Vacuum distilling butane

Vacuum distillation

For those of ya'll wishing to vacuum distill your butane to remove any heavier components, before using it for extraction, here is a design for the cold trap that we will be using as a test sled, to not only vacuum distill the butane, for further polish filtering it through a Bentonite, zeolite, etc, column.

The way it works, is that the butane is injected into the cold trap as a liquid and pumped off as a vapor, leaving behind those things with a higher boiling point.

I set my cold trap in 85F water. You can do it without setting the trap in warm water, but as the butane boils off under vacuum, the transition from liquid to vapor, liberates the heat of vaporization, and plunges the temperature of the pool of butane to below its boiling point, so the process moves in starts and stops.

The next Alkane boils at about 36.1C/98.6F, at atmospheric pressure, so it is important to not heat the pot much beyond about 85F. The thermometer in the cold trap lid will tell you at what temperature your butane pool is during the cycle.

It is also important to not recover the butane below where the compound pressure gauge reads zero pressure, zero vacuum, or 14.7 PSIA.

PSIA is pounds per square inch absolute, which starts at absolute zero, without the weight of the atmosphere (at full vacuum). The atmosphere weighs 14.7 pounds per square inch, which is what a 1" column of mercury 29.92" tall weighs.

We do this operation outside and recommend that everyone do the same. Even though it is ostensibly a fully enclosed system, what if there is a leak or something goes wrong, goes wrong, goes wrong..........?

I recommend that you read and heed the thread on Butane Safety, before embarking on this journey. http://skunkpharmresearch.com/butane-safety/

Pull a full vacuum on the empty 50# refrigerant recovery tank for the first time, and valve it off.

Attach the pressure gauge to the cold trap via 1/4" refrigerant hose and pull a full vacuum on the trap, and valve it off, before assembling the system.

To vacuum distill using the cold trap, attach a 1/4" refrigerant hose to the inlet of the cold trap, and the other end to either an LP-5 tank of n-Butane, or to a can tapper, preferably with a ball valve attached at the tapper.

Attach the 1/2" outlet hose to the top of the filter section and the other end goes to the inlet of a refrigerant recovery pump.

We've used a couple of inexpensive brands for this purpose, namely the Appion G-5 twin and the CPS T-21, but neither are not rated by the manufacturer for butane, because they are not explosion proof should a leak occur.

Our larger commercial sized Mk V Terpenator will have the more expensive Caresaver Universal, or a Haskell pneumatic refrigerant recovery pump as an option, that are rated for flammable refrigerants, such as R-600 (n-Butane).
Depending on your situation, you should pick an option that fits your needs and safety needs.

The other hose goes to the red liquid dip tube valve on the 50# refrigerant recovery tank, which is sitting in an ice bath. If you really want to fly, set it in a denatured alcohol bath, with chunks of dry ice dropping the temperature to -70F or so.

Start the refrigerant recovery pump and the open the red valve on the refrigerant recovery tank, as well as the outlet valve on the cold trap.

If you are using an LP-5 tank of n-Butane, set the tank on a refrigerant scale and weigh it. Record the weight and push tare on the scale.

Open the inlet valve on the cold trap slowly and transfer about two liters of butane, or about 1146 grams, 2.5 lbs. Close the inlet valve.

The pressure gauge will have gone from -29.92" Hg vacuum, to positive pressure in the range of 10 to 30 psi. Watch until the pressure gauge drops to zero pressure, zero vacuum, and then load another 2 liters for distillation.

If you are using canned butane and a can tapper, close the valve at the can tapper, and open the inlet valve on the trap fully.

Tap the can and open the ball valve at the tapper. The pressure will rise from zero, to positive pressure. When the recovery pump lowers the pressure back to zero pressure, zero vacuum, close the valve at the tapper and tap a new can.

Open the valve to drain that can as well, and continue this cycle until all cans are empty.

Once you have emptied the LP-5 or the cans, when the pressure reaches zero again, close all valves and turn off the recovery pump.

Disconnect the hoses from the trap and open all valves to let it breath.

Remove the lid to the cold trap to remove the materials removed from the butane, and clean the trap with denatured alcohol for the next batch of butane.

Very impressive, but if you can buy butane from an industrial gas supplier that's already 99% pure, is further distillation necessary?

Were on the same wavelength brother!, your diy tek is pär excellent. Skunk Pharms and the Permaculture movement would love each other, the subject of polishing your solvent to resolve it's efficacy to lasik efficacy has been burning me up for 2 months. I did it the hard way and got a job to buy a refurbished labconco -55 refrigerated cold trap for my limonene oil. I saved up what reclaim I could get at faucet water tempuratures but it just won't condense enough to call it 90%. It made the best oil I have ever made and I didn't seem to struggle to eliminate any disproportionate ratios of limonene in the original super silver haze. My last run I ran out and had to chuck in some cold regular from the freezer. This mk ultra which is already a moisture pig just seems to not want to let go of this tangerine quality I can't taste in the green dense nuggests.

I am definitely with you on this distilling front, maybe we chat in the world of dreams at night if I'm unboxing while your posting. Dry Ice is really hard to get, more like there's only one place and it's monday to friday close at 4. It's becoming impossible to make the hour drive, or half burns away in the car all day while Im at work, double cooler and all. I found charcoal fltering my solvent for sport did change the nature of it's odour and temper it a bit, but I need distilling to crush this minute non volatile remainder that I thought was cinene but it may be oxidized limonene or micro stuff it's taking from it's container.

All I know is it seemed to add another atmosphere of depth to this art of alchemic engineering.

redi jedi said:

Very impressive, but if you can buy butane from an industrial gas supplier that's already 99% pure, is further distillation necessary?

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The butane that I removed the mystery oil from was certified to less than 50 ppm, which is 99.999950% pure.

SaybianTv said:

Were on the same wavelength brother!, your diy tek is pär excellent. Skunk Pharms and the Permaculture movement would love each other, the subject of polishing your solvent to resolve it's efficacy to lasik efficacy has been burning me up for 2 months. I did it the hard way and got a job to buy a refurbished labconco -55 refrigerated cold trap for my limonene oil. I saved up what reclaim I could get at faucet water tempuratures but it just won't condense enough to call it 90%. It made the best oil I have ever made and I didn't seem to struggle to eliminate any disproportionate ratios of limonene in the original super silver haze. My last run I ran out and had to chuck in some cold regular from the freezer. This mk ultra which is already a moisture pig just seems to not want to let go of this tangerine quality I can't taste in the green dense nuggests.

I am definitely with you on this distilling front, maybe we chat in the world of dreams at night if I'm unboxing while your posting. Dry Ice is really hard to get, more like there's only one place and it's monday to friday close at 4. It's becoming impossible to make the hour drive, or half burns away in the car all day while Im at work, double cooler and all. I found charcoal fltering my solvent for sport did change the nature of it's odour and temper it a bit, but I need distilling to crush this minute non volatile remainder that I thought was cinene but it may be oxidized limonene or micro stuff it's taking from it's container.

All I know is it seemed to add another atmosphere of depth to this art of alchemic engineering.View attachment 2816508

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You might take a look at dry ice makers, if you can get compressed C02.

Fadedawg said:

You might take a look at dry ice makers, if you can get compressed C02.

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I talked with the dry ice people several times about the economy of me renting a tank from them so I could make my own.
We did the cost curve vs repeatedly buying 10 pounds of dry ice " which is the minimum order ". It didn't add up for the amount of tank related red tape i'd have to pay in an out on a lease plus fill up. A large tank didn't hold much co2 once compressed, but I needed on demand low temps.
I ended up buying a large fire extinguisher that holds about 2 pounds total that i can refill for 10 bux locally to bypass the industrial gas supplier's co2 tank rental. Those Bel Art dry ice makers look awesome, but I also need dry ice for other greedy things like winterizing and freezing bud without waiting. I'm trying to find inch sized ball bearings, the kind people use as whiskey stones.
I figure if I dunk them in a -50 ethanol bath in the cold trap then towel them off, I can do multiple cooling jobs without the need for traditional dry ice. I don't expect the same runtime but I can always have fresh cold bearing exchanging out of my cold trap.

I'm hoping the $1500 dollar's spent can give me a 2 for 1 solvent recovery and "icy steel balls?" on demand dry ice alternative.

Wow!!!

Most excellent post FD!
As usual, Thank you for the continued effort in teaching the culture about the coveted hash oil.

Fade since were talking about the powers of cold, what would you say the winterizing curve would be on ethanol in cold trap conditions? I think some extract artist at least all of the production ones in my city can't handle the staging required to be in continuous production while still winterizing. I'm 3/4 pounds behind and I just got called into work sunday, i should be purging with that kind of delay but instead im winterizing that would set me back till tuesday. I'm eyeballing that cold trap again and thinking about what -50c/-58f can do for me when it comes to colapsing time. I always thought the 24/48 hour dance was more about the time it takes to coagulate under normal household freezers. I need to crush that dance down to an hour in a beaker that's sitting in an ethanol bath. I tried putting dry ice in the ethanol like an idiot in the past and all it did was give my freezer section a dab of solvent filled splash oil.

My brain just can't come up with a reasonable curve when it comes to degree's at X temperature to hour's needed to form filterable fat's at 1.5 micron before hitting the syringe filters.

SaybianTv said:

Fade since were talking about the powers of cold, what would you say the winterizing curve would be on ethanol in cold trap conditions? I think some extract artist at least all of the production ones in my city can't handle the staging required to be in continuous production while still winterizing. I'm 3/4 pounds behind and I just got called into work sunday, i should be purging with that kind of delay but instead im winterizing that would set me back till tuesday. I'm eyeballing that cold trap again and thinking about what -50c/-58f can do for me when it comes to colapsing time. I always thought the 24/48 hour dance was more about the time it takes to coagulate under normal household freezers. I need to crush that dance down to an hour in a beaker that's sitting in an ethanol bath. I tried putting dry ice in the ethanol like an idiot in the past and all it did was give my freezer section a dab of solvent filled splash oil.

My brain just can't come up with a reasonable curve when it comes to degree's at X temperature to hour's needed to form filterable fat's at 1.5 micron before hitting the syringe filters.

Click to expand...

Don't have a curve, but bho in ethanol winterizes good enough for filtration in a couple of hours in an alcohol/dry ice bath.

I tried it last night oh man I'm so excited, i let it cool in the -58f ethanol bath for a half hour and got huge fallout. I let it go another half hour, it formed that eerie entity mass in the middle. Half hour latter no change, I was happy as larry and the ratio of gakass was right so I didn't cut any corners. Next round I'll document it, i didn't think it would resolve so fast so I thought nothing of it. I'm not suggesting people do this if there not already in the business of reclaim and cold traps but this really made my purchase "worth it" for once. I just tried some and did the usual hold it till you breathe out nothing and it's far better than when I cut corners and took the 24 hour winterize stop.