Alright, so who here is gonna isolate terps and quantify the vapor pressures of each?? 
Could be useful data regarding this. Apparently limonene VP at 20c is 190 pascals which is nothing in PSI.
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This is something I have started to look into. What specific weight of cannabis oil can be fully decarbed down with respect to a specific/constant volume, constant temperature, and also without having to offgas the system in between.
Some of my better THCa to THC conversions using live hash rosin, without getting too much into detail, involved less input material leading to higher yields.
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The math has been done publicly a couple of times. Not to that end though. Care to give it a shot for the rest of the class?
THCA == 358g/mol
One mol thca == 1 mol co2
1mol ==> 22liters at SPT
PV=nRT
Solve for temp and container size.
(Folks use liter & kg almost interchangeably for 90% THC, but there are densities posted around here too)
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Challenge Accepted!!!
Okay so we are gonna cook down an unknown amount of cannabis oil (THCa to THC) while trying to retain terpene profile. Ideally, the only thing we should lose is CO2 gas from the THCa → THC conversion.
Let’s say we are using 16 oz mason jars to do this in an oven set to a temperature of 250 F. The pressure rating on a 16 oz mason jar according to various sources is about 30 - 40 psi. What is the appropriate amount of input material that should be used in the sealed mason jar to fully convert the THCa to THC?
PV = nRT
P = pressure = 30 psi or 2.04 atm
V = volume = 16 oz or 0.47 L
n = moles = unknown
R = ideal gas constant = 0.08206 atmL/molek
T = temperature = 250 F or 394.3 K
Plug it all in…
PV = nRT
n = PV/RT
n = [(2.04 atm)(0.47 L)] / [(0.08206 atmL/molK)(394.3 K)]
n = 0.029632 moles CO2
0.029632 moles CO2 = 0.029632 moles THCa
0.029632 moles THCa * 358 g/mol THCa = 10.6 g THCa
Using a 16 oz jar @ 250 F to decarb cannabis oil under pressure, you can use 10.6 g cannabis oil (abiding by the 30 psi pressure rating of the mason jar) or all the way up to 14.1 g (using the 40 psi pressure rating).
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Which is quite different from what some folks are doing…
… and consistent with the “leave lots of headroom” the previous calculations have recommended.
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Could you elaborate off the top of your head?…
Filling their containers 2/3full…or more
Right, because the issue with decarbing in a closed vessel is going to be the pressure created by the evolving co2 gas.
So, if you’re decarbing let’s say 200g in that 16 oz jar, and you leave a lid on it it’ll reach its maximum pressure long before you’ve fully decarbed isolate, but if that was 200g of HTE, and your HTE was 30-50% THCa now it’s more like 60-100g of THCa, but that would still exceed the vapor pressure considerably.
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Interesting, I wonder what could be done with your rig that resembles a diamond miner. Certainly might be able to do some weight with appropriate cool down and off gassing in between.
@CuriousChemist22 right! Would be great to be able to pull a vacuum on the container before applying the heat and add just a spray of inert in there. With the negative pressure head space, could potentially have 50 percent more input material at least…
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You are correct that I meant F, my mistake!
And lots of valuable information here and thank you very much everyone. I can’t seem to figure out how to reply to multiple people without cluttering up this thread but this is why I love this place
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The Google says that this terpene science has already been done. Here is an example from the 1920s. Perhaps not as accurate as any new science. We we don’t have to start from scratch. There is also some mono-terpene science being done from 2010. So yay!
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I would definitely give it a try if I could. Unfortunately my lab shut down like 6 weeks ago and I’m currently out of a job. Fucking dumb ass ceo wasted all our capital on bullshit. Lol you hiring by any chance?
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No, we’re brothers in unemployment 
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Fuuuck this industry went to shit real quick
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Yeah I’m trying to transfer my skills to another industry. I might be done with cannabis xD maybe I’ll try to find something that moves parallel with it. Somehow get into cannabis real estate maybe?? Not sure. The world is our oyster as they say!
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It truly is dying, I’ve been debating taking HVAC classes and going that route
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Ya I’m currently looking into all sorts of new industries. It fucking sucks after being in the cannabis industry for 15 years, running my company for 10 years and now possibly having to move in with my parents and literally start over in life. Never saw this coming. I was probably too naive
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always looking for good hlep but we are in canda
As others have told you, it’s trapped CO2. When you decarb with the lid on there you have to get the CO2 out afterwards. Use centrifuge or magnetic stir pill for starters. You might even be able to just stir it well. Have you tried decarbing with the lids removed?
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Just had a jar totally bubble over =x good read here usually get some foam but this was champagne haha