WeirdWentPro
- 11
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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.
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
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
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,០]- [Σ(reactants) vΔf Hm,០]
ΔrS០ = [Σ(products) vΔSm,០]- [Σ(reactants) vΔSm,០]
dH = dU + d(PV)
dU = dq + dw
dw = -PextdV
PV=nRT
dG=VdP - SdT + μadna + μbdnb + .....
μ = μ០ + RTln (P/P០)
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).
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,០]- [Σ(reactants) vΔf Hm,០]
ΔrS០ = [Σ(products) vΔSm,០]- [Σ(reactants) vΔSm,០]
dH = dU + d(PV)
dU = dq + dw
dw = -PextdV
PV=nRT
dG=VdP - SdT + μadna + μbdnb + .....
μ = μ០ + RTln (P/P០)
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!
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.
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!
How many personalities do you have Squiggs? It's all very sad, ya know.
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).
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