Trichgnomes
Member
Good point! I am defining a single pass system as a column with a ~1/8" injection port on one end and a filter clamped to the other. My best yield repacking and with two runs was 21.6% and 100% of the butane is lost. Yield has varied considerable by strain.
I too used 1 1/2" tubing for my first ball valve controlled "soak" system, and use 1 1/2" Schedule 10 304SS for our butane extraction and recovery system that can flood, soak, or pump the butane through the material.
Butane recovery is about 100% , but best yield to date was 22.2% using a 30 minute flood, and soak cycle, where I flood with one volume of new butane every time the system pressure is pumped below -10" Hg. With the current system that is about ten to a dozen times and column volumes in 30 minutes.
Wow, impressive speed on that system.
The one that I used did not utilize any pumps, just temperature differentials to create a vacuum. The butane passed through all of the plant material in under a minute, but the recovery took painfully long (4+ hours).
I could have recovered 100% of the butane, but chose to use the remaining 15% (+/- 100ml) to pour out of the extractor into a pie plate, and evap off remaining solvent in same manner as open air extraction.
I'm still not really sold on absolutes, and find the most flavorful extracts to be a primary wash with non-polar solvent and evaporation of chosen solvent (butane).
Every experiment thus far I have had to sacrifice terpenes to remove ethanol entirely. While the product does seem to bee more consistent 'shatter,' and retains form for much longer, it is still not my preference. Have yet to try a vacuum removal of ethanol however, which I still remain optimistic for.