Neverending vac purge...

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WeirdWentPro

WeirdWentPro

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So I made bho for the first time in over a decade...the first time since the dark early days of PVC extraction tubes and no vaccuming. Glass extractor, appx 2 lbs of mostly bud...now my oil is sitting in a 9" round glass pyrex in a vaccum chamber and has been under almost constant heat+vac pressure for 3+ days and is still mostly cloudy and still purging...will it ever stop bubbling?

Not sure of amount but its about a 1/4" thick in the pyrex. Keeping temps low, chamber is on a seedling heat mat, the interior bottom reads between 90-100 , and I remove the pyrex a few times a day and bathe it it 120 degree water for a while to re-liquefy, then back into the chamber. Dont have a pressure gauge but its a Robinair vac pump that should be pulling close to 30 no problem, no leaks in the system.
 
squiggly

squiggly

3,277
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So I made bho for the first time in over a decade...the first time since the dark early days of PVC extraction tubes and no vaccuming. Glass extractor, appx 2 lbs of mostly bud...now my oil is sitting in a 9" round glass pyrex in a vaccum chamber and has been under almost constant heat+vac pressure for 3+ days and is still mostly cloudy and still purging...will it ever stop bubbling?

Not sure of amount but its about a 1/4" thick in the pyrex. Keeping temps low, chamber is on a seedling heat mat, the interior bottom reads between 90-100 , and I remove the pyrex a few times a day and bathe it it 120 degree water for a while to re-liquefy, then back into the chamber. Dont have a pressure gauge but its a Robinair vac pump that should be pulling close to 30 no problem, no leaks in the system.

The short answer is no, it will never stop purging. The long answer follows:

The butane cannot escape your oil because by now you have removed most of the butane and this increases the viscosity of your oil product. Butane is also quite non-polar which means it's really doesn't mind associating with your oil in the first place.

The purpose of the purge is to coax the stuff out of there--but an absolute requirement to doing this properly is dispersion of the product into a thin film.

Reducing the pressure removes the thermodynamic barrier to solvent escape--by causing the solvent to enter a gaseous state.

What you are encountering in the interim is that the top layers of oil in your dish actually form--through their high viscosity--a physical barrier to solvent escape from the lower layers.

This is why, in the lab, we use what is known as a thin-film evaporator or a rotary evaporator/rotovap. This disperses the sample into a very thin film while adding heat and exposing the thing film to reduced atmosphere.

The heat serves to reduce viscosity which in turn ensures that a thin film is dispersed in the flask. The majority of your oil is in the bottom of the flask--and many first and second year students make the mistake of believing that is where the action is (because when there is a lot of solvent it all "boils" out from this pool).

The magic of the rotovap really happens when most of the liquid has been reduced and there is basically only oil in the flask. At this point most of the solvent escape is coming from the thin film that has been dispersed on the top of the flask as it is rotated.

Long story short--1/4" is way too thick to get a clean purge. Find a solution that allows you to purge smaller runs in much thinner films. No more than a few millimeters. Sub-millimeter film is the standard for rotovaps and represents a best-case scenario.

If you have the dough and plan on doing this alot--buy a used rotovap. I can help you use the thing properly.
 
Graywolf

Graywolf

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What SQ said about thin films, and there is also the issue of decarboxylation. If you run it until it is bubble free, you will be there a long time at 100F.

The solvent leaves in irregularly shaped bubbles, and the CO2 in smaller more evenly sized bubbles.

We run in thin films and at 115F, because that is the temperature that the bubbles observably break free with the strains that we typically run. If you are able to break bubbles free at 90/100F, your oil has a lower viscosity than ours, which may be strain related, or indicate dillution.
 
HighBurn8

HighBurn8

69
18
What SQ said about thin films, and there is also the issue of decarboxylation. If you run it until it is bubble free, you will be there a long time at 100F.

The solvent leaves in irregularly shaped bubbles, and the CO2 in smaller more evenly sized bubbles.

We run in thin films and at 115F, because that is the temperature that the bubbles observably break free with the strains that we typically run. If you are able to break bubbles free at 90/100F, your oil has a lower viscosity than ours, which may be strain related, or indicate dillution.


Hi GW, quick question for ya... could the variation in elevation play a part in how much heat it takes to get the viscosity one needs to pop bubbles?
Cuz I live @ close to 2500 feet and noticed that i need to keep my temps really low or I get decarboxylation
 
SuperCan

SuperCan

63
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Hi GW, quick question for ya... could the variation in elevation play a part in how much heat it takes to get the viscosity one needs to pop bubbles?
Cuz I live @ close to 2500 feet and noticed that i need to keep my temps really low or I get decarboxylation

Inside the vacuum chamber the atmospheric pressure should be the same regardless of your elevation, 29.9mmHg. If you're talking about outside of a vacuum chamber, then absolutely elevation plays a role. Boiling and evaporation are processes which are inhibited by increased pressure. Decarboxylation will also be affected by pressure. Most chemical processes are. This is why chemical reactions are defined under 'standard conditions'. Often this is described as STP or 'Standard Temperature and Pressure' which is 0 degrees C (32F) and 1bar. 1bar ~ 1 atmosphere and 1 atmosphere = 760mmHg which is the approximate pressure at sea level. At higher elevations the pressure is lower and it is easier to boil things, there is less impedance on the molecules to prevent their escape from the liquid phase.
 
Graywolf

Graywolf

1,597
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Hi GW, quick question for ya... could the variation in elevation play a part in how much heat it takes to get the viscosity one needs to pop bubbles?
Cuz I live @ close to 2500 feet and noticed that i need to keep my temps really low or I get decarboxylation

The heat and pressure relationship stays the same with elevation. Things just boil at a lower temperature with elevation and a vacuum pump gauge won't read -29.92" Hg at full vacuum, because there is not the weight of a a full atmosphere to pull down to.

Here is a nice program and chart showing the difference:

http://www.trimen.pl/witek/calculators/wrzenie.html and


Ostensibly decarboxylation would happen at a lower temperature under vacuum as well, because the vapor pressure would be higher, but I wouldn't have a clue how to calculate it.

Under full vacuum, the pressure would be the same and the effects of the temperature should be the same, but it can vary by strain.

I would suggest putting a thin film in the vacuum chamber and pulling a full vacuum, before slowly raising the heat to see at what temperature the bubbles break free and dissipate.
 
SuperCan

SuperCan

63
18
Ostensibly decarboxylation would happen at a lower temperature under vacuum as well, because the vapor pressure would be higher, but I wouldn't have a clue how to calculate it.

As you probably guess graywolf (with your engineering background) it requires use of calculus, and more specifically diff eq. The necessary equations are below. This is technically chemistry but it resembles physics more than anything.



ΔrH០ = [Σ(products) vΔf Hm,]- [Σ(reactants) vΔf Hm,]
ΔrS០ = [Σ(products) vΔSm,]- [Σ(reactants) vΔSm,]

dH = dU + d(PV)
dU = dq + dw
dw = -PextdV
PV=nRT

dG=VdP - SdT + μadna + μbdnb + .....

μ = μ+ RTln (P/P)

where a negative value for ΔG is the 'fulcrom point' for the spontaneity of the reaction.

As this suggests you need good control over variables to figure out what the exact values are such that it's not worth it for making oil. At the end of the calculations we see that decarboxylation happens more readily under reduced pressure and less readily under increased pressure which should make sense and a similar argument can be made for temperature and entropy using Kirchoff's laws (but these require constant pressure because qp= ΔH).
 
Graywolf

Graywolf

1,597
263
As you probably guess graywolf (with your engineering background) it requires use of calculus, and more specifically diff eq. The necessary equations are below. This is technically chemistry but it resembles physics more than anything.



ΔrH០ = [Σ(products) vΔf Hm,]- [Σ(reactants) vΔf Hm,]
ΔrS០ = [Σ(products) vΔSm,]- [Σ(reactants) vΔSm,]

dH = dU + d(PV)
dU = dq + dw
dw = -PextdV
PV=nRT

dG=VdP - SdT + μadna + μbdnb + .....

μ = μ+ RTln (P/P)

where a negative value for ΔG is the 'fulcrom point' for the spontaneity of the reaction.

As this suggests you need good control over variables to figure out what the exact values are such that it's not worth it for making oil. At the end of the calculations we see that decarboxylation happens more readily under reduced pressure and less readily under increased pressure which should make sense and a similar argument can be made for temperature and entropy using Kirchoff's laws (but these require constant pressure because qp= ΔH).

Thanks for the formulas bro! One of the things that became clear during my engineering career, is that no person has all the answers and it takes a village to keep track of all the disciplines!
 
K

kolah

4,829
263
And there ya have it folks! Squiggs=Supercan

How many other usernames ya got? LOL
 
K

kolah

4,829
263
saved.

As you probably guess graywolf (with your engineering background) it requires use of calculus, and more specifically diff eq. The necessary equations are below. This is technically chemistry but it resembles physics more than anything.



ΔrH០ = [Σ(products) vΔf Hm,]- [Σ(reactants) vΔf Hm,]
ΔrS០ = [Σ(products) vΔSm,]- [Σ(reactants) vΔSm,]

dH = dU + d(PV)
dU = dq + dw
dw = -PextdV
PV=nRT

dG=VdP - SdT + μadna + μbdnb + .....

μ = μ+ RTln (P/P)

where a negative value for ΔG is the 'fulcrom point' for the spontaneity of the reaction.

As this suggests you need good control over variables to figure out what the exact values are such that it's not worth it for making oil. At the end of the calculations we see that decarboxylation happens more readily under reduced pressure and less readily under increased pressure which should make sense and a similar argument can be made for temperature and entropy using Kirchoff's laws (but these require constant pressure because qp= ΔH).
 
SuperCan

SuperCan

63
18
Squiggly must have a monopoly on chemistry because no one in the world has ever graduated from college before. I learned and used these equations before he was born if you ask graywolf I bet you he's seen a few of those equations before and used them. Is he squiggly too? Let me guess anyone who disagrees with you and doesn't have their head stuck up their ass is squiggly its so sad that you hate him so much you need to make up a new 'him' to attack now that he's gone. Unlike squiggly I have noticed there is a ignore button and I will use it! Goodbye forever asshole!
 
SuperCan

SuperCan

63
18
Thanks for the formulas bro! One of the things that became clear during my engineering career, is that no person has all the answers and it takes a village to keep track of all the disciplines!

Isn't that the truth!! We had to use these all the time in our lab because they can have a lot of effects on enzyme kinetics and some of the things we tested for were GLUT4 deficiency which diabetics have and other protein deficiencies. It was my job to to create all of the standards in the lab and these had to be constantly updated as more precise methods became available. When you are in school you think that everything comes from a book or from journals or I guess these days from the internet but when you get into the field you realize that to do testing you have to make standards in your own lab with your own equipment to be able to say you got the results that you did. It turns out that I made a living out of that!! When I graduated from college (1988) the field of biology had a crutch like dependence on chemistry, physics, and math because we were still in the process of figuring out the stuff that the new biology graduates learn about in school now and the only exception to that was the behavioral biologists like Jane Goodall and some people in the medical field who had built enough knowledge to make it its own discipline. Now biology has become a field in its own right from top to bottom and the new graduates we brought in as assistants floored me with their knowledge levels in fact since we are on the topic they reminded me a lot of squiggly but just with biology instead of chemistry. We still made them wash the glassware but they were damn smart hehehe!
 
Graywolf

Graywolf

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263
Calculus and difEQ were, part of our curriculum as well, but I truly didn't really understand any math, until I had my first engineering project requiring it. I didn't remember what to do, but remembered which book the formula was in and after applying it to a practical problem that was real one time, never ever had to look it up again. That was because I saw the relationship and understood what they were doing.

It is mostly by working in my field that I understand what I do, and have always made a point to cultivate relationships with bright folks expert in their own fields, to guide me in areas that I don't fully understand.

To the issue of conflict, my training and experience leading think tanks, leads me to believe that our individual personality types can be divided into at least three, if not four different groups. Some personality styles are diametrically opposed to one another, but each has its place in the overall scheme and without their balancing influence, the results are less perfect.

For instance, a Directive might be a big picture guy focusing on the big project picture, to make sure it is completed on schedule, within budget, and within spec, while a Precisive might be meticulously going over each detail twice, to make sure there is no possibility for error.

During that same period, any Emotives would be focused on keeping the group cohesive, by focusing more on interpersonal issues, that the other two styles.

The point is, that without anyone of the three styles, a project has less chance of success, because the Precisive will drive the Directives up a tree meticulously going over detail and adding to elapsed project time, but without the attention to detail, it may look like a widget, but it won't start up and run when you turn the key.

Without the Directive, the project might never be completely closed, much less on time, and without the Emotives, the Precisives may not stick around.

However you slice it, we produce a better thoughtout product, when we share and debate our views, as long as it is fair argumentation.

Fair argumentation says that we focus on the issue, not on the messenger. That keeps egoes and emotions from leaping into play, and diverting the central issue, besides squelshing valuble resoures.

The issue can be a scientific (??) fact, or even an action taken by a participant, but not the personal shortfalls of the individual themselves.

Also consider that most often someone that is highly gifted in a specific area, is not paying close attention to others, so they're not always socially graceful. Anyone paying attention to all areas, isn't very focused on any of them, even if they are neater to be around.

If we considered each other as cells of the same body, how would that change the way we treat each other?
 
SuperCan

SuperCan

63
18
Calculus and difEQ were, part of our curriculum as well, but I truly didn't really understand any math, until I had my first engineering project requiring it. I didn't remember what to do, but remembered which book the formula was in and after applying it to a practical problem that was real one time, never ever had to look it up again. That was because I saw the relationship and understood what they were doing.

If we considered each other as cells of the same body, how would that change the way we treat each other?

I agree! I forgot all of the math as fast as I learned it until I had to use it again this was the stuff that I ended up using the most often over 25 years because in biology and biochemistry everyone want's stuff in terms of delta Gs because we do everything that constant pressure. You engineers use internal energy instead of enthalpy so often and so Id be mostly lost trying to do anything with that I believe the analog is delta A is that right?

If we treated each other as cells my guess is that kolah and I would be wishing apoptosis on each other I am definitely sending a healthy load of extrinsic inducers his way hehehehehe. I like how you explained everything though it makes sense that is why I always liked squiggly because even though I was not in research I am a lab bench junkie which I think he is too and that is what got him in trouble a lot is that he has not really gotten out into the world and seen that you can't do 'everything' from a bench. He is probably like me and needs the 'directive' to push him along a bit I am a 'precisive' and I believe squiggly is a 'precisive/emotive hybrid' or maybe just an emotive and that is why he 'kept me around' for his posts. Sometimes books and studies can't tell you what practicality can and he will figure that out eventually which is why I like him because I know I can trust that he will keep moving forward. On the other side I think that people who rely too much on their own experience without any reference frame for how to judge it are hamstrung too so it is a balancing act if you want to be the most successful.
 
K

kolah

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263
I agree! I forgot all of the math as fast as I learned it until I had to use it again this was the stuff that I ended up using the most often over 25 years because in biology and biochemistry everyone want's stuff in terms of delta Gs because we do everything that constant pressure. You engineers use internal energy instead of enthalpy so often and so Id be mostly lost trying to do anything with that I believe the analog is delta A is that right?

If we treated each other as cells my guess is that kolah and I would be wishing apoptosis on each other I am definitely sending a healthy load of extrinsic inducers his way hehehehehe. I like how you explained everything though it makes sense that is why I always liked squiggly because even though I was not in research I am a lab bench junkie which I think he is too and that is what got him in trouble a lot is that he has not really gotten out into the world and seen that you can't do 'everything' from a bench. He is probably like me and needs the 'directive' to push him along a bit I am a 'precisive' and I believe squiggly is a 'precisive/emotive hybrid' or maybe just an emotive and that is why he 'kept me around' for his posts. Sometimes books and studies can't tell you what practicality can and he will figure that out eventually which is why I like him because I know I can trust that he will keep moving forward. On the other side I think that people who rely too much on their own experience without any reference frame for how to judge it are hamstrung too so it is a balancing act if you want to be the most successful.

How many personalities do you have Squiggs? It's all very sad, ya know.
 
K

kushsmoker30

468
63
Thanks for the formulas bro! One of the things that became clear during my engineering career, is that no person has all the answers and it takes a village to keep track of all the disciplines!

Good stuff Graywolf that's how we tell a wise man apart from a fool....a Fool thinks he knows it all, n a wise man knows that in the grand scheme of life he don't know shit n is still open to listen n learn.
 
Graywolf

Graywolf

1,597
263
Yeah, the problem really is that the more we learn, the more we are aware of how little we do know.....................

Especially today, where some knowledge bases are changing faster than any ten people can keep up with....

Wonder how long before we have a chip implant to access all the data real time?
 
squiggly

squiggly

3,277
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How many personalities do you have Squiggs? It's all very sad, ya know.

Thought I'd jump in here quickly just to say:

I appreciate the flattery that you've bestowed on me by seeking to create your own personal squiggly to play with and keep your extra paranoid ass company while I've been away but (and I mean no offense to you SuperCan in saying this--I'm sure you'll understand), you could not pay me to write so many run on sentences or to fail to insert paragraph breaks where they belong. It is not in my blood to do such a thing.

My grandmother (a wonderful woman) was an English teacher and my mother--while she didn't give me much--was and is to this day a grammar Nazi. She gave me a brain and I'll be damned if I squander the one gift I got from her.

So while I accept your desperate pleas to "take out the trash" and expect them, fully, to continue--I felt the need to correct you here. I can't now nor will I ever be able to live in a world without punctuation; I am more likely to reduce all of my responses to one to two sentence replies.

It appears as though SuperCan doesn't really need my defense here, though, so I'll leave it there. He appears to have found his own "take out the trash" feature in the ignore button. I won't ignore you a second time, though, kolah. The shit you post is too hilariously bitter. I'm glad to have you back!

I'd lose moderator status 1000 times to gain the ability to watch you wring your hands so fervently. Your internet sweat is like ambrosia to my e-lips.

Again, thanks for tickling my funny-bone by missing me so much that you actually had to make your correspondence bias known to the rest of the farm. A word to the wise: that a person is educated beyond your understanding in a particular topic, or that they generally disagree with you, doesn't automatically mean that they are a bad person--and it especially does not mean that they are me. I suggest that if you believe it to be so, you should immediately climb the hell down your mountain of solitude and go to this magical place called a library where the knowledge of the world is at your fingertips. Also, in recent years, a newfangled approach to not being stupid has become popular among many folks, Americans especially, it's called Google.
Since I'm positive you probably don't know what the above emboldened term means, let me get you started out on the right path:

http://lmgtfy.com/?q=correspondence bias

Here's another you seemed to need

http://lmgtfy.com/?q=How to not be stupid

That said, back to your regularly scheduled awesome chemistry discussion happening in this thread which was so rudely interrupted by this exchange courtesy of yours truly vis-á-vis kolah.

PS


Can't logic just fucking check our IPs or some shit like that? I give full permission for him to do so if it will make you feel that much more retarded for thinking you're some CIA/FBI communications analyst and can't even tell the difference between someone with perfect grammar and someone who's written 2 paragraphs as one sentence.
 
squiggly

squiggly

3,277
263
At the end of the calculations we see that decarboxylation happens more readily under reduced pressure and less readily under increased pressure which should make sense and a similar argument can be made for temperature and entropy using Kirchoff's laws (but these require constant pressure because qp= ΔH).


This is true for decarboxylation if memory serves, but I want to make sure that people understand this can go in both directions. It's not as intuitive as it first seems (i.e pressure will tend to keep dissociable molecules/atoms attached to their parent molecules), it can in fact work in both directions.

Also, fuck Kirchoff's laws. I fucking hate physical chemistry lol. Especially the semester two shit, ughhhhhhh. Sciencebarf.
 

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