There’s several methods of closed loop extractor articles floating around, however none are a baseline. This is the best way to operate a closed loop & locking off columns as an option can be used as well as boosting hot vapor to the top of the column. Inexperienced users should follow these instructions to ensure success in quality, proper extractions & rapid recovery.

There may be several companies that offer different methods, however non are a baseline. This is the best way to operate a closed loop and locking off columns as a option can be use as well as boosting hot vapor to the top of the column. As a beginner you should follow these steps to the dot if you want success in quality, proper extractions, and rapid recovery. Closed loop system equipment in order of connection :

  • solvent tank to top of column
  • collection column to filter drier
  • filter drier to pump
  • pump to chiller coil
  • chiller coil to solvent tank

Closed Loop System

There may also be a available bypass between the coil and feed line with a valve. This is uses for numerous purposes. The idea to remove the manifold and create a better feeding solution allows with this bypass to convert a throughput system in this manner to a looping system.

The proper closed loop basic operation is as follows. If your setup has the wrong hoses or valves and connection you also will not be able to accomplish this. Throughput/cryo/low temp etc, these operations are actually based on a complex effort and will not function if you are trying to save pennies to make benjies. You do not need a vale at the bottom of your machine to stall or hold fluid. Hydrocarbons have a amazing way of defying gravity, something even alcohol doesn’t have the ability to do. The common question i have is passive operations…can they be modified? No, not at all. You can get close but not close enough. I would always tell my students why would you get everything together and use a shitty machine that cannot do everything but is limited to only what it can handle. Why would you go so far and want to be soo good and simply settle for 75% of the quality or tech when you can go all the way.

In passive a major issue is people DO NOT understand passive is terrible. On the first run you ruin your butane. Passive recovery focuses on turbulence in the line, the more turbulence, then the more recovery effort with condensation. Without this increase in pressure that never goes away there will be no recovery. It is not a method where pressure is vented into the recovery tanks and stops to allow concurrent condensation of hydrocarbons. If this was the effect then recovery would be better and so would the butane when recovering. WITHOUT A DESICCANT DRIER anybody running passive should reconsider what they are doing. We do not want water or hydrocarbon end chains to end up in the solvent tank. If you go through the effort to get clean solvent, and then distill to get it pure, and then not use a drier properly your basically preparing one batch clean and ruining the remainder of your solvent and only making it worse.

Remember the desiccant drier setups aren’t made to clean your solvent in gas phase with psi rushing through it. I designed the desiccant drier years ago, and recently brought it forth – the concepts behind how it works are the theory that surround the appropriate handling of hydrocarbons. First off, no flat end caps will work, they will prevent the drier from operating. The mechanism of operation is as follows. The gas must decompress using the vapor dome end cap, and initially hit the core. This will absorb turbulence and will create a effect where the gas travels along the sides of the spool. Not the core. This will create massive cfm flow while allowing the gas to filter between the beads. The core will absorb water and contaminants and constantly attract such components towards the center. That is why end caps that are flat not only do not work, but also drag water with it because the gas does not freely move along the spool walls. The secondary effect is that fast moving gas doesn’t actually filter, it may bypass the beads, even if partially. The uses of recovery pumps are so important to this feature because they create a oscillating effect with the flow of the gas. This minuscule and split second where the gas technically stops and sits in the void is the theory where desiccant beads actually work. The filter driers do not like turbulence and they do not like constant flow. Even if i cannot describe the mathematical formula, i have worked closely with several engineers on this, learning that if a drier is not use properly it will not function properly. In a hydrocarbon still used for fuel fractioning at a petro plant these systems are staged, and designed to cycle over and over because the driers there have too much turbulence to control the actual single pass operation. This is why we do not like passive when it comes to cleaning hydrocarbons, and managing the purity and moisture content. We prefer pumps because they act as regulator in the process. The vapor dome end cap at the tail end of the drier will re-compress the flow of the gas, also removing turbulence as well which allows pumps to function much more smoothly.

You cannot use sister tank setups to try and achieve throughput, you cannot use tanks on the side with solvent in them on hot water to attempt to recreate what throughput does. This is because you cannot achieve the two points related to throughput. What is throughout? Throughput technically is when the system draws in vapor pressure 1.1x than is being supplied 1x. This will allow the system to augment the atmosphere and retain full liquid phases while also creating flow. Yea at -50f and 0 psi you can absolutely flow hydrocarbon fluids at full flow. In fact it will look like approx 20psi or 50psi in flow rates. Yes at 0psi if your system is setup correctly you can have full flow without any issues. If you cannot do this then you need to not only examine your connections and hose types, but also how your system is built. Incorrect connections, or small 2lb mismatched sizes will not operate because they lack the features to do so. Common issues are quick disconnect connections which act as governors and limit the system speed and efficiency. We have seen just one valve not only slow recovery down but cause leaks and make 0psi flow impossible. So remember if you cannot do what we are talking about here its because you were sold a bullshit closed loop that cannot perform. Period. The system either CAN of CANNOT do this. Any system setup like this can do anything every other system can do, but its not the same way around. Most systems can only accomplish one or two tasks at a time – and never be able to touch these performance features.

Closed Loop Extractor

We start with the process of preparing hardware.

Attach all hoses except the top of the column. Ensure at end of day every hose is held at vac, and when re installing hoses at next day that pump, and drier, are held at vac during hose assembly from previous day. Never expose to air.

Then feed nitrogen through your vessel (with all remainder valves still closed), the nitrogen will fill your vessel and dry out the steel as well as force nitrogen up through column. This will force as much moisture evident in the remainder atmosphere out. This will also partially dry out the material, you will do this at high rates near 40-50cuft on your gauge, it should spew out like crazy from the top of your column like a pressurized hose.

Slowly decrease the nitrogen flow while you are simultaneously closing the top of the column with your hose, and locking everything off. Do not allow nitrogen to compress your system as it may blow parts off and clamps. Nitrogen is so thin it WILL CREATE LEAKS in your cls even if you previously have not had leaked with butane, so always recheck everything during this process. NO EXCEPTIONS.

Now you can begin pulling vacuum. Nitrogen not only allows the force full flush of air and moisture from the immediate system and material but when re-vacuuming down your system you can accomplish deeper vacuum level FASTER while removing the remainder nitrogen compared to air. Air takes roughly 3x longer to evacuate to remove atmosphere from the system. Remember at this point all your hoses are at lock off and your bypass is open to allow the vacuum to remove all vapors from the lines. The pump and drier can still be locked off.

While the pump is running, wait until -30 is reached and now apply goretex sleeve and fill with dry ice. You will fill up the sleeve and let the vacuum pump run continuously while the column is chilling. Never ever, by any means chill a column without the vacuum pump running. This is a complex issue that we will not go into now, however this will help you gain very very stable product time out over and over again. Remember when the column is chilling never turn off vacuum until the last moment when you begin to flow your solvent. We suggest using goretex sleeves because you can dump and reuse 100% of the dry ice and utilize the chilling effect while its needed, and then remove it, while its not needed, and also save your dry ice. You will not lose any dry ice, but save it with this method. Remember chilling your column is only needed while dropping the temp, feeding, stalling and flushing, and temps should never stay low after the extraction is complete or else it may condense and just drip nonstop and cause recovery issues and damage recovery pump from operating at low pressures. The amount of dry ice used and saved actually pays itself off. Compared to a expensive chiller that requires lots of power and fluids to operate, were talking the loss of 5 dollars in dry ice or less and the ability to keep the ice afterwards to use in a chiller makes a goretex sleeve amazing tool in your arsenal.

Once the column is chilled down, turn off vacuum, close bypass to isolate lines, and begin feeding fluid from your feed valve to the top of the column. Once the sound decreases immediately open the pump and drier valves to open the path to the system and start your pump, while allowing both recovery and feed valves to be open. While the pump is running make sure the lower vessel and chiller coil are at room temp. This will become your driving force. While liquid is fed through the column the chilled effect before hand, and the solvent tank being in a freezer will allow the liquid to stay in liquid form, and not gassify during feeding. The goal is to take the liquid and relieve all vapor instances that may occur in the path and retain liquid phase. Allow pump to run while this is happening, look inside the machine, when approx a couple shot glasses of liquid come through to the vessel, immediately shut off the pump and close recovery and feed lines. During this time the pump will recover vapors and even drive a negative atmosphere environment and returning misc void gas back to the tank. Creating a vapor bubble that will help drive the 0psi fluid through the system. This cannot be accomplished any other way because no other way allows the removal of atmosphere with the flow of fluid at the same time to create THROUGHOUT. Once you shut the system down and close the valves the entire process will halt and you will physically stall the system.

NOTE: Before turning the system on into feeding you also have a bypass valve at top of column on a tee, and a bypass above the recovery line. This is used for pressure equalization and recovery from both vessel and top of column to prevent dripping and exchanges of heat to cold. If your column is cooler than your vessel it will automatically condense vapor from the hot system and start dripping and throwing down contamination and inactive compounds. The top recovery timing is essential to prevent anything like this from happening since the goal is to extract cold, flush cold, boost hot gas in column and heat it up. And then finally to recover while not compromising the process as a whole.

While the column is chilled with dry ice, and you have began filling and stopped the filling process, you also do not need a bottom column valve. This process will actually remove any void hydrocarbon fluid in the vessel that has dripped and will absorb it into the cold column. It will not drip and the fluid will stay in the column without ANY DRIPPING. This is a highly unknown effect, and should be remembered as the strongest extraction tool in your arsenal. Allowing throughout flow, and stall without valving anything off. Remember the vessel and coil and everything is at room temp. Nothing needs to be heated or chilled other than the column or you will change the atmospheric differential. And it will not work like designed. Your stall times can be 5-20 minutes depending on product, yield, and available compounds. One must note not to over pack a column. Remember your job isn’t to get as much out as possible including inactives and contaminants. Your goal is to do a selective extraction, and prevent contamination so the stall time to soak your product is extremely variable depending on the materials ability to release compounds into the solution for saturation. Also remember if you over pack – you will achieve a saturation level greater than what the fluid may hold. So essentially over packing can take contamination and bypassing the chemical compounds you are searching for.

After the desired stall turn the pump back on and open the feed and recovery lines. Right after the feed begins you put a bucket under the column and pull the zipper for the goretex jacket and immediately dump and removal all dry ice from the column. Right after the ice is gone from the column, you immediately put the coil in 140+ deg hot water in a small 1.5 gallon paint bucket. Get this out of the way so to speak. This will drive the process and complete the extraction. When you are comfortable with the lb fluid of solvent ran you can shut off the feed and recovery lines, RIGHT AFTER you open the bypass valve. Leaving the pump on. This will create a process used with gravity to begin flushing cold temp fluid out of the column. The next steps are very complex and must be followed to a t or else you will fail.

Once the bypass is opened and the feed and recovery valves are closed, you immediately need to engage the vast pressure differential to create a flowing process, if the flow is disrupted the process is altered and it can convolute the steps without knowing what you are doing. Think of it like this:

First fill.

Then soak.

Then flush.

During start of flush you dump dry ice.

Put coil in hot water.

Allow coil to heat up, while pump is running it returns hot vapor to tank.

Tank will create vapor bubble and help push fluid through straw.

When finished flushing.

Flip bypass.

Close tank valves.

This effort not only allows coil to heat up properly but also advances you to the next step.

When the bypass is initiated it will allow the natural vacuum of the system pull the fluid down without restriction. Note we like to use 5 and 10 micron, if you are not proficient with this process start at 50 and 20 and go to 20 and 10 and so on until you can run 10 and 5. the fluid should run very very very fast. As the natural vacuum and vessel at room temp will create some gas vapor the pump will capture – and send back to the top of column while it passes through a hot coil which transforms the pressure higher slightly. During this time the pressure differential will send pressure through the top of the column while the natural vacuum under it develops and draws the flow with gravity. When the fluid naturally stops flowing which should be about half way from draining the coil is prepared and very hot. Now add warmer water (100f) to the lower vessel. This will create a massive about of ambient vapor pressure and the pump will capture this and reloop it through the column and drive the flushing process further.

I mentioned these steps must be taken with care or you disrupt the process. You cannot just flip a switch and walk away you need to be aware of your surroundings. During this time you will see the column reheat up after it flushes fluid out. When the water initially exchanges temps, you must have hot water immediately read. Dump the current exchanged rate of warm water with new hot water. This will extend the process without lowering the pressure and creating condensing gas in the column. The point here is if you flush the fluid out and replace it with hot gas, it cannot extract but it can prepare the column for recovery so you don’t lose hydrocarbon gas during recovery. The whole process of adding warmer water and then immediately hot water will allow the system to progressively increase pressures. The pressure should be roughly 10-15psi higher at the coil gauge vs the vessel gauge by the end of the process RIGHT before the valves are switched to recovery. If you add hot water too fast it will shoot hot gas up the stem and stop the process entirely. This can create contamination and inactive compounds extractions. The concept here is to prep below 0 psi, feed, extract and flush fluids at low temps below 0psi, and then increase pressure once the phase of the column is flipped from a liquid to a gas. This also excites the column pressures and temps and prepares it for recovery because hot gasses recover faster than cold liquid content.

As the minutes go by(5 minutes or less) you will see the fluid slow down from the stem, and the column will be warm(periodically wipe water off it so it stays hotter faster). Once the column heats up, which is depended on how you run machine. For a champion run you would flush fluid out of column and use a valve to lock it off and simply remove it entirely while recovering. In some cases you can allow column to finish out the phase flipping and right at the moment when your chiller is 10-15psi higher than your vessel you immediately open the recovery port and close the bypass, while right after emerging your coil into dry ice after removing it from hot water and allowing 10 seconds to drain. This process is not initiating the chilling power on the coil and puts entire machine into recovery.

Right after this you have actually exchanged temperatures between the fluids super cold temperature for hot/warm; now is the time to set final recovery temperature, this may take a few minutes as the chiller will engage and 0psi recovery begins. At this point you will open your bypass valve between recovery line and top of column. This equalizes the pressure and grabs vapor from the top of the column. If done correctly the temperature of the system will always rise up with pressure, and the recovery of the top of the column prevents 99.5% of dripping from column. Nearly all contamination stays and DOES NOT redissolve. This process can be very tricky but with practice makes perfect. You want to remember the bypass valve is there for a reason, to close off during feeding and flushing, and to be opened for recovering from top of column. If you do not use this component properly it will add liquid butane to the pump and cause damage or just fill the condenser with fluids and recovering can be a issue.

If you do these steps and are proficient with these processes you will find recovery times of approx 1lb per minute. Higher temps can be ever faster. This is with pump and a 2 stage coil and a desiccant drier 3×12 spool size.

Before opening your system after achieving the depth of recovery, you want to make sure you inlet bypass and all other valves are shut off. As a operator you job is to make sure that air and moisture never enters your path. Something to consider if you plan to operate your machine over and over its also useful as leaving the lath where vapor travels down the path of drier, pump, coil; is isolated and when opening up your systems it keeps everything where it needs to me. The lid and the feed line is the only thing open and as we know by this point the feed line valve has been shut off. One way to make sure you don’t leave solvent in your coil or lines is to remove the coil from the dry ice and allow self condensing recovery for about the last 6 minutes,; this will literally let the coil to rewarm up to gas pressure temps and deice the coil within a minute or so. At the same time you want to turn off hot water feed to the water jacket, and allow the system to reach room temperature. Or else the column WILL super freeze and make recovery difficult. Towards the end you want the bottom vessel to be void of hot water as the inner surface will cool down from the recovery effort; this also removes vapor pressure. This task and timing is also key as you want to create a equal environment between the column and the material in the vessel. Just like the looping/bypass timing to create proper continual flow rates, this is essential to how the vapor equally recovers from the system. We practice this around 5psi in the system and let it run down to -5 at best. This allows the vapor pressure to shoot out fluid from the chiller. You can also put the chiller in warm water, and then when you close off the recovery valve for the end of the day you lose approx less than a ounce in vapor. Probably even less. Remember when removing the lines at the end of the day you want to immediately have your vessel already buttoned up so you can pump nitrogen back through the vessel and allow it to self travel through your beads, pump, coil to eliminate loaded content. This helps recharge the beads as well after each use. The get the best performance from this maintenance it is wise to wrap warm towels around the filter drier and put the coil in hot water. This makes the vapor warm and at high speeds literally strips moisture from the system and especially the condenser in the recovery pumps.

After you have let the nitrogen flow, you will immediately link up a vacuum pump to the main system. We like to use tees and run all lines together so they will be open to atmosphere through out the system and immediately pump down vacuum for about 30 minutes. All components must be void of typical atmosphere. When you have sank the vac gauge for a while then lock off all your valves on your system and shut off and disconnect the vacuum pump. You are now locked off and read for the next day.

We hope this helps people understand 0 psi recovery and how to safely run a machine. When i first practices all of these techniques minus top column recovery – it was years ago. People never heard or used throughout. When i came out with throughput people were still using hot tanks and chilling their lower vessels and still today i see throughput operation misused. This is the technical operating manual to THROUGHPUT i developed. Pump running, system self flowing, capable of high flow rates at 5 microns at 0 or below psi. If you dont have hoses, valves and components setup properly this will not be able to happen properly.

Our next section may contain different ways to run a machine, if you want your method published send detailed information and if it is deemed safe i will be happy to advise others on suitable options. -jbv