So, i’m a n00b to CLS and i would like to recover Whip it Premium Butane into my 30# tank. I did the math and wanted to make sure i was correct before i go doing anything…
The MSDS sheet says Whip It has a relative density (i’m assuming this is the specific gravity?) of .559. also according to it’s MSDS It’s make up is 54% N tane, 24% iso, and 22% propane.
SO: 30# / .0361 = 831
831 x .8 = 665in3
specific gravity of whip it .559 x .0361 = 0.0201799
665in3 x .0201799 = 13.4196335lbs of whip it in a 30# tank, Correct?
hopefully this post doesn’t annoy you. Just trying to be safe over here.
edit: the reason i would like to use whip it is due to its ability to move at a lower temperature than the pure Ntane i can source locally and i can’t seem to find a mix very close to me.
Just for jollies, I compared Whip it’s MSDS .559 stated density to my calculated density and discovered a disparity if it is indeed 54% n-Butane, 24% Isobutane, and 22% Propane. Not enough to significantly affect your calculations, but with the new specific gravity figures, here are the calcs:
(.54 X .601) + (.24 X .563) + (.22 X .495) = 0.32454 + 0.13512 + 0.1089 = 0.56856 specific gravity
Because we extract with refrigerants.
Here’s a follow up for the big brains.
How much vapor do you need to let loose to “auto refrigerate” down to the boiling point of your solvent. Propane to -44f. Butane to 0f. Let’s assume 100lb tank insulated tank. And a starting temp of 70f.
Follow up question. Once we hit 0psi, if we begin pulling on the vapors with a trs21 what is lowest temp practically achievable for each solvent.
Also what changes if instead of venting then pumping to atmosphere, we vent then pump into a holding tank for later recovery.
Edit @Graywolf ?
A 100# tank is its rating for water, and it can only be 80% filled for LPG.
Butane has a specific gravity of .601 and Propane is .495 so it would hold 100# X .80 X .601 = 48 lbs of Butane and 100# X .80 X .495 = 39.6 lbs of Propane.
70F – 30F = 40F DT Butane
70F + 44F = -114 DT Propane
48# X 0.39 SpHt X 40F DT = 749 BTU
39.6# X 0.39 SpHt X 114 DT = 1761 BTU
749 BTU / 165.6 BTU = 4.5 lbs Butane vaporized
1761 BTU / 184 BTU = 9.6 lbs Propane vaporized
-22” Hg is about the lowest practical pressure to run a TRS-21 without running the piston rings dry and according to the calculator at Boiling Point Calculator , at -22” Butane boils at -5C/23F and Propane at about -45C/-49F.
Hypothetically of course, my last question presumed there would be greater heat removal at sub atmosphere. I understand some folks vent tanks to lower their solvent temperature and I was curious how low they would go with a refrigerant pump. Not as low as I assumed. Thanks for mathing that one out. I’m glad I don’t run pumps.
Jesus, you guys truly are on another level I hope to absorb as much info from you guys as possible! Thanks for your in depth answers, explanations and maths!!
I have a semi-related question. I did my first solvent distillation today, it was a success, I recovered roughly 3lbs into that tank, but while i was doing it the cold bath (Alcohol and Dry Ice) were bubbling madly, as if i just poured the alcohol in. I’m assuming this is normal and just the cold bath cooling the now warmer tank with the warm butane getting converted into a liquid again? Thank you again everyone for being nice to my noob ass. lol
If it was truly a 125lb tank, then that was legit. most tanks sold to this industry are labeled based on how many lbs of WATER they hold (100% full)…but some folks actually state how much solvent will fit (100% full).
At this point I don’t trust anything but a tape measure and maths…
I put my denatured alcohol cans in the cooler of dry ice for an hour with the metal against the block of ice and I think it sublimates less. When I put it in the chiller coil cooler theres no bubbling
