BUTANE EXTRACTION AND RECOVERY SYSTEM

[Gray Wolf]

Have you considered fitting some "extension" tube at the bottom of the column so that the butane oil mixture can flow into the bottom of a teflon bag for evaporation? It's mighty nice not having to deal with the extra step of scraping or rinsing with alcohol.

Yes I have considered it, but haven't done it yet.

I read your excellent post on the subject and you certainly make it look attractive, so I will try it out!

Both of my down tubes go to the bottom of the pot, so it would be easy to do so.

Is Welsh Fluorocarbon still the best source that you have found to date to purchase Teflon bags?
http://www.welchfluorocarbon.com/TeflonPFAFEPModifiedPTFELayFlatBags.htm

The reasons I haven't tried it yet, is that I redissolve much my BHO in alcohol anyway, so as to use freezing to coagulate the waxes, so that they can be easily filtered out.

I also am trying to develop our thin film BHO and thin film EtOh purging under vacuum processes, so have concentrated on those first.

Here is a picture of the bottom of my lid and one of a coffee filter used to filter out plant waxes from BHO after redissolving in EtOh and freezing overnight.

 

[foaf]

Welch is the only source I know of. For your thin film, there may be a way to line whatever you plan to use with Teflon. They make all sizes and thicknesses.

 

[jump117]

to develop our thin film BHO and thin film EtOh purging under vacuum processes,

I hope also for ethanol recovery

 

[Mud Man]

tagged

 

[christen23]

Very cool setup. Would LOVE to try some of the finished product! peace
~POE~

 

[Gray Wolf]

I hope also for ethanol recovery

Me too brother Jump.

I've operated the BHO system with a 12", a 24", and a 48" columns and Vacuum purged it to under 29" hg with the AC evacuation pump, after recovering the butane at around 20/22" hg, using the recovery pump.

With the 12" column, I can do a thin film vacuum purge of the BHO, but thin film vacuum purging of alcohol at ambient is still toooo slow at levels I have been able to achieve thus far at 26" hg, so I will be stepping up my efforts.

I am looking at building a high volume closed circuit water pumping system with multiple aspirators to get higher volume at pressures under -29" hg.

I will add a large diameter copper pipe cold trap that I can set in antifreeze and dry ice for recovery.

When the pool has evaporated, I can polish off with an evacuation down to microns levels with an AC evacuation pump, as part of the final thin film alcohol purge.

 

[G.O. Joe]

I am looking at building a high volume closed circuit water pumping system with multiple aspirators to get higher volume at pressures under -29" hg.

I will add a large diameter copper pipe cold trap that I can set in antifreeze and dry ice for recovery.

Ethylene glycol antifreeze freezes in dry ice, and you don't want a solid. Acetone, MEK, and the C1-C4 alcohols work fine, in a slush, for vacuum cold traps. Dry ice will freeze ethanol that contains water.

If there is no ball valve or other suckback protection, the vacuum line will suck water if the aspirator is turned off.

 

[Gray Wolf]

Hi ya'll! Still shaking this puppy out, and have made some notable discoveries that I thought I would pass on.

For starters here is the current configuration. My apologies for the scrawl, but my new 64 bit processor won't run my 2002 32 bit Auto CAD and they want $1,900 for the new 2012 64 bit program. Long since retired, that is hard to justify, so it looks like I will be setting up another computer with a 32 bit processor, just for design.

Up to this point, I have been pulling a -30 hg (gauge) vacuum on the entire system with valves (1), (2), (3), (4), and (6) open and valve (5) closed. I then let it sit to check for leak up rate.

If the system passes the leak check, I begin by flooding the column from the bottom. I do this by opening valve numbers (1), (2), and (5) until liquid butane flows out valve number (1), as evidenced by the sudden chilling of the vent line. I then close those three valves.

After a 10 minute soak, I open valves (1), (2), and (3), which allows the butane to drain to the collection vessel.

I then close valve (3) and open valve (5) to again flood the column, until it flows out of valve (1). I close valves (1), (2) and (5), and allow it to soak (5) minutes.

At this point I open valve (6) and start up the refrigerant recovery pump. If the recovery pump pumps the pressure down to zero before the soak time is up, I shut it off to reduce pump seal wear.

After a 5 minute soak, I open valves (1), (2), and (3), which allows the butane to drain to the collection vessel and again start up the recovery pump.

I then back flush the system, by closing valve (3) and opening valve (5). Once I feel the butane flowing out valve (1), I allow it to continue to flow out of the vent line controlled by valves (1) and (2) for an additional 10 seconds. I then close valve (5) and open valve (3) to drain the column, after which I repeat this complete back flush step. I do it twice for the 12" column, three times for the 24" column, and four times for the 48" column.

Adding this back flush step increased oil yield about 10%.

At this point, I continue to pump the whole system down using the refrigerant recovery pump, to about 21 inches hg, with valves (1), (2), (3), and (6) open and (4) and (5) closed.

When the system reaches 21", I close valve (6) and shut off the recovery pump. I then start up the vacuum pump and slowly open valve (4).

I continue to pump with the vacuum pump until the vacuum levels reach -30 inches on the analog gage, and then close valve (4) and shut off the vacuum pump.

I again watch the vacuum gauge and if the pressure starts to rise, I start up the vacuum pump again and open valve (4). I repeat this step until there is no pressure rise, and then either change out the column for the next run, or finish off the run.

To finish off the run, I let the pot sit for 30 minutes, to overnight under vacuum and with the pot heater plugged in.

To remove it from the pot, I wash it out with hot ethanol, which I filter and then place in the freezer overnight, so that the waxes and lipids coagulate and clump, which I then filter out.

I am still experimenting with ways to remove the alcohol. I have either distilled or cooked it off, or removed it by both heat and vacuum. I will cover those techniques in greater detail in that thread.

Here is a picture of the latest extract ready to go into the vacuum desiccator.

 

[eloquentsoution]

Skunk Pharm Research butane recycling system update:

Almost four years ago I began doing BHO extracting to formulate into concentrated medicine for my Alzheimer’s mother. Return on extracted flowers in the beginning was about 12%. With each improvement to our processing came a related increase in return of oil.

Last summer I did an extraction, using our butane recycling system, on some northern light resulting in a 22.2% return!

The latest revisions to our system include heating the collection chamber to speed the vaporization of spent butane in the hash oil and heating the column during the final purge and vacuum. These procedural changes resulted in a reduction in cycle time by 25% from one hour to 45 minutes. We still have a little tweaking before run time is established as fact. But we are happy with the improved efficiency.

In the process of testing the above, we ran some botrytis and pm laden flowers from an outside grow. After filtering, winterizing, re-filtering, vacuum filtering then pressing through a 0.2micron syringe filter, the resulting oil was pristine! I weighed it and ran the numbers, then again and again…..each time the results were the same….. an amazing 23.7% return in oil by dry weight of sifted flowers!!!! Even after loss from four rounds of filtering……

I take a bow to graywolf. My hat is off to you sir…..a fine engineer!!!

 

[Gray Wolf]

As we are discussing butane recycle, an update on our system, now that we have it shaken out and are moving on to the next generation. It is currently extracting around 25% oleoresin from bud and producing approximately 80 grams an hour, It runs a complete floor to floor cycle in 45 minutes. Butane recovery is 98 to 100%.

The current cycle pulls a 29.9" vacuum on the complete assembly and then floods one volume of butane through the column and out the top vent to the lower collection vessel, where it is pumped off. Every time the vacuum pressure in the lower vessel drops to -10"Hg, the column is flooded again, until 10 volumes pass though. A cycle takes approximately 1.5 to 2 minutes, and after the last flood, the column is drained out the lower valve and the system pulled down to -29.9 hg before opening to remove the fully purged bubble free oleoresin.

 

[prune]

In the process of testing the above, we ran some botrytis and pm laden flowers from an outside grow. After filtering, winterizing, re-filtering, vacuum filtering then pressing through a 0.2micron syringe filter, the resulting oil was pristine! I weighed it and ran the numbers, then again and again…..each time the results were the same….. an amazing 23.7% return in oil by dry weight of sifted flowers!!!! Even after loss from four rounds of filtering……

I take a bow to graywolf. My hat is off to you sir…..a fine engineer!!!

Do you have any numbers as to the amount of waxes and extraneous lipids that you are able to remove from the oil by winterizing, as a percentage of the oil?

 

[Gray Wolf]

Do you have any numbers as to the amount of waxes and extraneous lipids that you are able to remove from the oil by winterizing, as a percentage of the oil?

It varies by strain, but in the neighborhood of 1 to 2% of the 20/25% raw BHO oleoresin filters out during winterization.

 

[eloquentsoution]

gw is totally correct. i have had extractions with little to no waxes and others with very heavy wax, one that approached 6%. wish i had made note when it happened so i could give specifics...my bad.....

 

[prune]

If the amount is so low, why bother with winterization and it's concomitant higher purging temps? I smell so much flavor leaving the dish at temps much above 125f, i would really rather leave that essence in the product.

 

[Gray Wolf]

If the amount is so low, why bother with winterization and it's concomitant higher purging temps? I smell so much flavor leaving the dish at temps much above 125f, i would really rather leave that essence in the product.

Here are three quick reasons:

2%/20% = 10% inactive ingredients in the form of waxes and lipids. 10% more potent per unit volume is a significant number many places.

All of the floral flavor is also not lost, just reduced and we get lots of positive comments on flavor from the test panels. Some folks prefer the hash taste, to the more floral taste from raw BHO oleoresin or concrete.

The floral flavors only come into play when vaporizing, and most of our extractions go into oral meds, where other flavors are added anyway. If we want to retain more floral flavor, we can always use vacuum instead of heat.

 

[eloquentsoution]

i'll give you the reason i do it.....


the waxes cause me to caugh when i vaporize my oil. winterized oil is smooth to inhale!!!

to take less and still do the job, particularly for my alzheimers mother.

 

[Chunkypigs]

It looks like you have it dialed GW! The way I read your description the material in the tube is always soaking in a volume of butane? or does it just wash through the material and flow into the bottom collection vessel?

do you know how warm the butane gets in the lower chamber? i am thinking that adding heat makes it evaporate faster but the temp must rise during the final purge, no?

it's inspiring to see your commitment to great oil, thanks!

 

[prune]

Here are three quick reasons:

2%/20% = 10% inactive ingredients in the form of waxes and lipids. 10% more potent per unit volume is a significant number many places.

All of the floral flavor is also not lost, just reduced and we get lots of positive comments on flavor from the test panels. Some folks prefer the hash taste, to the more floral taste from raw BHO oleoresin or concrete.

The floral flavors only come into play when vaporizing, and most of our extractions go into oral meds, where other flavors are added anyway. If we want to retain more floral flavor, we can always use vacuum instead of heat.

Thanks to you and eloquent solution for your replies.

 

[Gray Wolf]

It looks like you have it dialed GW! The way I read your description the material in the tube is always soaking in a volume of butane? or does it just wash through the material and flow into the bottom collection vessel?

do you know how warm the butane gets in the lower chamber? i am thinking that adding heat makes it evaporate faster but the temp must rise during the final purge, no?

it's inspiring to see your commitment to great oil, thanks!

It soaks.

Butane in the lower chamber falls below freezing and the reaction grinds to a halt without heat. Until all the butane boils off, it is unlikely to rise above about -32C/0F. It can't rise above 100C/212F even when is all gone, because that is the maximum bath temperature.

 

[DIDM]

I wonder what freezing the material tube with liquid nitro would do


is there a temp where you you reach the point of negative returns?



or putting fresh in liquid nitro and making fresh frozen? They make ice cream with it, why not figure out a piping system that freezes the whole tube at nitro temps? Besides the nitro/butane bomb theory?