--Added 2/14 on page two propane extraction with clean propane --
First, this is a description of what I consider a failed experiment. Someone might be able to make this work, and what I played around with is certainly a good start, but it wasn't as easy as I had hoped, so I'm not pursuing it any more.
This started when I bought these 2 high pressure cylinders as part of revamping my closed butane hash oil system; and fwiw, I have a new better, pumpless way to do that that I will show you guys soon enough. But I started thinking about how a high pressure column could be used to clean up dirty mercaptan doped propane. So thats how it started.
why even consider propane? Well, its cheaper, you can get big tanks of it, and in some essential oil extractions, it is considered superior.
What are the "cons"
-it is impossible to find clean propane. Unlike butane that we all obtain from cigar lighter sources, there is no such similiar source of propane that I know of. Sure, you can probably get some lab grade, or someone might have a specialty source, but you wouldnt consider it readily available. Propane, like butane, when sold for common fuel, is tainted with ethyl mercaptan for safety.
-propane has a much higher pressure than butane, so a couple of practical issues come up.
anyway - here is what I did, and what happened. I investigated and found that 3 different adsorbent materials were known to bind up mercaptans pretty well. activated charcoal, Sorbead R ©, and Molecular Seive #13 . All are pretty cheap and readily available. For instance they use one or all to clean up scuba air, and they are all used in one fashion or another to remove mercaptans from natural gas or propane in certain industrial situations.
So I filled up one of these 12 inch, 250 psi, stainless cylinders, they are commercial water filter housings, I filled one with 1/3 active charcoal, 1/3 Molecular Seive #13, and 1/3 Sorbead R. Hedging my bets. When you run liquid propane through it, it gets all of the obvious smell out. Hooray it would seem.
I even tested it with a test kit. I bought a High sensitivity Gastec© total mercaptan kit, and I spoke with the tech guy at gastec. He said that you could use their sensitive test tubes to check for "trace" mercaptans. Instead of using their standardized method, ie pulling 100 cc of the air through the tube over the course of 10 seconds, you just hook it up to a vacuum pump and pull tons of air through. Its not calibrated, but it does become very sensitive. The test tubes test accurately down to .1 ppm, and he guessed that a continuous flow of air with a vacuum pump could test down to .005 ppm.
So these test tube things just light up crazy when you run them, just in the open air if you have spilled any propane recently, even if you cant smell it. and suppossedly you can detect mercaptans down to 2.8 ppb by smell, which should be more sensitive than these test kits. anyway, I was trying to be scientific.
The kits couldnt detect a trace of mercaptan after it ran through the column of 3 different adsorbents.
So I took an ounce of bud, and ran the propane through the adsorbent column, and then through the column that had an ouce of bud in it. You run it through at pressure, otherwise the cylinders get cold quickly, and I doubt the extraction would do much at -44F, the temp that it would get to without pressure. Then once the propane sits in the adsorbent column for a few minutes, you transfer it to the column with the pot in it, and then I blew it into a 5 gallon bucket with a Teflon pail liner in it.
All seemed to be going well, but as the oil formed, and it is an almost white oil, as it purged, you could smell the sulfur mercaptans in it. Not much, but enought that I wouldn't want to smoke it. I haven't weighed the yeild, but it looked typical.
I repeated it with only the Molecular Seive #13, the adsorbent that should be the best, and sure enough it was quite a bit better. In fact I couldnt even smell the mercaptan in the oil as it purged, but I have a friend who is younger and seems to have a better nose than me, and he could smell it in the purging whitish oil.
I won't be throwing the fail oil away, Ill make something edible out of it, maybe some capsules. That tiny amount of mercaptans certainly isnt a health hazard, but who would want to smoke something that smelled of rotten eggs?
So Im sure this could work if you use a bigger column and used just Molecular seive #13. The Pentek housings I chose come in 12 inch, 24 inch, and 36 inch. If I wanted to pursue this, I would use a 36 inch column for the adsorbent, and a 12 inch one for the pot, they hold 3+ ounces of bud at a time.
And just a heads up if someone tries to mess with this down the road, you cant use a regular gas grill cylinder. You use a forklift tank, they have a liquid draw spigot and have high flows if you change out the native adapter to a 1/4 flare.
First, this is a description of what I consider a failed experiment. Someone might be able to make this work, and what I played around with is certainly a good start, but it wasn't as easy as I had hoped, so I'm not pursuing it any more.
This started when I bought these 2 high pressure cylinders as part of revamping my closed butane hash oil system; and fwiw, I have a new better, pumpless way to do that that I will show you guys soon enough. But I started thinking about how a high pressure column could be used to clean up dirty mercaptan doped propane. So thats how it started.
why even consider propane? Well, its cheaper, you can get big tanks of it, and in some essential oil extractions, it is considered superior.
What are the "cons"
-it is impossible to find clean propane. Unlike butane that we all obtain from cigar lighter sources, there is no such similiar source of propane that I know of. Sure, you can probably get some lab grade, or someone might have a specialty source, but you wouldnt consider it readily available. Propane, like butane, when sold for common fuel, is tainted with ethyl mercaptan for safety.
-propane has a much higher pressure than butane, so a couple of practical issues come up.
anyway - here is what I did, and what happened. I investigated and found that 3 different adsorbent materials were known to bind up mercaptans pretty well. activated charcoal, Sorbead R ©, and Molecular Seive #13 . All are pretty cheap and readily available. For instance they use one or all to clean up scuba air, and they are all used in one fashion or another to remove mercaptans from natural gas or propane in certain industrial situations.
So I filled up one of these 12 inch, 250 psi, stainless cylinders, they are commercial water filter housings, I filled one with 1/3 active charcoal, 1/3 Molecular Seive #13, and 1/3 Sorbead R. Hedging my bets. When you run liquid propane through it, it gets all of the obvious smell out. Hooray it would seem.
I even tested it with a test kit. I bought a High sensitivity Gastec© total mercaptan kit, and I spoke with the tech guy at gastec. He said that you could use their sensitive test tubes to check for "trace" mercaptans. Instead of using their standardized method, ie pulling 100 cc of the air through the tube over the course of 10 seconds, you just hook it up to a vacuum pump and pull tons of air through. Its not calibrated, but it does become very sensitive. The test tubes test accurately down to .1 ppm, and he guessed that a continuous flow of air with a vacuum pump could test down to .005 ppm.
So these test tube things just light up crazy when you run them, just in the open air if you have spilled any propane recently, even if you cant smell it. and suppossedly you can detect mercaptans down to 2.8 ppb by smell, which should be more sensitive than these test kits. anyway, I was trying to be scientific.
The kits couldnt detect a trace of mercaptan after it ran through the column of 3 different adsorbents.
So I took an ounce of bud, and ran the propane through the adsorbent column, and then through the column that had an ouce of bud in it. You run it through at pressure, otherwise the cylinders get cold quickly, and I doubt the extraction would do much at -44F, the temp that it would get to without pressure. Then once the propane sits in the adsorbent column for a few minutes, you transfer it to the column with the pot in it, and then I blew it into a 5 gallon bucket with a Teflon pail liner in it.
All seemed to be going well, but as the oil formed, and it is an almost white oil, as it purged, you could smell the sulfur mercaptans in it. Not much, but enought that I wouldn't want to smoke it. I haven't weighed the yeild, but it looked typical.
I repeated it with only the Molecular Seive #13, the adsorbent that should be the best, and sure enough it was quite a bit better. In fact I couldnt even smell the mercaptan in the oil as it purged, but I have a friend who is younger and seems to have a better nose than me, and he could smell it in the purging whitish oil.
I won't be throwing the fail oil away, Ill make something edible out of it, maybe some capsules. That tiny amount of mercaptans certainly isnt a health hazard, but who would want to smoke something that smelled of rotten eggs?
So Im sure this could work if you use a bigger column and used just Molecular seive #13. The Pentek housings I chose come in 12 inch, 24 inch, and 36 inch. If I wanted to pursue this, I would use a 36 inch column for the adsorbent, and a 12 inch one for the pot, they hold 3+ ounces of bud at a time.
And just a heads up if someone tries to mess with this down the road, you cant use a regular gas grill cylinder. You use a forklift tank, they have a liquid draw spigot and have high flows if you change out the native adapter to a 1/4 flare.
