Passive Recovery Time

Did a run today and my passive recovery times were terrible!

My recovery tank is the same as the supply tank and I’m wondering if not pulling a vacuum on it is the reason it’s been so slow. I’m talking like 3.5 hours at this point for 10lb.

Here’s my procedure just for reference:

System other than recovery tank, as mentioned prior, under vac (all lines)
~2LB bidirectional column (didn’t run dewaxing column today)
10 lb solvent
Spool buried in dry ice
Supply tank on scale, disconnected when gas stopped flowing
Removed column. Still had a lot more gas than I’d like to be wasting, but it was no longer flowing into the spool.
Removed spool from dry ice
Placed supply (now recovery) tank into dry ice right side up with recovery line connected to the vapor port
Placed collection spool into 90-100*F water which I cycle out (have a jacketed platter I’m going to try using next)
Still waiting on recovery… 3.5 hours later.

Would speeds be considerably improved by having a recovery vessel under vacuum? My only concern here is operating a standard vac pump with a vessel containing trace amounts of 70/30 butane propane.

Trying to make passive work on this new system guys, I need your help though!

Thanks in advance, this is the best community around.


Try making your bucket of dry ice a slurry. Connect to the liquid line for recovery, that’ll help. Keep the spool in dry ice for a few more minutes and let all of your solvent suck itself down. If you are going to be doing that. You’ll want to have your tank collection under vac before putting it on dry ice and letting it stay for a while to get to temp. That should help suck all the gas down. Once you have done that, then close off column. You’re going to have left over though. Take your collection out and let it get to room temp, and not dunk it straight into warm water . This whole time you will need your tank cooling as cold as effin possible. It’ll create its own vacuum being that cold. Make sure when you connect to the tank, you clear the hose of any atmosphere. And then switch the collection to warm water. See how that goes.


So is there a way to remove 100% of solvent from a tank in order to make it safe to pull a vac? Or is it simply just not safe to pull a vac on a tank that has had solvent in it?


You can have a source solvent tank(big tank) and a recovery tank. The recovery tank you only put 10lbs. Extract with that recovery tank. Then vac it down and recover to it. When you need more butane. Top it off from the source tank as needed


If it was cold enough, it would be creating a vacuum. If you had something in there creating pressure. Then that’s different


So it is safe to vac a empty recovery tank despite there being residual solvent? That’s the only thing I’m uncomfortable with, as I know it’s hard to get 100% of the gas out of a tank.


Open the valve and let it vent for a min or two and yes. That’s how I’ve done it.


When you open it and vent it out, turn it upside down and let it push the solvent out the vapor port. Then pull vac on the tank. Ya?


Roger that. Read somewhere it wasn’t safe to use a normal vacuum pump on a tank that had solvent in it regardless if it was “emptied” due to residuals. Healthy respect for my combustible gasses…


What are ya’lls tricks for removing gas from the column? I’m thinking my losses were the result of several different factors but I can’t be losing 3lb every run.

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When i use 8lbs of tane i lose about 1-1.5 lbs per run. Which is 4 cans so i cant complain. Im curious about pushing column gas out too, could use nitrogen maybe to push?


That’s what I was wondering too and I’ve seen a little talk about it but nothing substantial enough to attempt replicating myself.

Right most people on here give good straight up help, but some give ya only a tailend and want ya to research ourselves, i understand cause knowledge isnt easy, but some of us cant afford trail and error, and have sick families to try to get the purest meds to. What do you use to set your collection pot in to warm it?

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I actually just purchased a jacketed base from BVV during their fire sale, got it for about $124 shipped afaik, amazing deal for a 10" base. I’m not using that today as I haven’t gotten the fittings for it, but in the future I’ll be using that along with my circulator to heat it to a precise temp and not mess with hot water baths. One of the reasons for this is I had a gasket blow when I dropped the spool into my hot water bath… shitty BVV gaskets. Can’t wait to upgrade em.


I alway empty my hot water bath then put my base in and top it off with fresh waTer. I had issues doing that also

If you are just vac’ing the empty tank with minimal vapors. Shouldn’t be a problem. After all the liquid is out. Vent it so it’s not pressurized and pull vac. Change your vac oil when you do this, if you do frequently, use grade 20 or better yet grade 19 vac oil.

I vac all the nitro out of my system each use. My tank is -75 at all times. What vapors are just nitro and minimal, minimal hydrocarbon vapors. It is something that you should have a little knowledge and knowhow to do.

I use nitro to push the remaining solvent out of my column, but I definitely do have a loss each run.

I get busy and forget to reply sometimes, I apologize, but if you remind me. I’ll answer your questions when I can.


And we are definitely here to help, but not hold hands. A lot of us will give vague answers because we want you to learn what we are saying and not just show you how without you not understanding what’s going on. That could be potentially dangerous if you don’t understand what you are doing. But, I am more than happy to help you understand how and what is happening


If your unit is sealed properly u need large rectangle cooler and a sous vide!!!

OMG best thing I ever got, was so sick dumping and refilling that water!
Will heat the water for you set and forget


I just ordered one. Im going to give ut a try next week


I have a jacketed base and collection pot. i think its 14" or so (12" mouth opening) If i only had the jacketed base and not the spool I would be banging my head against the wall. It wouldnt make enough heat to recover a full pot efficiently until it got way down to the bottom hours later. You would have to recover while you’re blasting and that wouldnt work because the collection pot needs to be constantly warmed to recover.

I have a polyscience immersion heater in a bucket containing a coil, and a pump circulates alcohol through the coil and to the jacket and back (closed loop)

Also what kind of bio-mass are you starting with? Trim, nugs, fresh frozen? I have a molecular seive in line between the collection pot and recovery tank to keep the tane dry.

When youre doing fresh frozen or nug-run you are really concentrating on getting the color light so you may not pull all the tane from the material column of it heats up too much due to the passive nature of the system. Im making crude now so i pull every little drop I can.

A move i pull while recovering (crude) is to blast N into the sealed off material column to maybe 20 psi or so. Then open the bottom valve and (using the sight glass) the liquid tane which condenses at or near the bottom should pull through.