone tried it or have any thoughts?